WO2021012149A1

WO2021012149A1 - Method and system for monitoring radiotherapy emitted beam

Info

Publication number: WO2021012149A1
Application number: PCT/CN2019/097085
Authority: WO
Inventors: 张艺宝; 黄宇亮; 吴昊; 李晨光
Original assignee: 北京市肿瘤防治研究所
Priority date: 2019-07-22
Filing date: 2019-07-22
Publication date: 2021-01-28
Also published as: CN112512632A; CN112512632B; CN110582328B; WO2021013020A1; CN110582328A

Abstract

A method (900) and system for monitoring a radiotherapy emitted beam. The method (900) for monitoring a radiotherapy emitted beam comprises: acquiring a reference standard image (910), wherein the reference standard image is determined on the basis of an imaging emitted beam image, and the imaging emitted beam image is generated on the basis of an emitted beam obtained by means of an imaging incident beam penetrating through a radiation object; acquiring a real-time treatment emitted beam image (920), wherein the real-time treatment emitted beam image is generated on the basis of an emitted beam obtained by means of a treatment incident beam penetrating through the radiation object during the current radiotherapy process; determining, on the basis of the real-time treatment emitted beam image and the reference standard image, whether a pixel value difference therebetween satisfies a preset condition (930); and controlling a radiotherapy process on the basis of a determination result (940), wherein the imaging incident beam and the treatment incident beam of radiotherapy are homogenous beams. The method (900) and system for monitoring a radiotherapy emitted beam can monitor the dose of a treatment emitted beam, thereby ensuring that the actual treatment meets the requirements of a plan design.

Description

Method and system for monitoring radiation treatment beam

Technical field

This application relates to the field of radiotherapy equipment, and in particular to a method and system for monitoring radiation therapy beams.

Background technique

Before performing radiotherapy on a patient, it is usually necessary to use a radiotherapy planning system (TPS) to design a radiotherapy treatment for the patient, determine a treatment plan, and then implement specific treatment for the patient according to the plan during the treatment process. To this end, this application provides a method for monitoring the emitted beam dose during radiotherapy.

Summary of the invention

One of the embodiments of the present application provides a method for monitoring radiation treatment beams. The radiation therapy exit beam monitoring method includes: acquiring a reference reference image; the reference reference image is determined based on an imaging exit beam image, and the imaging exit beam image is generated based on an exit beam obtained by an imaging incident beam passing through a radiation object; and acquiring real-time treatment Outgoing beam image; the real-time treatment outgoing beam image is generated based on the outgoing beam obtained by the treatment incident beam passing through the radiation object in the current radiotherapy process; the pixel value of both is determined based on the real-time treatment outgoing beam image and the reference reference image Whether the difference satisfies a preset condition; based on the judgment result, the radiotherapy process is controlled; wherein the imaging incident beam and the therapeutic incident beam of the radiotherapy are beams of the same energy level.

In some embodiments, the imaging incident beam and the treatment incident beam are from the same radiation source.

In some embodiments, the imaging beam image is acquired before radiotherapy.

In some embodiments, the imaged outgoing beam image is an image used for image guidance of user positioning before radiotherapy.

In some embodiments, determining the reference reference image based on the imaging beam image includes: performing position coordinate correction on the imaging beam image to obtain an initial reference reference image; performing processing on the initial reference reference image based on the treatment field The position is matched to obtain an area corresponding to the treatment field in the initial reference reference image, and the area is determined as the reference reference image.

In some embodiments, the performing position coordinate correction on the imaging beam image to obtain the initial reference reference image includes: acquiring the imaging isocenter position and the isocenter position of the treatment plan; based on the imaging isocenter position and the The correction position coordinates are determined by the difference between the center positions of the treatment plan and the like; and the position coordinate correction is performed on the imaging beam image based on the correction position coordinates.

In some embodiments, the performing position coordinate correction on the imaging beam image to obtain the initial reference reference image further includes: acquiring the angle of the collimator during imaging and the angle of the collimator of the treatment plan; determining the collimation during imaging The angle difference between the angle of the collimator and the angle of the collimator of the treatment plan; and the position coordinate correction of the imaging beam image is performed based on the angle difference.

In some embodiments, the performing position matching on the initial reference reference image based on the treatment field to obtain an area corresponding to the treatment field in the initial reference reference image includes: determining the treatment field based on the position data of the grating in the treatment plan , To generate a mask image; perform operations on the mask image and the initial reference image to obtain the corresponding area.

In some embodiments, generating a mask image based on the treatment field further includes: acquiring at least one treatment beam image; determining the boundary information of the actual treatment field based on the treatment beam image; verifying the treatment field based on the boundary information The mask image.

In some embodiments, determining the reference reference image based on the imaging beam image includes: determining a digitally reconstructed image of a planned CT image; the planned CT image is a CT scan image used to determine a treatment plan before treatment; Obtain an initial reference reference image based on the digitally reconstructed image of the planned CT image and the imaging beam image; perform position matching on the initial reference reference image based on the treatment field, and obtain the initial reference reference image corresponding to the treatment field Area, which is determined as the reference image.

In some embodiments, determining the digital reconstruction image of the planned CT image includes: calculating a plurality of projection data according to S ₀ * exp(-μL); and determining the digital reconstruction image of the planned CT image based on the plurality of projection data ; Among them, S ₀ is the empty scan signal minus the background value, the empty scan signal is the signal collected by the detector when the ray is only attenuated in the air, and the background value is the environmental signal collected by the detector when the radioactive source is not working; μ is the ray The average attenuation coefficient across the human body from one direction; L is the length of the part of the human body in the linear distance between the detector and the planned CT radiation source.

In some embodiments, obtaining the initial reference reference image based on the digitally reconstructed image of the planned CT and the imaging beam image includes: combining the digitally reconstructed image of the planned CT and the imaging based on an image registration algorithm The outgoing beam image is deformed and registered to obtain the initial reference reference image.

In some embodiments, the determining whether the pixel value difference between the real-time treatment beam image and the reference reference image meets a preset condition includes: based on the real-time treatment beam image and the reference reference image The image determines the pixel value ratio of the two corresponding pixel points; based on the pixel value ratio, it is determined whether the pixel value difference is within the tolerance range.

In some embodiments, the tolerance range is determined based on one or a combination of the following: signal-to-noise ratio, output factor, penumbra position, non-uniform ray influence, or equipment stability factor.

In some embodiments, a simulation experiment is performed based on the treatment plan to obtain a simulation ratio between the treatment beam image and the reference image; the allowable value range is determined based on the simulation ratio.

In some embodiments, the controlling the radiotherapy process based on the judgment result includes: stopping the current treatment when the pixel value difference exceeds the tolerance range.

One of the embodiments of the present application provides a radiation therapy exit beam monitoring system, including: an acquisition module for acquiring a reference reference image; the reference reference image is determined based on an imaging exit beam image, and the imaging exit beam image is based on an imaging entrance beam It is also used to obtain a real-time treatment beam image; the real-time treatment beam image is generated based on the beam generated by the treatment incident beam passing through the radiation object in the current radiotherapy process; the judgment module uses Based on the real-time treatment beam image and the reference reference image to determine whether the pixel value difference between the two meets a preset condition; the execution module is used to control the radiotherapy process based on the judgment result; wherein the imaging incident beam is The therapeutic incident beam of radiotherapy is a beam of the same energy level.

One of the embodiments of the present application provides a radiation therapy exit beam monitoring device, which includes a processor configured to execute the foregoing radiation therapy exit beam monitoring method.

One of the embodiments of the present application provides a computer-readable storage medium that stores computer instructions. After the computer reads the computer instructions in the storage medium, the computer executes the aforementioned radiation therapy beam monitoring method.

One of the embodiments of the present application provides a method for acquiring a reference reference image for radiotherapy, including: acquiring an exit beam obtained by an imaging incident beam passing through a radiation object, and generating an imaging exit beam image based on the exit beam; Perform position coordinate correction on the imaging beam image to obtain an initial reference reference image; perform position matching on the initial reference reference image based on the treatment field to obtain an area corresponding to the treatment field in the initial reference reference image, and determine the area as the Reference reference image; wherein the imaging incident beam and the therapeutic incident beam of the radiotherapy are beams of the same energy level.

One of the embodiments of the present application provides a system for acquiring a reference reference image for radiotherapy, including: an acquisition module for acquiring an outgoing beam obtained by an imaging incident beam passing through a radiation object, and generating an imaging outgoing beam image based on the outgoing beam The reference reference image determination module is used to perform position coordinate correction on the imaging beam image to obtain an initial reference reference image; perform position matching on the initial reference reference image based on the treatment field to obtain the initial reference reference image and the treatment field The corresponding area is determined as the reference reference image; wherein the imaging incident beam and the treatment incident beam of the radiotherapy are beams of the same energy level.

One of the embodiments of the present application provides a method for obtaining a reference reference image for radiotherapy, including: determining a digitally reconstructed image of a planned CT image; the planned CT image is a CT scan image used to determine a treatment plan before treatment ; Based on the digital reconstructed image of the planned CT image and the imaging beam image to obtain an initial reference reference image; position matching the initial reference reference image based on the treatment field to obtain the initial reference reference image corresponding to the treatment field The area is determined as the reference image.

One of the embodiments of the present application provides a system for acquiring a reference reference image for radiotherapy, including: an image reconstruction module, which determines a digital reconstruction image of a planned CT image; the planned CT image is before treatment and is used to determine a treatment plan A registration module to obtain an initial reference reference image based on the digitally reconstructed image of the planned CT image and the imaging beam image; a reference reference image determination module to position the initial reference reference image based on the treatment field Matching, obtaining an area corresponding to the treatment field in the initial reference reference image, and determining the area as the reference reference image.

One of the embodiments of the present application provides a device for acquiring a reference reference image for radiotherapy, wherein the device includes at least one processor and at least one memory; the at least one memory is used to store computer instructions; A processor is used to execute at least part of the computer instructions to implement the aforementioned method for acquiring a reference image for radiotherapy.

One of the embodiments of the present application provides a computer-readable storage medium that stores computer instructions. After the computer reads the computer instructions in the storage medium, the computer executes the aforementioned acquisition of radiotherapy reference images method.

Description of the drawings

This application will be further described in the form of exemplary embodiments, and these exemplary embodiments will be described in detail with the accompanying drawings. These embodiments are not restrictive. In these embodiments, the same number represents the same structure, in which:

Fig. 1 is a schematic diagram of an application scenario of a radiotherapy system according to some embodiments of the present application;

FIG. 2 is an exemplary schematic diagram of hardware and/or software components of an exemplary computing device that can implement a processing device according to some embodiments of the present application;

Fig. 3 is a block diagram of a radiation therapy beam monitoring system according to some embodiments of the present application;

4A is an exemplary flowchart of a method for determining a reference reference image according to some embodiments of the present application;

Fig. 4B is an exemplary flowchart of another method for determining a reference reference image according to some embodiments of the present application;

Fig. 5 is an exemplary schematic diagram of imaging isocenter and planned isocenter shift according to some embodiments of the present application;

6 is an exemplary schematic diagram of the conversion relationship between the three-dimensional correction amount and the two-dimensional imaging projection when the gantry angle is 30° according to some embodiments of the present application;

Fig. 7 is an exemplary schematic diagram of performing collimator angle correction on an initial imaging beam image according to some embodiments of the present application;

Fig. 8 is an exemplary flow chart of a method for determining a tolerance according to some embodiments of the present application;

Fig. 9 is an exemplary flow chart of a method for monitoring radiation therapy beams according to some embodiments of the present application;

10A is a comparison diagram of a verification experiment of radiation therapy beam monitoring when the weight of the phantom changes according to some embodiments of the present application;

10B is a comparison diagram of a verification experiment of radiation therapy beam monitoring when the internal tissue of the phantom changes according to some embodiments of the present application;

FIG. 10C is a comparison diagram of a verification experiment of radiation therapy beam monitoring when the phantom placement shown in some embodiments of the present application has different degrees of error.

Detailed ways

In order to explain the technical solutions of the embodiments of the present application more clearly, the following will briefly introduce the drawings that need to be used in the description of the embodiments. Obviously, the drawings in the following description are only some examples or embodiments of the application. For those of ordinary skill in the art, without creative work, the application can be applied to the application according to these drawings. Other similar scenarios. Unless it is obvious from the language environment or otherwise stated, the same reference numerals in the figures represent the same structure or operation.

It should be understood that the “system”, “device”, “unit” and/or “module” used herein is a method for distinguishing different components, elements, parts, parts, or assemblies of different levels. However, if other words can achieve the same purpose, the words can be replaced by other expressions.

As shown in the present application and claims, unless the context clearly indicates exceptions, the words "a", "an", "an" and/or "the" do not specifically refer to the singular, but may also include the plural. Generally speaking, the terms "including" and "including" only suggest that the clearly identified steps and elements are included, and these steps and elements do not constitute an exclusive list, and the method or device may also include other steps or elements.

A flowchart is used in this application to illustrate the operations performed by the system according to the embodiments of the application. It should be understood that the preceding or following operations are not necessarily performed exactly in order. Instead, the steps can be processed in reverse order or simultaneously. At the same time, you can also add other operations to these processes, or remove a step or several operations from these processes.

Fig. 1 is a schematic diagram of an application scenario of a radiotherapy system according to some embodiments of the present invention. As shown in FIG. 1, the radiotherapy system 100 includes a radiotherapy device 110, a network 120, one or more terminals 130, a processing device 140 and a storage device 150.

The radiotherapy apparatus 110 may deliver a radiation beam to a target object (for example, a patient or a phantom). In some embodiments, the radiotherapy device 110 may include a linear accelerator-111. The linear accelerator 111 may generate and emit a radiation beam (for example, an X-ray beam) from the treatment head 112. The radiation beam can pass through one or more collimators with a specific shape (for example, a multi-leaf grating) and be delivered to the target object. In some embodiments, the radiation beam may include electrons, photons, or any other type of radiation. In some embodiments, the energy exhibited by the radiation beam is in the megavolt range (ie, >1 MeV), so it can be referred to as a megavolt radiation beam. The treatment head 112 can be coupled with the frame 113 to be installed. The gantry 113 can rotate, for example, clockwise or counterclockwise about the gantry axis 114. The treatment head 112 can rotate together with the gantry 113. In some embodiments, the radiotherapy device 110 may include an imaging component 115. The imaging component 115 may receive a radiation beam passing through a target object, and may obtain a projected image of the patient during radiotherapy or an imaging process before and after radiotherapy, or may obtain a projected image of a phantom during correction. The radiation treatment system 100 can monitor the dose distribution during treatment through the treatment beam image acquired by the imaging component 115 to ensure that the actual treatment dose distribution meets the requirements of the treatment plan and the actual treatment dose distribution error is within the allowable range. The imaging component 115 may include an analog detector, a digital detector, or any combination thereof. The imaging assembly 115 can be attached to the frame 113 in any manner, including an expandable and retractable housing. Therefore, the rotating gantry 113 can make the treatment head 112 and the imaging assembly 115 rotate synchronously. In some embodiments, the radiotherapy apparatus 110 may also include a workbench. The table 116 may support the patient during radiotherapy or imaging, and/or support the phantom during the calibration process of the radiotherapy apparatus 110. The workbench can be adjusted according to different application scenarios. For example, the workbench can be translated along the X direction (patient left and right direction) and Y direction (patient dorsal and abdominal direction), and move in and out along the Z direction (patient toe direction). In practical applications, the directions of X, Y, and Z can be different for different devices, and the definition of the directions of X, Y, and Z is not limited to the aforementioned manner. In some embodiments, before radiotherapy, kilovolt energy level rays can be used to perform a planned CT (Computed Tomography) scan of the patient to obtain an image of the patient's anatomy (or called a localized CT image). Through the anatomical structure images, the patient's dose distribution is simulated and calculated and the radiotherapy plan is designed to determine the patient's treatment plan. In some embodiments, before each actual treatment, the radiotherapy equipment 110 can be used to scan the patient to obtain multi-angle imaging beam images, and to obtain three-dimensional treatment guidance images based on the multiple imaging beam images. The three-dimensional treatment guidance image is matched with the planned CT image, and the isocenter position of the radiotherapy device 110 is corrected. In some embodiments, the reference image may be obtained based on the first imaging beam image. During the treatment process, the treatment beam image is acquired based on the treatment beam, and the treatment beam image is compared with the reference image to monitor the treatment beam dose.

The network 120 may include any suitable network capable of facilitating the exchange of information and/or data of the radiation therapy system 100. In some embodiments, one or more components of the radiotherapy system 100 (for example, the radiotherapy device 110, the terminal 130, the processing device 140, the storage device 150, etc.) can communicate with one or more of the radiotherapy system 100 through the network 120. Exchange information and/or data between components. For example, the processing device 140 may obtain planning data from a treatment planning system (TPS) or a storage device 150 via the network 120. The processing device 140 may obtain the imaged outgoing beam image through the network 120 to obtain a reference reference image. The processing device 140 may also directly acquire the reference reference image through the network 120, and match the real-time acquired treatment beam image with the reference reference image to monitor whether the dose distribution of the actual treatment beam meets the planning requirements. The network 120 may include a public network (such as the Internet), a private network (such as a local area network (LAN), a wide area network (WAN), etc.), a wired network (such as an Ethernet), a wireless network (such as an 802.11 network, a wireless Wi-Fi network) Etc.), cellular network (for example, Long-Term Evolution (LTE) network), frame relay network, virtual private network (VPN), satellite network, telephone network, router, hub, server computer, etc., one or several combinations. For example, network 120 may include wired networks, fiber optic networks, telecommunications networks, local area networks, wireless local area network (WLAN), metropolitan area network (MAN), public switched telephone network (PSTN), Bluetooth ^(TM) network, the ZigBee ^TM network, a near field communication ( NFC) network and other one or a combination of them. In some embodiments, the network 120 may include one or more network access points. For example, the network 120 may include wired and/or wireless network access points, such as base stations and/or Internet exchange points, through which one or more components of the radiotherapy system 100 may be connected to the network 120 to exchange data and /Or information.

The terminal 130 may include a mobile device 131, a tablet computer 132, a notebook computer 133, etc., or any combination thereof. In some embodiments, the mobile device 131 may include a smart home device, a wearable device, a mobile device, a virtual reality device, an augmented reality device, etc., or any combination thereof. In some embodiments, the smart home device may include a smart lighting device, a smart electrical appliance control device, a smart monitoring device, a smart TV, a smart camera, a walkie-talkie, etc. or any combination thereof. In some embodiments, the wearable device may include bracelets, footwear, glasses, helmets, watches, clothes, backpacks, smart accessories, etc., or any combination thereof. In some embodiments, the mobile device may include a mobile phone, a personal digital assistant (PDA), a game device, a navigation device, a POS device, a notebook computer, a tablet computer, a desktop computer, etc., or any combination thereof. In some embodiments, the virtual reality device and/or augmented reality device may include a virtual reality helmet, virtual reality glasses, virtual reality patch, augmented reality helmet, augmented reality glasses, augmented reality patch, etc. or any combination thereof. For example, the virtual reality device and/or augmented reality device may include Google Glass ^(TM) , Oculus Rift ^(TM) , HoloLens ^(TM) or Gear VR ^(TM), etc. In some embodiments, the terminal 130 may be part of the processing engine 140.

The processing device 140 may process data and/or information obtained from the radiotherapy device 110, the terminal 130, and/or the storage device 150. For example, the processing device 140 may process treatment plan data and determine motion parameters for controlling the movement of multiple components of the radiotherapy device 110. Before treatment, the processing device 140 may match the imaged beam image with the planning data to correct the isocenter of the treatment device 110. The processing device 140 may also determine a reasonable tolerance value for the difference in the treatment beam dose according to the simulated experimental data, and monitor the actual treatment beam dose according to the tolerance value. In some embodiments, the processing device 140 may be a single server or a group of servers. The server group can be centralized or distributed. In some embodiments, the processing device 140 may be local or remote. For example, the processing device 140 may access information and/or data from the radiotherapy device 110, the terminal 130, and/or the storage device 150 through the network 120. For another example, the processing device 140 may be directly connected to the radiotherapy device 110, the terminal 130, and/or the storage device 150 to access information and/or data. In some embodiments, the processing device 140 may be integrated in the radiotherapy device 110. In some embodiments, the processing device 140 may be implemented on a cloud platform. For example, cloud platforms can include one or a combination of private clouds, public clouds, hybrid clouds, community clouds, distributed clouds, cross-clouds, and multi-clouds. In some embodiments, the processing device 140 may be implemented by the computing device 200 having one or more components described in FIG. 2.

The storage device 150 may store data, instructions, and/or any other information. In some embodiments, the storage device 150 may store data obtained from the processing device 140 and/or the terminal 130. For example, data such as treatment plan data, imaging outgoing beam projection image, reference image, tolerance value and so on. In some embodiments, the storage device 150 may store data and/or instructions that can be executed or used by the processing device 140 to perform the exemplary methods described in this application. In some embodiments, the storage device 150 may include one or a combination of a mass memory, a removable memory, a volatile read-write memory, a read-only memory (ROM), etc. Mass storage can include magnetic disks, optical disks, solid state drives, and mobile storage. Removable storage may include flash drives, floppy disks, optical disks, memory cards, ZIP disks, tapes, etc. Volatile read-write memory may include random access memory (RAM). RAM can include dynamic random access memory (DRAM), double data rate synchronous dynamic random access memory (DDR-SDRAM), static random access memory (SRAM), thyristor random access memory (T-RAM), zero capacitance random access memory Access memory (Z-RAM), etc. ROM can include mask read-only memory (MROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), optical disk read-only memory Storage (CD-ROM), digital versatile disc, etc. In some embodiments, the storage device 150 may be implemented by the cloud platform described in this application. For example, a cloud platform may include one or a combination of private clouds, public clouds, hybrid clouds, community clouds, distributed clouds, cross-clouds, and multi-clouds.

In some embodiments, the storage device 150 may be connected to the network 120 to implement communication with one or more components (for example, the processing device 140, the terminal 130, etc.) in the radiotherapy system 100. One or more components in the radiotherapy system 100 can read data or instructions in the storage device 150 via the network 120. In some embodiments, the storage device 150 may be part of the processing device 140.

FIG. 2 is an exemplary schematic diagram of hardware and/or software components of an exemplary computing device 200 that can implement the processing device 140 according to some embodiments of the present invention. As shown in FIG. 2, the computing device 200 may include a processor 210, a memory 220, an input/output (I/O) 230, and a communication port 240.

The processor 210 may execute computer instructions (for example, program code) and may perform the functions of the processing device 140 according to the technology described in the application. The computer instructions may be used to perform specific functions described in this application, and the computer instructions may include, for example, programs, objects, components, data structures, programs, modules, and functions. For example, the processor 210 may process planning data obtained from the storage device 150 and/or any other components of the radiation therapy system 100. In some embodiments, the processor 210 may include one or more hardware processors, such as a microcontroller, a microprocessor, a reduced instruction set computer (RISC), and an application specific integrated circuit (application specific integrated circuit). circuit (ASIC)), application-specific instruction-set processor (ASIP), central processing unit (CPU), graphics processing unit (GPU)) , Physical processing unit (physics processing unit (PPU)), digital signal processor (digital signal processor (DSP)), field programmable gate array (FPGA)), advanced RISC machine (advanced RISC machine( ARM)), programmable logic device (PLD), any circuit or processor capable of performing one or more functions, or a combination of several of them.

For illustration only, only one processor is described in the computing device 200. However, it should be noted that the computing device 200 may also include multiple processors. The operations and/or methods performed by one processor described in this application may also be performed by multiple processors together or separately. For example, if the processor of the computing device 200 described in this application performs operation A and operation B, it should be understood that operation A and operation B can also be performed by two or more different processors in 200 in the computing device. Performed jointly or separately (for example, the first processor performs operation A and the second processor performs operation B, or the first processor and the second processor perform operations A and B together).

The memory 220 may store data/information acquired from the radiotherapy device 110, the terminal 130, the storage device 150, and/or any other components of the radiotherapy system 100. In some embodiments, the memory 220 may include one or a combination of a mass memory, a removable memory, a volatile read-write memory, a read-only memory (ROM), etc. Mass storage can include magnetic disks, optical disks, solid state drives, and mobile storage. Removable storage may include flash drives, floppy disks, optical disks, memory cards, ZIP disks, tapes, etc. Volatile read-write memory may include random access memory (RAM). RAM can include dynamic random access memory (DRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), static random access memory (SRAM), thyristor random access memory (t-ram), zero capacitance random access memory Take memory (Z-RAM) and so on. ROM can include mask read-only memory (MROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), optical disk read-only memory Storage (CD-ROM), digital versatile disc, etc. In some embodiments, the memory 220 may store one or more programs and/or instructions for executing the exemplary methods described in this application. For example, the storage 220 may store a program, and the program may be used for the processing device 140 to determine the motion parameters of multiple components.

The input/output 230 may input and/or output signals, data, information, etc. In some embodiments, the input/output 230 may implement interaction between the user and the processing device 140. In some embodiments, the input/output 230 may include an input device and an output device. The input device may include one or a combination of a keyboard, a mouse, a touch screen, and a microphone. The output device may include one or a combination of a display device, a speaker, a printer, a projector, etc. The display device may include one or a combination of a liquid crystal display (LCD), a light emitting diode (LED) display, a flat panel display, a curved screen, a television device, a cathode ray tube (CRT), a touch screen, etc.

The communication port 240 may be connected to a network (for example, the network 120) to facilitate data communication. The communication port 240 may establish a connection between the processing device 140 and the radiotherapy device 110, the terminal 130, and/or the storage device 150. The connection may be a wired connection, a wireless connection, any connection capable of data transmission and/or reception, or a combination of several of them. The wired connection may include, for example, one or a combination of several of cables, optical cables, and telephone lines. The wireless connection may include, for example, one or more of Bluetooth ^TM link, Wi-Fi ^TM link, WiMAX ^TM link, wireless local area network link, ZigBee ^TM link, mobile network link (for example, 3G, 4G, 5G, etc.) Kind of combination. In some embodiments, the communication port 240 may be and/or include a standardized communication port, such as RS232, RS485, and so on. In some embodiments, the communication port 240 may be a specially designed communication port. For example, the communication port 240 may be designed according to digital imaging and communication in the DICOM protocol.

Fig. 3 is a block diagram of a radiation therapy beam monitoring system according to some embodiments of the present application. As shown in FIG. 3, the radiation therapy beam monitoring system may include an acquisition module 310, a judgment module 320, an execution module 330, and a reference image determination module 340.

The acquiring module 310 may be used to acquire real-time treatment beam images. In some embodiments, the real-time treatment beam image may be generated based on the beam obtained by the treatment incident beam passing through the radiation object in the current radiotherapy process. In some embodiments, the treatment incident beam may pass through one or more collimators having a specific shape to form a beam of rays with a cross-sectional shape smaller than or equal to the shape of the patient's tumor. In some embodiments, the treatment device may include an imaging component, and the imaging component may receive the outgoing beam of the treatment incident beam passing through the radiation object to form a treatment outgoing beam projection image. In some embodiments, the imaging component can acquire a projection image of the treatment exit beam at a certain frequency. In some embodiments, the acquisition module 310 is used to acquire a reference reference image. The reference reference image may be determined based on an imaging outgoing beam image, and the imaging outgoing beam image is generated based on an outgoing beam obtained by an imaging incident beam passing through a radiation object. In some embodiments, the reference reference image may be determined based on the first imaged beam image, which is beneficial to monitor the change of the beam dose based on the reference reference image when the patient's own weight or tissue changes. In some embodiments, the imaging outgoing beam image may be an outgoing beam projection image obtained by imaging the incident beam through the radiation object. In some embodiments, the imaging incident beam and the therapeutic incident beam of radiotherapy are beams of the same energy level. For example, both beams are beams with megavolt energy. In some embodiments, the imaging incident beam and the treatment incident beam are from the same radiation source. For example, the imaging incident beam and the therapeutic incident beam are generated by the same accelerator. In some embodiments, the imaging incident beam and the therapeutic incident beam may be beams with the same energy spectrum. For example, the imaging incident beam and the treatment incident beam can come from different ray sources. The imaging and treatment incident beams can be beam-matched first, so that the imaging incident beam and the treatment incident beam are adjusted to have the same energy spectrum. Beam. In some embodiments, the same energy spectrum can be understood to mean that within a certain range, the beam energy spectrum curves of the imaging incident beam and the therapeutic incident beam are basically the same. In some embodiments, the imaging beam image is acquired before radiotherapy. In some embodiments, the imaged outgoing beam image is an image used for image guidance of user positioning before radiotherapy. In some embodiments, the imaging CT scan may be a CBCT (Cone Beam Computed Tomography, cone beam computed tomography) scan to obtain a two-dimensional imaging beam image. In some embodiments, multiple imaging beam images can be obtained at multiple projection angles, and the imaging beam images at multiple angles can be simulated and reconstructed to obtain a tomographic image, which is then aligned with the planned CT image.

The determining module 320 may be configured to determine whether the pixel value difference between the real-time treatment beam image and the reference reference image meets a preset condition. In some embodiments, the pixel value ratio of the corresponding pixel points of the real-time treatment beam image and the reference reference image may be determined based on the real-time treatment beam image. Since the imaging beam and the treatment beam are rays of the same energy level, only the dose rate of the imaging beam and the dose rate of the treatment beam are different. In an ideal situation, the pixel ratio of the imaging beam image and the treatment beam image should be constant. And in theory, the ratio should be the ratio of the imaging dose rate to the dose rate of the treatment plan. Based on this principle, based on the first imaging beam image to establish a reference reference image, the treatment beam can be monitored. In some embodiments, it may be determined whether the pixel value difference is within a tolerance range based on the pixel value ratio. In some embodiments, the tolerance range is a reasonable fluctuation range of a ratio determined based on a combination of one or more of signal-to-noise ratio, output factor, penumbra position, non-uniform ray influence, or equipment stability factor. In some embodiments, the signal-to-noise ratio is the ratio of the outgoing beam dose signal to noise, and the difference in imaging and treatment field doses can directly lead to fluctuations in the pixel ratio of the treatment outgoing beam image and the imaging outgoing beam image. In some embodiments, the output factor is the relationship between the absorbed dose at a certain point on the central axis of the beam in the body and the size of the radiation field. However, the size of the field size of the treatment plan and the size of the imaging field are different, and the output factor is different, which causes the fluctuation of the pixel value ratio to increase. In some embodiments, the boundary of the treatment field is generally smaller than or equal to the shape of the tumor, and the edge of the treatment field usually needs to be covered by multiple gratings to form a precise irregular boundary. Due to other factors such as the radiation source and the collimation system, the boundary of the treatment field will be very blurred, forming a certain proportion of the penumbra position area on the boundary. In the penumbra position area, the pixel ratio of the treatment beam image and the imaging beam image is difficult to be a constant, and there is a large dose error. In some embodiments, the radiation in the radiation field is usually non-uniform, and the non-uniformity of the radiation may cause dose errors. For example, the deviation of the treatment isocenter will cause the peak dose to move, resulting in dose error. In some embodiments, the equipment stability factors may include the equipment itself factors such as control accuracy, equipment operating conditions, and proper maintenance. In some embodiments, a simulation experiment may be performed based on the phantom to obtain the simulated ratio of the treatment beam image and the reference image. In some embodiments, the tolerance range may be determined based on the analog ratio. In some embodiments, a simulation phantom can be used to perform simulation experiments according to the treatment plan. The phantom can be a simulation phantom of the human body of various ages and various parts of the human body. In some embodiments, different phantoms may be used to repeatedly perform simulation experiments to obtain simulation ratios of multiple treatment beam images and reference reference images, and compare multiple simulation ratios to determine a tolerance range.

The execution module 330 can be used to control the radiotherapy process based on the judgment result. In some embodiments, when the pixel value difference between the real-time treatment beam image and the reference reference image exceeds the tolerance range, the current treatment is stopped. In some embodiments, equipment aging, equipment failure, radiotherapy system errors, changes in the patient’s weight, tissue changes, changes in the patient’s breathing or other human activities during treatment, or changes in the patient’s long-term treatment One or a combination of several conditions, such as body deviation, will cause the treatment beam dose error to become larger, which exceeds the tolerance range. If the ratio of the pixel value between the real-time treatment beam image and the reference image exceeds the tolerance range, the treatment beam may not meet the requirements of the plan, and the dose distribution of the treatment beam may seriously deviate from the planned position, which will affect the tissue in the non-tumor area. Or damage to the organ. Or the dose rate of the radiation does not meet the plan requirements, which affects the treatment effect. At this time, radiotherapy can be stopped, and the factors that cause the difference to exceed the tolerance range can be determined or eliminated, thereby ensuring the effect of radiotherapy and avoiding unnecessary damage to the patient.

The reference reference image determining module 340 may be used to perform position coordinate correction on the imaged outgoing beam image to obtain an initial reference reference image. In some embodiments, the imaging isocenter position and the isocenter position of the treatment plan may be acquired, and the position coordinate correction of the imaging beam image is performed based on the difference between the imaging isocenter position and the treatment plan isocenter position . In some embodiments, before each treatment, multiple angle imaging MV-CBCT scans can be performed on the patient, and a three-dimensional imaging image can be reconstructed from the multiple angle imaging beam images. In some embodiments, the three-dimensional imaging image can be compared with the planned three-dimensional CT image reflecting the positioning of the anatomical structure to determine the three-dimensional position offset between the imaging isocenter and the planned isocenter in the current three-dimensional space. The displacement in the opposite direction of the offset is the three-dimensional correction of the imaging isocenter. In some embodiments, the three-dimensional correction amount between the imaging isocenter and the planned isocenter can be converted into a two-dimensional correction amount, and the position of the two-dimensional MV-CBCT imaging beam image is corrected to make the beam image be imaged Match the position of the planned anatomical structure image to get the initial reference image.

In some embodiments, the reference reference image determining module 340 may be used to perform collimator rotation angle correction on the initial reference reference image. In some embodiments, the angle of the collimator during imaging and the angle of the collimator of the treatment plan can be acquired, and the angle difference between the angle of the collimator during imaging and the angle of the collimator of the treatment plan can be determined, based on the The angle difference corrects the position coordinate of the imaging beam image. For example, the angle value of the collimator in the treatment plan can be obtained, and the boundary range and the shape of the boundary of the initial imaging beam image can be determined according to the planned collimator angle to obtain the initial reference reference image. In some embodiments, the mask image may be rotated according to the planned collimator angle, and the mask image and the initial reference reference image may be subjected to a pixel AND operation to obtain the reference reference image after the boundary is rotated.

In some embodiments, the reference reference image determining module 340 may be used to perform position matching on the initial reference reference image based on the treatment field, to obtain an area corresponding to the treatment field in the initial reference reference image, and to determine the area as the target area. The reference reference image. In some embodiments, the position and boundary range of the planned treatment field can be simulated and reconstructed according to the position of the multi-leaf grating (MLC) in the treatment plan to generate a mask image. In some embodiments, the mask image and the initial reference image may be calculated to obtain the corresponding area. In some embodiments, the pixel value of the area corresponding to the treatment field in the mask image may be set to 1, and the pixel value of the area outside the treatment field may be set to 0. The mask image and the initial reference reference image corrected by the position coordinates are subjected to pixel sum calculation, and the area corresponding to the treatment field in the initial reference reference image is extracted to obtain the reference reference image. In some embodiments, at least one treatment beam image may be acquired, boundary information of the actual treatment field may be determined based on the treatment beam image, and the mask image may be verified based on the boundary information. In the actual treatment process, the actual leaf position of the multi-leaf grating will deviate from the setting value in the treatment plan. In order to avoid the error of the actual position and the setting value from affecting the accuracy of the reference reference image, you can The actual boundary data of the multi-leaf grating verifies the mask image to obtain a reference image more in line with the treatment situation. In some embodiments, at least one treatment beam image can be acquired during treatment, Hough Transform is performed on the treatment beam image, the actual blade position is determined, and the actual grating position is verified based on the grating position in the treatment plan Whether the exercise is in place according to the treatment plan.

It should be understood that the system and its modules shown in FIG. 3 can be implemented in various ways. For example, in some embodiments, the system and its modules may be implemented by hardware, software, or a combination of software and hardware. Among them, the hardware part can be implemented using dedicated logic; the software part can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. Those skilled in the art can understand that the above-mentioned methods and systems can be implemented using computer-executable instructions and/or included in processor control codes, for example on a carrier medium such as a disk, CD or DVD-ROM, such as a read-only memory (firmware Such codes are provided on a programmable memory or a data carrier such as an optical or electronic signal carrier. The system and its modules of this application can not only be implemented by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, etc., or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc. It can also be implemented by software executed by various types of processors, or can be implemented by a combination of the aforementioned hardware circuit and software (for example, firmware).

It should be noted that the above description of the candidate item display and determination system and its modules is only for convenience of description, and does not limit the present application within the scope of the cited embodiments. It can be understood that for those skilled in the art, after understanding the principle of the system, it is possible to arbitrarily combine various modules, or form a subsystem to connect with other modules without departing from this principle. For example, in some embodiments, for example, the acquisition module 310, the judgment module 320, the execution module 330, and the reference reference image determination module 340 disclosed in FIG. 3 may be different modules in a system, or may be a module to implement the above The function of two or more modules. For example, the judgment module 320 and the reference reference image determination module 340 may be two modules, or one module may have both sending and receiving functions. For example, each module may share a storage module, and each module may also have its own storage module. Such deformations are all within the protection scope of this application.

Fig. 4A is an exemplary flowchart of a method for determining a reference reference image according to some embodiments of the present application. The process 400 may be executed by processing logic, which may include hardware (for example, circuits, dedicated logic, programmable logic, microcode, etc.), software (instructions running on a processing device to execute hardware simulation), etc., or any of them combination.

Step 410: Perform position coordinate correction on the imaged outgoing beam image to obtain an initial reference reference image. In some embodiments, step 410 may be performed by the reference image determination module 340. In some embodiments, the imaging outgoing beam image may be an outgoing beam projection image obtained by imaging the incident beam through the radiation object. In some embodiments, the imaged outgoing beam image may be corrected in position coordinates according to the treatment plan.

In some embodiments, the radiotherapy equipment can be used to image the patient to obtain the imaged beam image before radiotherapy. Among them, the imaging incident beam and the treatment incident beam can be beams of the same energy level. In some embodiments, the treatment incident beam may be a megavolt incident beam, and the imaging incident beam may also be a megavolt incident beam. For example, the energy of the imaging incident beam may be 6MV, and the energy of the treatment incident beam may be 6MV. In some embodiments, the imaging incident beam may be from the same radiation source as the therapeutic incident beam. For example, the imaging incident beam and the therapeutic incident beam are generated by the same accelerator. In some embodiments, the imaging incident beam and the therapeutic incident beam are beams with the same energy spectrum. For example, the imaging incident beam and the therapeutic incident beam can originate from different radiation sources. The imaging and therapeutic incident beams can be beam-matched first, so that the imaging incident beam and the therapeutic incident beam have the same energy spectrum. bundle. In some embodiments, both the imaging incident beam and the treatment incident beam are megavolt beams, generated by the same accelerator in the radiotherapy equipment, and the imaging beam image is a MV-CBCT (Megavolt CBCT) reconstruction front plane projection image . The imaging incident beam and the treatment incident beam are beams of the same energy level. A reference reference image can be established based on the imaging beam image, and the reference reference image is used to monitor whether the dose distribution of the actual treatment beam meets the plan requirements. The reference image can be obtained in a simplified and accurate manner, and the accuracy of radiotherapy can be improved. At the same time, a beam of the same energy level as the treatment incident beam can be used to integrate the imaging incident beam dose and the radiotherapy dose, and the imaging dose is included in the treatment dose to avoid additional risk burden for the patient.

In some embodiments, a planned CT (Computed Tomography, computer tomography) scan may be performed on the patient before radiotherapy to obtain an image of the patient's anatomy (or called a localized CT image). In some implementations, a planned CT scan can also be performed on the phantom that simulates the patient to obtain an image of the patient's anatomy. Through the anatomical structure images, the patient's dose distribution is simulated and calculated and the radiotherapy plan is designed to determine the patient's treatment plan. In some embodiments, the treatment plan may include a patient's anatomical structure image (or referred to as a localized CT image), a dose distribution determined according to the anatomical structure image, and treatment plan parameters. In some embodiments, the treatment plan parameters may include one or a combination of data such as the isocenter position of the treatment plan, the collimator angle of the treatment plan, and the position data of the grating. In some embodiments, the collimator angle may be the rotation angle of the collimator to change the direction of movement of the multi-leaf grating. The collimator angle and the position of the multi-leaf grating are adjusted together to form the desired field shape and shield the Tumor area rays. In some embodiments, the localized CT image may be obtained by scanning the radiation target with a kilovolt energy beam, for example, by scanning the radiation target with a CT device. In some embodiments, the positioning CT image may be a three-dimensional tomographic anatomical structure image.

In some embodiments, the position coordinate correction may be performed on the imaged beam image based on the positioning CT image in the treatment plan. In some embodiments, before radiotherapy, a radiotherapy device is used to perform a multi-angle imaging scan on the patient, wherein the imaging scan beam is a megavolt energy level beam, which is the same energy level as the treatment beam, and further, imaging The scanning beam and the treatment beam can be from the same radiation source, or the imaging scanning beam and the treatment beam can be the same energy spectrum radiation source. Perform three-dimensional reconstruction of the projection data obtained from the scan to obtain a three-dimensional treatment guidance image. Match the three-dimensional guidance treatment image with the positioning CT image to obtain the X direction (patient left and right direction), Y direction (patient dorsal and abdominal direction), Z Position error in the direction (the direction of the patient’s toe). In some embodiments, the imaging CT scan may be a CBCT (Cone Beam Computed Tomography, Cone Beam Computed Tomography) scan, which may obtain a series of two-dimensional imaging beam images.

In some embodiments, the initial reference reference image may be obtained based on the projection image of the imaging beam at the same energy level as the treatment beam after the position coordinate is corrected. In some embodiments, the position coordinate correction may include isocenter correction. As shown in FIG. 1, the central axis of the treatment head 112 and the rotation axis of the gantry 113 intersect at a point, which is called an isocenter. In some embodiments, the isocenter position of the imaging and the isocenter position of the treatment plan can be acquired. In some embodiments, before each treatment, multiple angle imaging MV-CBCT scans can be performed on the patient, and the guided treatment image can be reconstructed based on the multiple angle imaging beam images. In some embodiments, the positioning CT images in the treatment plan can be obtained from the radiotherapy device 110, the network 120, the terminal 130, the storage device 150, or any device or component capable of storing data disclosed in this application. In some embodiments, the three-dimensional imaging image can be compared with the planned three-dimensional anatomical structure image to obtain the imaging isocenter position and the treatment plan isocenter position, and determine the three-dimensional space between the imaging isocenter and the planned isocenter in the three-dimensional space. The position offset, the displacement in the opposite direction of the three-dimensional position offset is the three-dimensional correction amount of the imaging isocenter. As shown in Figure 5, X'Y'Z' is the three-dimensional anatomical structure image of the treatment plan, O'is the isocenter of the three-dimensional anatomical structure image of the treatment plan, XYZ is the three-dimensional imaging image, and O is the isocenter of the three-dimensional imaging image. Match the anatomical structures in the two three-dimensional images, determine the offsets of O'and O in the X, Y, and Z directions, and the movement in the opposite direction is the three-dimensional correction between the imaging isocenter and the planned isocenter.

In some embodiments, the three-dimensional correction amount between the imaging isocenter and the planned isocenter can be converted into a two-dimensional correction amount, and the position of the two-dimensional MV-CBCT imaging beam image is corrected to make the beam image be imaged Match the position of the planned anatomical structure image to get the initial reference image. In some embodiments, when the gantry angle is 0° (the ray source is at 12 o'clock on the gantry) or 180° (the ray source is at 6 o'clock on the gantry), the Y direction may be the patient’s dorsal and abdominal direction. The correction amount in the Y direction is an adjustment value of the height between the patient and the radiation source, and the correction value in the Y direction can be converted into a proportional enlargement or reduction value of the two-dimensional image for correction. The X direction can be the patient's left and right direction, the Z direction can be the patient's head and foot direction, the correction amount in the X and Z directions is the translation amount of the worktable 160 on the XOZ plane, which can be based on the correction amount in the X and Z directions It is converted into a two-dimensional imaging beam image for correction by corresponding translational components in the X and Z directions. For example, when the gantry angle is 0° (the ray source is at 12 o'clock on the gantry), imaging projection is performed to obtain a 0° imaging beam image. The obtained three-dimensional correction amount can be converted into the correction amount of the 0° two-dimensional imaging projection image. The correction value in the Y direction is the proportional enlargement or reduction value of the 0° two-dimensional imaging projection image. The translational components of the two-dimensional imaging projection image with the correction amount of 0° in the X and Z directions in the X and Z directions, respectively. For another example, as shown in Figure 6, the ray source rotates in the XOY plane with O as the center. When the gantry angle is +30° (the ray source is at the 12 o'clock position on the gantry and the angle is 30° to the left), imaging is performed. The correction amount in the middle center of the three-dimensional coordinate system is (x, y, z), where y has a component ycos30° on Y′, and the two-dimensional imaging beam image is scaled up or down according to ycos30°. x has a component xcos30° on the ZOX′ plane, and according to xcos30°, z translates the imaged outgoing beam image.

In some embodiments, the position coordinate correction may include collimator rotation angle correction. Normally, when performing imaging scanning, the imaging collimator angle is set to 0°. In the actual treatment process, the collimator needs to be set with a certain rotation angle according to the shape and size of the tumor to obtain a more ideal dose distribution. To establish a reference reference image based on the imaging beam image, the initial imaging beam image needs to be corrected by the collimator angle according to the treatment requirements to match the treatment plan and achieve the purpose of accurately monitoring the treatment beam. In some embodiments, the angle value of the collimator in the treatment plan may be obtained, and the boundary range and the boundary angle of the initial reference reference image can be determined according to the planned collimator angle. In some embodiments, the mask image may be rotated according to the planned collimator angle, and the mask image and the initial reference reference image may be subjected to a pixel AND operation to obtain the reference reference image after the boundary is rotated. For example, as shown in Figure 7, if the collimator angle is θ in the treatment plan, the mask image can be rotated clockwise or counterclockwise on the XOZ plane by taking the isocenter as the center of rotation to make the mask image and The treatment plan is matched, and the rotated mask image and the initial reference reference image are ANDed to obtain the reference reference image corrected by the collimator angle (the boundary is the field of view of the solid line).

Step 420: Perform position matching on the initial reference reference image based on the treatment field, obtain an area corresponding to the treatment field in the initial reference reference image, and determine the area as the reference reference image.

In some embodiments, the treatment field is the field range of the emitted beam during actual treatment. The treatment field is much smaller than the imaging field. In order to protect the tissues and organs in the non-tumor area, the radiotherapy beam will pass through the multi-leaf grating. The multi-leaf grating will block the excess beam and avoid the non-tumor area tissues from being damaged by the radiotherapy beam. , The general treatment field is less than or equal to the area of the tumor. The position of each grating in the multi-leaf grating is adjustable, so that a space matching the treatment area is formed between the multiple gratings, which facilitates the passage of the treatment beam. To establish a reference reference image, it is necessary to determine the area corresponding to the treatment field in the imaging beam image, and segment this area as the reference reference image.

In some embodiments, the position and boundary range of the planned treatment field can be simulated and reconstructed according to the position of the multi-leaf grating (MLC) in the treatment plan to generate a mask image. In some embodiments, the mask image and the initial reference image may be calculated to obtain the corresponding area. In some embodiments, the pixel value of the area corresponding to the treatment field in the mask image may be set to 1, and the pixel value of the area outside the treatment field may be set to 0. The mask image and the initial reference reference image corrected by the position coordinates are subjected to pixel sum calculation, and the area corresponding to the treatment field in the initial reference reference image is extracted to obtain the reference reference image.

In some embodiments, the actual leaf position of the multi-leaf grating in the actual treatment process may deviate from the theoretical setting value. In order to prevent the error of the actual position and the setting value from affecting the accuracy of the reference image, the actual treatment In the process, the mask image is verified according to the actual boundary data of the multi-leaf grating to obtain a reference image more in line with the treatment situation. In some embodiments, at least one treatment beam image can be acquired during treatment, Hough Transform is performed on the treatment beam image, the actual blade position is determined, and the actual grating position is verified based on the grating position in the treatment plan Whether the exercise is in place according to the treatment plan.

In some embodiments, in order to protect the tissues and organs in the non-tumor area and prevent the tissue in the non-tumor area from being damaged by the radiation beam, the treatment field needs to be able to match various irregularly shaped tumors. Therefore, the edge of the treatment field usually needs multiple gratings to cover to form a precise irregular boundary. Usually the radiation source, collimation system and other factors cause the edge of the treatment field to be affected by penumbra to varying degrees, resulting in blurred boundaries. In order to eliminate the penumbra effect as much as possible, it is necessary to eliminate the field boundary area where the penumbra has a serious effect in the mask image to improve the edge accuracy of the mask image, thereby obtaining a more accurate reference image and reducing The influence of the penumbra area on the treatment beam monitoring. In some embodiments, the area where the penumbra of the treatment field boundary is more severely affected can be eliminated through the open operation. To open an operation is to corrode and then expand. Corrosion is a process of eliminating boundary points and shrinking the boundary to the interior of the region. It can be used to eliminate the tiny boundary regions that are susceptible to penumbra. Expansion is the process of merging all the background points in contact with the object into the object and expanding the boundary to the outside of the area. It can be used to fill the void in the eliminated area of the boundary area. In some embodiments, the mask image and the initial reference reference image after correction by the opening operation are subjected to a pixel sum calculation to obtain the reference reference image.

Fig. 4B is an exemplary flowchart of another method for determining a reference reference image according to some embodiments of the present application. The process 500 may be executed by processing logic, which may include hardware (for example, circuits, dedicated logic, programmable logic, microcode, etc.), software (instructions running on a processing device to execute hardware simulation), etc., or any of them combination.

In step 510, the digital reconstruction image (DRR) of the planned CT image may be determined first. In some embodiments, the planned CT image is a CT scan image used to determine a treatment plan before treatment. As described above, an image of the patient's anatomy (or called a localized CT image) can be obtained. In some embodiments, the digitally reconstructed image of the planned CT image may be a two-dimensional projection image reconstructed from the three-dimensional tomographic image of the planned CT. In some embodiments, a plurality of projection data may be calculated according to S ₀ *exp (-μL), and the digital reconstruction image of the planned CT image may be determined based on the plurality of projection data. Among them, S ₀ is the empty scan signal minus the background value, the empty scan signal is the signal collected by the detector when the rays are only attenuated in the air, and the background value is the environmental signal collected by the detector when the radioactive source is not working. L is the length in the human body in the linear distance between the detector and the planned CT radiation source. In some embodiments, the linear distance between the detector and the planned CT radiation source may be the linear distance between the detection unit in the middle position on the detector and the radiation source. μ is the average attenuation coefficient of rays passing through the human body from one direction. In some embodiments, the attenuation coefficient μ can be calculated from CT pixel values. In some embodiments, the attenuation coefficient may be the average of the attenuation coefficients of all pixels through which the radiation passes through the human body.

In step 520, an initial reference reference image may be obtained based on the digitally reconstructed image of the planned CT image and the imaged beam image. In some embodiments, the digital reconstructed image of the planned CT and the imaging beam image may be deformed and registered based on an image registration algorithm to obtain the initial reference reference image.

In some embodiments, MVCBCT projection images can be acquired. In some embodiments, the MVCBCT projection image may be an emergent beam projection image obtained by imaging the incident beam through the radiation object. In some embodiments, the radiotherapy equipment may be used to image the patient before the first radiotherapy to obtain an imaged beam image. Among them, the imaging incident beam and the treatment incident beam can be beams of the same energy level. For example, the treatment incident beam may be a megavolt incident beam, and the imaging incident beam may also be a megavolt incident beam. In some embodiments, the imaging incident beam may be from the same radiation source as the therapeutic incident beam. For example, the imaging incident beam and the therapeutic incident beam are generated by the same accelerator. In some embodiments, the imaging incident beam and the therapeutic incident beam are beams with the same energy spectrum. For example, the imaging incident beam and the therapeutic incident beam can originate from different radiation sources. The imaging and therapeutic incident beams can be beam-matched first, so that the imaging incident beam and the therapeutic incident beam have the same energy spectrum. bundle. In some embodiments, both the imaging incident beam and the treatment incident beam are megavolt beams, generated by the same accelerator in the radiotherapy equipment, and the imaging beam image is a MV-CBCT (Megavolt CBCT) reconstruction front plane projection image . The imaging incident beam and the treatment incident beam are beams of the same energy level. A reference reference image can be established based on the imaging beam image, and the reference reference image is used to monitor whether the dose distribution of the actual treatment beam meets the plan requirements. The reference image can be obtained in a simplified and accurate manner, and the accuracy of radiotherapy can be improved. At the same time, a beam of the same energy level as the treatment incident beam can be used to integrate the imaging incident beam dose and the radiotherapy dose, and the imaging dose is included in the treatment dose to avoid additional risk burden for the patient.

In some embodiments, the registration algorithm may include one or a combination of methods such as feature point registration algorithm, Demons algorithm, B-spline mutual information algorithm, and finite element analysis. For example, taking the feature point registration algorithm as an example, the imaged beam image can be used as a floating image, and the digital reconstructed image of the planned CT can be used as a reference image. The feature information of the floating image and the reference image can be extracted respectively, such as feature point coordinates, feature The feature information of feature parameters such as point gray value and attenuation coefficient is calculated according to the registration algorithm of feature points to obtain the fusion image of the imaging beam image and the planned CT image. The fused image is used as the initial reference reference image. The initial reference reference image established by the method of this embodiment can convert the planned CT image of the kilovolt level into the initial reference reference image of the megavolt level, and retain the most original and basic anatomical structure information and attenuation information to the greatest extent, so that The monitoring of subsequent treatment beams is more accurate.

Step 530: Perform position matching on the initial reference reference image based on the treatment field, obtain an area corresponding to the treatment field in the initial reference reference image, and determine the area as the reference reference image. Step 530 is the same as step 420 in the process 400. For specific implementation, please refer to the relevant description of step 420.

Fig. 8 is an exemplary flowchart of a method for determining a tolerance according to some embodiments of the present application. The process 800 may be executed by processing logic, which may include hardware (for example, circuits, dedicated logic, programmable logic, microcode, etc.), software (instructions running on a processing device to execute hardware simulation), etc., or any of them combination.

In step 810, a simulation experiment may be performed based on the treatment plan to obtain a simulation ratio between the treatment beam image and the reference image. In some embodiments, step 810 may be performed by the judgment module 320. If the imaging beam and the treatment beam are rays of the same energy level, only the dose rate of the imaging beam and the dose rate of the treatment beam are different. The difference in dose rate can be embodied in the different pixel values of the outgoing beam image. Therefore, the ratio of the pixel values of the imaging beam image and the treatment beam image is approximately the ratio of the dose rate of the imaging beam and the treatment beam in the same area (after correcting the detector dose rate response). Therefore, under ideal circumstances, the pixel ratio of the imaging beam image and the treatment beam image on the same area should be constant. And in theory, the ratio should be the ratio of the imaging dose rate to the dose rate of the treatment plan. Based on this principle, a reference reference image is established based on the imaging beam image, and the treatment beam can be monitored. If the pixel ratio between the treatment beam image and the reference image is close to the theoretical value and fluctuates within a reasonable range, the dose distribution of the treatment beam meets the plan requirements, and the reasonable fluctuation range is the monitoring tolerance. In some embodiments, the factors affecting the tolerance may include one or a combination of several of the signal-to-noise ratio, output factor, penumbra position, non-uniform ray influence, or equipment stability factors. In some embodiments, the signal-to-noise ratio is the ratio of the outgoing beam dose signal to noise, and the difference between the imaging dose and the treatment dose can directly lead to a difference in the pixel ratio between the treatment outgoing beam image and the imaging outgoing beam image. In some embodiments, the output factor is the relationship between the absorbed dose at a certain point on the central axis of the beam in the body and the size of the radiation field. However, the size of the field size of the treatment plan and the size of the imaging field are different, and the output factor is different, which causes the fluctuation of the pixel value ratio to increase. In some embodiments, the boundary of the treatment field is usually smaller than or equal to the shape of the tumor, so the edge of the treatment field usually needs to be covered by multiple gratings to form a precise irregular boundary. The boundary of the treatment field will be very blurred, and there is a certain percentage of the penumbra position area on the boundary. In the penumbra position area, the pixel ratio of the treatment beam image to the imaging beam image is difficult to be a constant, and there is a large error. When determining the mask image, the boundary with a larger penumbra position ratio will be subtracted to reduce the error of the pixel ratio caused by the penumbra position area. However, the existence of the penumbra location area still produces certain systematic errors. In some embodiments, the radiation in the radiation field is usually uneven, the radiation dose rate in the middle position will be relatively high, and the dose rate of the radiation near the edge of the radiation field will be low, with a peak in the middle of the radiation. The non-uniformity of the radiation can cause dose errors. For example, the deviation of the treatment isocenter will cause the peak dose to move, resulting in dose error. In some embodiments, in order to reduce the influence of ray non-uniformity, the air-scan image formed on the two-dimensional detector with the largest field passing through the air can be used as the denominator to remove the imaging beam image and the treatment beam image, respectively, to obtain uniformity The imaged outgoing beam image formed by the radiation and the treatment outgoing beam image formed by the flattening rays, and then the positional coordinate correction of the imaging outgoing beam image formed by the flattening rays is performed to establish a reference reference image, and the treatment outgoing beam image formed by the flattening rays and the reference The reference image is compared to calculate the pixel value to eliminate the influence of uneven rays. In some embodiments, the equipment stability factors may include the equipment itself factors such as control accuracy, equipment operating conditions, and proper maintenance.

In some embodiments, a simulation phantom can be used to perform simulation experiments according to the treatment plan. The phantom can be a simulation phantom of the human body of various ages and various parts of the human body. In some embodiments, the phantom may be a rigid phantom with high repeatability. In some embodiments, different phantoms may be used to repeatedly perform simulation experiments to obtain simulation ratios of multiple treatment beam images and reference reference images, and compare multiple simulation ratios to determine a tolerance range. In some embodiments, the simulation experiment may be to use the phantom to perform simulated treatment in accordance with the treatment plan, obtain the imaging beam image, establish a reference reference image based on the imaging beam image, and compare the obtained treatment beam image with the reference reference image, Get the pixel ratio. Different phantoms can be used for simulated treatment to obtain the pixel ratios of multiple treatment beam images and the reference reference image, and the tolerance is determined according to the fluctuation range of the multiple pixel ratios. It is also possible to use the same phantom to perform multiple simulation treatments, and obtain the pixel ratios of multiple treatment beam images to the reference image to determine the tolerance. In some embodiments, the tolerance is a total tolerance that includes all possible influencing factors that may cause errors. For example, it includes the tolerance under the combined influence of factors such as signal-to-noise ratio, output factor, penumbra position, non-uniform ray influence or equipment stability factors. In some embodiments, it is also possible to artificially change the reasonable fluctuation range of certain factors, so as to obtain multiple corresponding simulation ratios and determine a tolerance range. For example, a simulation experiment can be performed according to the treatment plan when the accelerator is in good condition, and the ideal simulation ratio can be measured and calculated. The beam dose produced by the accelerator usually fluctuates reasonably between -3% and +3%. Artificial simulation can artificially change the accelerator dose, causing the accelerator dose to produce a dose fluctuation of -3% to +3%. The fluctuation simulation ratio is measured and calculated through simulation experiments. If the fluctuation simulation ratio will fluctuate by 5% above and below the ideal simulation ratio, you can Make sure that the tolerance is 6%.

In some embodiments, it is also possible to simulate each factor separately to determine the tolerance corresponding to each factor, and then calculate the tolerance of all factors to determine the total tolerance.

In some embodiments, the relationship between the beam dose and the signal-to-noise ratio can be established, for example, a machine learning model or a functional relationship can be established. Measure the signal-to-noise ratio on the detector, and simulate the ratio of signal to noise measured on the detector when the dose is different to establish the relationship between the dose and the signal-to-noise ratio. According to the planned dose data, the theoretical signal-to-noise ratio can be determined, the fluctuation range of the ratio of the signal-to-noise ratio can be obtained, and the tolerance corresponding to the signal-to-noise ratio factor can be determined.

In some embodiments, the output factor is the ratio of the absorbed dose of any radiation field to the reference radiation field at a given point under the same measurement conditions. It reflects the relationship between the absorbed dose at a certain point on the central axis of the ray beam and the size of the radiation field. However, the size of the radiation field of the treatment plan is different from the size of the imaging radiation field, and the output factor is different, which leads to the error of the dose and the fluctuation of the ratio. In the simulation experiment, it is possible to change the size of the field within a certain range to obtain multiple simulated ratios while ensuring that the shape of the field and the central axis of the incident beam remain unchanged, and determine the difference between the variation of the field size and the fluctuation value of the ratio Relationship. According to the difference between the planned field and the imaging field, the tolerance corresponding to the output factor difference is determined.

In some embodiments, the penumbra position is an area affected by the penumbra that accounts for a certain proportion of the field boundary area. In some embodiments, the ratio of the penumbra position in the boundary area can be changed, the pixel ratio between multiple treatment beam images and the reference image can be simulated, the fluctuation range of the pixel ratio can be determined, and the tolerance corresponding to the penumbra position can be determined . For example, when 50% of the boundary area is the penumbra position, a simulation experiment can be performed to simulate the pixel ratio between the treatment beam image and the reference image. Then increase or decrease the ratio of the penumbra position, perform multiple simulation experiments to obtain multiple pixel ratios, determine the relationship between the ratio of the penumbra position and the fluctuation range of the pixel ratio, according to the ratio of the penumbra position in the boundary area in the plan The data get the tolerance corresponding to the penumbra position.

In some embodiments, the radiation in the radiation field is usually uneven, the radiation dose rate in the middle position will be relatively high, and the dose rate of the radiation near the edge of the radiation field will be low, with a peak in the middle of the radiation. Movement of the isocenter position will cause the peak of the beam to move, resulting in dose errors. In some embodiments, the simulation ratios corresponding to multiple isocenters with different position coordinates can be simulated, and two isocenter simulation data can be selected to determine the ratio fluctuation value produced by the two isocenter displacements, and establish the relationship between the isocenter displacement and the ratio fluctuation value To determine the ratio fluctuation value per unit isocenter displacement. According to the imaging isocenter correction amount, the tolerance corresponding to the ray non-uniformity factor caused by isocenter movement is determined. In some embodiments, the influence of ray non-uniformity on the fluctuation of the pixel value ratio can also be directly reduced. For example, in order to reduce the influence of ray non-uniformity, the air-scan image formed on the two-dimensional detector with the largest field passing through the air can be used as the denominator to remove the imaging beam image and the treatment beam image, respectively, to obtain an image formed by uniform rays The outgoing beam image and the treatment outgoing beam image formed by the flattening rays, and then the imaging outgoing beam image formed by the flattening rays is corrected for position coordinates to establish a reference reference image, and the treatment outgoing beam image formed by the flattening rays is compared with the reference reference image Calculate the pixel value to eliminate the influence of uneven rays.

In step 820, the allowable value range may be determined based on the analog ratio. In some embodiments, step 820 may be performed by the judgment module 320. In some embodiments, the fluctuation range of multiple analog ratios can be determined, and the fluctuation range of the analog ratio is determined as the tolerance. The tolerance can be the total tolerance that includes all possible influencing factors that may cause errors. For example, it includes the tolerance under the combined influence of factors such as signal-to-noise ratio, output factor, penumbra position, non-uniform ray influence or equipment stability factors. In some embodiments, the fluctuation range of multiple simulation ratios can be determined, and a certain relaxation is performed on the basis of the fluctuation range when determining the tolerance. For example, if the analog ratio fluctuates within the range of 5% above and below the center value, the range can be relaxed to 6%, and 6% is set as the tolerance. In some embodiments, the fluctuation range of multiple analog ratios can be determined, and the range can be further reduced on the basis of the fluctuation range when determining the tolerance. For example, in the simulation experiment, multiple simulation ratios obtained under conditions beyond the scope of the treatment plan are simulated, and the fluctuation range of the simulation ratio is determined to be 7%. Then when determining the tolerance, the range can be further reduced on the basis of the fluctuation range of the simulation ratio. 5% is determined as tolerance.

In some embodiments, the single-factor tolerance obtained by simulating each influencing factor separately may be calculated to obtain the final total tolerance. In some embodiments, the tolerances determined by the simulation experiment of multiple individual factors may be weighted to determine the final tolerance. For example, you can set the weight of the tolerance corresponding to the penumbra position to 2, and the weight of the tolerance corresponding to the output factor to 1.5. Multiply the two tolerances by the weights and add them to get the final tolerance. In some embodiments, the tolerance with the largest value among the tolerances corresponding to multiple factors may be used as the total tolerance. For example, if the tolerance corresponding to the output factor is 1.5%, the tolerance corresponding to the penumbra position is 10%, and the tolerance corresponding to the influence of uneven rays is 1%, the tolerance corresponding to the penumbra position can be used as the total tolerance .

Fig. 9 is an exemplary flowchart of a method for monitoring radiation therapy exit beams according to some embodiments of the present application. The process 900 may be executed by processing logic, which may include hardware (for example, circuits, dedicated logic, programmable logic, microcode, etc.), software (instructions running on a processing device to execute hardware simulation), etc., or any of them combination.

In this application, the imaging beam and the treatment beam are rays of the same energy level, but the dose rate of the imaging beam and the dose rate of the treatment beam are different. Therefore, under ideal circumstances, the pixel value of the imaging beam image and the pixel value of the treatment beam image in the same area should be a multiple relationship, and the ratio of the two should be a constant. A reference reference image is established based on the imaging beam image, and the pixel ratio of the treatment beam image to the reference reference image is calculated, and the dose distribution of the treatment beam can be monitored through the pixel ratio.

Step 910: Obtain a reference reference image. Step 910 may be performed by the obtaining module 310. In some embodiments, the reference fiducial image may be determined based on the imaged exit beam image. In some embodiments, the initial reference reference image may be obtained by performing position coordinate correction on the imaged outgoing beam image. In some embodiments, the treatment field may be position-matched with the initial reference reference image to obtain an area corresponding to the treatment field in the initial reference reference image, and this area may be determined as the reference reference image. In some embodiments, the acquisition module may acquire the reference reference image via the network 120, the processing device 140, the terminal 130, and/or the storage device 150.

Step 920 can obtain real-time treatment beam images. In some embodiments, step 920 may be performed by module 310. In some embodiments, the real-time treatment beam image may be generated based on the beam obtained by the treatment incident beam passing through the radiation object in the current radiotherapy process. In some embodiments, the therapeutic incident beam may be generated by a linear accelerator. In some embodiments, the treatment incident beam may be an X-ray beam. In some embodiments, the treatment incident beam can pass through one or more collimators with a specific shape to form a beam with a cross-sectional shape and size that is compatible with the treatment area, such as a beam with a cross-section and a tumor area less than or equal to the patient's tumor. bundle. In some embodiments, the treatment device may include an imaging component, and the imaging component may receive the outgoing beam of the treatment incident beam passing through the radiation object to form a treatment outgoing beam projection image. In some embodiments, the imaging component can acquire a projection image of the treatment exit beam at a certain frequency. For example, the treatment beam image is acquired every 0.5 seconds. In some embodiments, the therapeutic incident beam may be a megavolt (>1 MeV) energy level cone beam. In some embodiments, the radiation source can rotate with the gantry around the isocenter on a fixed plane, so that the therapeutic incident beam can irradiate the target at an angle. For example, if the gantry rotates to the left to 260° and to the right to 100° in the XOY plane with O as the center, the therapeutic incident beam can be set between 260° (left) and -100° (right). The target is irradiated at a fixed angle to generate a treatment beam image corresponding to the set angle.

In some embodiments, the treatment isocenter can be modified before each treatment, so that the isocenter during treatment is consistent with the isocenter of the treatment plan. In some embodiments, image-guided treatment-guided image positioning matching can be performed before each treatment to determine the three-dimensional correction amount between the imaging isocenter and the planned isocenter. The treatment isocenter is corrected according to the three-dimensional correction amount between the imaging isocenter and the planned isocenter. For example, by matching the treatment guide image with the positioning CT image of the treatment plan, the correction amounts of the imaging isocenter and the planned isocenter in the X, Y, and Z directions are +2mm, -1.5mm, and +3mm, respectively. According to the The correction amount adjusts the three-dimensional space position of the worktable 160. The worktable 160 is moved 3mm in the negative direction of the Z axis, 2mm in the negative direction of the X axis, and 1.5mm in the positive direction of the Y axis to make the current isocenter position and the treatment plan The isocenter positions in are consistent. In some embodiments, during actual treatment, the treatment beam needs to irradiate the tumor from different angles. Therefore, the accelerator 111 will rotate with the gantry 113 to obtain different angles of treatment beam projection images. Before radiotherapy, imaging needs to be performed at multiple treatment angles, and a reference reference image corresponding to the treatment angle is established according to the imaging projection image of each angle. During treatment, it is necessary to obtain the treatment beam image at the corresponding treatment angle, calculate the pixel ratio with the reference reference image of the corresponding angle, and monitor the beam dose at this angle. For example, during treatment, the beam will be irradiated at multiple angles between 260 degrees (left) and 100 degrees (right). Before treatment, it is necessary to obtain the imaged beam image at each angle and establish a reference for each angle The reference image, the treatment beam image of each angle is acquired, the treatment beam image of each angle is compared with the reference reference image of the corresponding angle, and the beam dose is monitored.

In some embodiments, the collimator rotation angle can be corrected on the treatment beam image. As mentioned earlier, the collimator angle for imaging is 0°, and the collimator usually rotates to a certain angle during treatment. In order to match the rotation angle of the treatment collimator with the planned collimator angle, the mask image can be rotated when the reference reference image is established, and the rotated mask image and the initial reference reference image are subjected to pixel and calculation to obtain the boundary rotation After the reference reference image, the reference reference image matches the treatment plan.

In some embodiments, the treatment exit beam can be processed to eliminate the influence of uneven rays on the tolerance. In some embodiments, the radiation in the radiation field is usually uneven, the radiation dose rate in the middle position will be relatively high, and the dose rate of the radiation near the edge of the radiation field will be low, with a peak in the middle of the radiation. When the position of the radiotherapy equipment moves, the peak value will also move. The deviation of the imaging isocenter or the treatment isocenter will cause the peak dose to move, resulting in dose error. In some embodiments, the influence of ray non-uniformity can be eliminated by dividing the imaging beam image and the treatment beam image by the empty scan signal under the corresponding coordinates. In some embodiments, the beam reception signal when the target is not irradiated and there is only air can be acquired first to obtain the empty sweep signal. The air scan signal is the attenuation signal of the beam in the air. In some embodiments, the imaged beam image formed by the flattened ray obtained by dividing the imaged beam image by the empty scan signal may be used as the imaged beam image for establishing a reference, and the reference reference image can be established. In some embodiments, the treatment outgoing beam image formed by the flattened rays obtained by dividing the treatment outgoing beam and the empty scan signal can be used as the final treatment outgoing beam image, and the pixel ratio is calculated with the reference image to reduce the radiation. The impact of non-uniformity comparison value and tolerance.

In step 930, it may be determined based on the real-time treatment beam image and the reference reference image whether the pixel value difference between the two meets a preset condition. In some embodiments, step 930 may be performed by the judgment module 320. In some embodiments, the imaging beam and the treatment beam are rays of the same energy level, but the dose rate of the imaging beam and the dose rate of the treatment beam are different. Therefore, in an ideal situation, the pixel ratio of the imaging beam image and the treatment beam image in the same area should be a multiple relationship, and the ratio should be a constant. And in theory, the ratio should be the ratio of the imaging dose rate to the dose rate of the treatment plan. But in fact, due to equipment problems and system errors and other factors, the ratio is difficult to be a constant, but fluctuates within a certain range. In some embodiments, reasonable preset conditions can be set. As long as the ratio of the pixel values of the real-time treatment beam image and the reference image is within the reasonable preset conditions, the treatment beam meets the requirements of the treatment plan. In some embodiments, the pixel value ratio of the corresponding pixel points of the real-time treatment beam image and the reference reference image may be determined based on the pixel value ratio, and whether the pixel value difference is within the tolerance range is determined based on the pixel value ratio . In some embodiments, the tolerance may be determined based on one or a combination of signal-to-noise ratio, output factor, penumbra position, non-uniform ray influence, or equipment stability factor. The determination of tolerance can be found elsewhere in the text, such as the relevant description in Figure 8.

In step 940, the progress of radiotherapy can be controlled based on the judgment result. In some embodiments, step 940 may be executed by the execution module 330. In some embodiments, when the pixel value difference between the real-time treatment beam image and the reference reference image exceeds the tolerance range, the current treatment is stopped. In some embodiments, equipment aging, equipment failure, radiotherapy system errors, changes in the patient’s weight, tissue changes, changes in the patient’s breathing or other human activities during treatment, or changes in the patient’s long-term treatment One or a combination of several conditions, such as body deviation, will cause the treatment beam dose error to become larger, which exceeds the tolerance range. If the ratio of the pixel value between the real-time treatment beam image and the reference reference image exceeds the tolerance range, the treatment beam does not meet the requirements of the plan, and the dose distribution of the treatment beam may seriously deviate from the planned position, which will cause damage to the tissue or the non-tumor area. Damage to the organ. Or the dose rate of the radiation does not meet the plan requirements, which affects the treatment effect. In some embodiments, after stopping the current treatment, the staff can find out the cause of the increased error. If it is caused by equipment failure, increased positioning error, or increased system error, the staff needs to correct the problem. Resume treatment. If it is caused by changes in the patient’s weight or changes in tissues and organs, if necessary, rescan and locate the CT, redesign the treatment plan and update the reference image, and then resume treatment.

Figures 10A-10C are the comparison results of the verification experiment of the aforementioned beam monitoring method. The experiment simulates three types of typical clinical problems, including weight change of the phantom, internal tissue change, and rotation positioning error, and preliminary analysis of the feasibility and sensitivity of the application of the therapeutic beam proposed in this application in dose monitoring during radiotherapy.

Figure 10A shows the monitoring results of radiation therapy beams when the weight of the simulated phantom changes. The images in the leftmost column are the reference images with the angles of the ray source on the gantry at 45°, 0°, 315° and 270°. Wherein, the reference reference image can be generated from the imaging outgoing beam image obtained by irradiating the imaging incident beam to the reference phantom. The images in the middle column are the ratio distribution diagrams of the treatment beam images at the gantry angles of 45°, 0°, 315°, and 270° as the weight change phantom and the corresponding reference reference image. In the experiment, you can cover or remove the cover on the reference phantom to obtain the phantom after weight change. The chart on the far right is a histogram statistics chart of the reference ratio and the simulated ratio. Among them, the dotted line represents the histogram statistics of the ratio distribution map of the treatment beam image of the reference phantom and the reference reference image, and the solid line represents the histogram statistics of the ratio distribution map of the treatment beam image of the phantom after weight change and the reference reference image result. It can be seen that changes in body weight will cause large fluctuations in the pixel ratio between the treatment beam image and the reference image. It can be seen that the radiation therapy monitoring method in this application can monitor the influence of the change in the weight of the radiation target on the radiation dose of the treatment.

Figure 10B shows the monitoring results of radiation therapy beams when the internal tissue of the simulated phantom changes. The images in the leftmost column are the reference images with the angles of the ray source on the gantry at 45°, 0°, 315° and 270°. Wherein, the reference reference image can be generated from the imaging outgoing beam image obtained by irradiating the imaging incident beam to the reference phantom. The middle column of images is the ratio distribution map of the phantom with internal tissue changes at 45°, 0°, 315°, and 270° gantry angles, and the ratio of the treatment beam image to the corresponding reference image. In the experiment, the medium in the reference phantom can be changed from air to a contrast agent to simulate changes in the contents of the intestine. The chart on the far right is a histogram statistics chart of the reference ratio and the simulated ratio. Among them, the dashed line represents the histogram statistics of the ratio distribution map of the treatment beam image of the reference phantom and the reference reference image, and the solid line represents the histogram statistics of the ratio distribution map of the treatment beam image of the phantom after tissue change and the reference reference image result. It can be seen that tissue changes will cause large fluctuations in the ratio of pixels between the treatment beam image and the reference image. It can be seen that the radiation therapy monitoring method in the present application can monitor the effect of changes in the radiation target tissue on the treatment beam dose.

Figure 10C shows the monitoring results of radiation therapy beams when the simulation phantom has different degrees of error. The images in the leftmost column are the reference images with the angles of the ray source on the gantry at 45°, 0°, 315° and 270°. Wherein, the reference reference image can be generated from the imaging outgoing beam image obtained by irradiating the imaging incident beam to the reference phantom. The images in the middle column are the ratio distribution diagrams of the treatment beam image and the corresponding reference reference image at 45°, 0°, 315°, and 270° gantry angles of the phantom with changing position. In the experiment, the position of the reference phantom can be offset, or the reference phantom can be rotated to simulate the position change. The chart on the far right is a histogram statistics chart of the reference ratio and the simulated ratio. Among them, the dashed line represents the histogram statistical result of the ratio distribution map of the treatment beam image of the reference phantom and the reference reference image, and the solid line represents the histogram of the ratio distribution map of the treatment beam image of the phantom after the position change and the reference reference image statistical results. It can be seen that changes in the positioning will cause large fluctuations in the pixel ratio of the treatment beam image and the reference image. It can be seen that the radiation therapy monitoring method in the present application can monitor the effect of changes in the positioning of the radiation target on the radiation dose of treatment.

It can be seen from the above that if similar influencing factors occur in the human body during the treatment process, or the system error becomes larger, the monitoring method of this application can detect the change of the output beam dose error, and monitor the output beam dose distribution to avoid radiation The treatment process causes damage to non-tumor areas or the dose is not accurate, which affects the normal treatment process.

One of the embodiments of the present application also provides a method for obtaining a reference image for radiotherapy. In some embodiments, the method includes: acquiring an outgoing beam obtained by an imaging incident beam passing through a radiation object, and generating an imaging outgoing beam image based on the outgoing beam; performing position coordinate correction on the imaging outgoing beam image to obtain an initial reference reference image Position matching of the initial reference reference image based on the treatment field to obtain an area corresponding to the treatment field in the initial reference reference image, and determine the area as the reference reference image; wherein the imaging incident beam is The therapeutic incident beam of the radiotherapy is a beam of the same energy level. In some embodiments, the imaging incident beam and the treatment incident beam are from the same radiation source. For example, the imaging incident beam and the therapeutic incident beam are generated by the same accelerator. In some embodiments, the imaging incident beam and the therapeutic incident beam may be beams with the same energy spectrum. For example, the imaging incident beam and the treatment incident beam can come from different ray sources. The imaging and treatment incident beams can be beam-matched first, so that the imaging incident beam and the treatment incident beam are adjusted to have the same energy spectrum. Beam.

One of the embodiments of the present application also provides a system for acquiring a reference image for radiotherapy. In some embodiments, the system includes: an acquisition module for acquiring an outgoing beam obtained by an imaging incident beam passing through a radiation object, and generating an imaging outgoing beam image based on the outgoing beam; a reference reference image determining module for outgoing the imaging The beam image undergoes position coordinate correction to obtain an initial reference reference image; the initial reference reference image is position-matched based on the treatment field to obtain an area corresponding to the treatment field in the initial reference reference image, and the area is determined as the reference reference Image; wherein the imaging incident beam and the therapeutic incident beam of the radiotherapy are beams of the same energy level.

The possible beneficial effects of the embodiments of the present application include but are not limited to: (1) The therapeutic beam and the imaging beam are beams of the same energy level, and a reference reference image can be established by imaging the beam image, which facilitates the treatment beam dose (2) It provides a method for establishing a reference image based on the imaging beam image and treatment plan and a method for determining tolerances, which improves the accuracy of monitoring; (3) Because the treatment beam and the imaging beam are the same The energy level beam can record the imaging dose and count the imaging dose into the therapeutic dose, avoiding additional risk burden for the patient. It should be noted that different embodiments may produce different beneficial effects. In different embodiments, the possible beneficial effects may be any one or a combination of the above, or any other beneficial effects that may be obtained.

The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only an example, and does not constitute a limitation to the application. Although it is not explicitly stated here, those skilled in the art may make various modifications, improvements and amendments to this application. Such modifications, improvements, and corrections are suggested in this application, so such modifications, improvements, and corrections still belong to the spirit and scope of the exemplary embodiments of this application.

At the same time, this application uses specific words to describe the embodiments of the application. For example, "one embodiment", "an embodiment", and/or "some embodiments" mean a certain feature, structure, or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that “one embodiment” or “one embodiment” or “an alternative embodiment” mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. . In addition, some features, structures, or characteristics in one or more embodiments of the present application can be appropriately combined.

In addition, those skilled in the art can understand that various aspects of this application can be illustrated and described through a number of patentable categories or situations, including any new and useful process, machine, product, or combination of substances, or for them Any new and useful improvements. Correspondingly, various aspects of the present application can be completely executed by hardware, can be completely executed by software (including firmware, resident software, microcode, etc.), or can be executed by a combination of hardware and software. The above hardware or software can all be called "data block", "module", "engine", "unit", "component" or "system". In addition, various aspects of this application may be embodied as a computer product located in one or more computer-readable media, and the product includes computer-readable program codes.

The computer storage medium may contain a propagated data signal containing a computer program code, for example on a baseband or as part of a carrier wave. The propagation signal may have multiple manifestations, including electromagnetic forms, optical forms, etc., or a suitable combination. The computer storage medium may be any computer readable medium other than the computer readable storage medium, and the medium may be connected to an instruction execution system, device, or device to realize communication, propagation, or transmission of the program for use. The program code located on the computer storage medium can be transmitted through any suitable medium, including radio, cable, fiber optic cable, RF, or similar medium, or any combination of the above medium.

The computer program codes required for the operation of each part of this application can be written in any one or more programming languages, including object-oriented programming languages such as Java, Scala, Smalltalk, Eiffel, JADE, Emerald, C++, C#, VB.NET, Python Etc., conventional programming languages such as C language, Visual Basic, Fortran 2003, Perl, COBOL 2002, PHP, ABAP, dynamic programming languages such as Python, Ruby and Groovy, or other programming languages. The program code can run entirely on the user's computer, or run as an independent software package on the user's computer, or partly run on the user's computer and partly run on a remote computer, or run entirely on the remote computer or server. In the latter case, the remote computer can be connected to the user's computer through any form of network, such as a local area network (LAN) or a wide area network (WAN), or to an external computer (for example, via the Internet), or in a cloud computing environment, or as a service Use software as a service (SaaS).

In addition, unless explicitly stated in the claims, the order of processing elements and sequences, the use of numbers and letters, or the use of other names in this application are not used to limit the order of the procedures and methods of this application. Although the foregoing disclosure uses various examples to discuss some invention embodiments that are currently considered useful, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments. On the contrary, the rights The requirements are intended to cover all modifications and equivalent combinations that conform to the essence and scope of the embodiments of the present application. For example, although the system components described above can be implemented by hardware devices, they can also be implemented only by software solutions, such as installing the described system on existing servers or mobile devices.

For the same reason, it should be noted that, in order to simplify the expressions disclosed in this application and to help the understanding of one or more embodiments of the invention, in the foregoing description of the embodiments of this application, multiple features are sometimes combined into one embodiment. In the drawings or its description. However, this disclosure method does not mean that the subject of the application requires more features than those mentioned in the claims. In fact, the features of the embodiment are less than all the features of the single embodiment disclosed above.

Some examples use numbers describing the number of ingredients and attributes. It should be understood that such numbers used in the description of the examples use the modifier "about", "approximately" or "substantially" in some examples. Retouch. Unless otherwise stated, "approximately", "approximately" or "substantially" indicate that the number is allowed to vary by ±20%. Correspondingly, in some embodiments, the numerical parameters used in the description and claims are approximate values, and the approximate values can be changed according to the required characteristics of individual embodiments. In some embodiments, the numerical parameter should consider the prescribed effective digits and adopt the general digit retention method. Although the numerical ranges and parameters used to confirm the breadth of the ranges in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values is as accurate as possible within the feasible range.

For each patent, patent application, patent application publication and other materials cited in this application, such as articles, books, specifications, publications, documents, etc., the entire contents of which are hereby incorporated into this application by reference. The application history documents that are inconsistent or conflicting with the content of this application are excluded, and documents that restrict the broadest scope of the claims of this application (currently or later attached to this application) are also excluded. It should be noted that if there is any inconsistency or conflict between the description, definition, and/or use of terms in the attached materials of this application and the content of this application, the description, definition and/or use of terms in this application shall prevail .

Finally, it should be understood that the embodiments described in this application are only used to illustrate the principles of the embodiments of this application. Other variations may also fall within the scope of this application. Therefore, as an example and not a limitation, the alternative configuration of the embodiment of the present application can be regarded as consistent with the teaching of the present application. Accordingly, the embodiments of the present application are not limited to the embodiments explicitly introduced and described in the present application.

Claims

A monitoring method for radiation therapy beams, which is characterized in that it comprises:

Obtaining a reference reference image; the reference reference image is determined based on an imaging exit beam image, and the imaging exit beam image is generated based on an exit beam obtained by an imaging incident beam passing through a radiation object;

Acquiring a real-time treatment beam image; the real-time treatment beam image is generated based on the beam obtained by the treatment incident beam passing through the radiation object in the current radiotherapy process;

Based on the real-time treatment beam image and the reference reference image determine whether the difference in pixel value between the two meets a preset condition;

Control the progress of radiotherapy based on the judgment result;

Wherein, the imaging incident beam and the therapeutic incident beam of radiotherapy are beams of the same energy level.
The method of claim 1, wherein the imaging incident beam and the therapeutic incident beam are from the same radiation source.
The method of claim 1, wherein the imaging beam image is acquired before radiotherapy.
The method according to claim 3, wherein the imaged outgoing beam image is an image used for image guidance of user positioning before radiotherapy.
The method according to claim 1, wherein determining the reference reference image based on the imaging beam image comprises:

Performing position coordinate correction on the imaging beam image to obtain an initial reference reference image;

Perform position matching on the initial reference reference image based on the treatment field, obtain an area corresponding to the treatment field in the initial reference reference image, and determine the area as the reference reference image.
The method according to claim 5, wherein the performing position coordinate correction on the imaged outgoing beam image to obtain an initial reference reference image comprises:

Obtain the imaging isocenter position and the isocenter position of the treatment plan;

The position coordinate correction of the imaging beam image is performed based on the difference between the imaging isocenter position and the treatment plan isocenter position.
The method according to claim 5, wherein said performing position coordinate correction on the imaged beam image to obtain an initial reference reference image further comprises:

Obtain the angle of the collimator during imaging and the angle of the collimator of the treatment plan;

Determining the angle difference between the collimator angle during imaging and the collimator angle of the treatment plan;

Perform position coordinate correction on the imaged outgoing beam image based on the angle difference.
The method of claim 5, wherein the performing position matching on the initial reference reference image based on the treatment field to obtain an area corresponding to the treatment field in the initial reference reference image comprises:

Determine the treatment field based on the position data of the grating in the treatment plan to generate a mask image;

The mask image and the initial reference image are calculated to obtain the corresponding area.
9. The method of claim 8, wherein generating a mask image based on the treatment field further comprises:

Obtain at least one image of the treatment beam;

Determining the boundary information of the actual treatment field based on the treatment beam image;

The mask image is verified based on the boundary information.
The method according to claim 1, wherein determining the reference reference image based on the imaging beam image comprises:

Determine the digital reconstructed image of the planned CT image; the planned CT image is the CT scan image used to determine the treatment plan before treatment;

Obtaining an initial reference reference image based on the digitally reconstructed image of the planned CT image and the imaging beam image;

Perform position matching on the initial reference reference image based on the treatment field, obtain an area corresponding to the treatment field in the initial reference reference image, and determine the area as the reference reference image.
The method according to claim 10, wherein said determining the digital reconstructed image of the planned CT image comprises:

Calculating a plurality of projection data according to S 0 *exp (-μL); and determining a digital reconstruction image of the planned CT image based on the plurality of projection data;

Among them, S 0 is the empty sweep signal minus the background value, the empty sweep signal is the signal collected by the detector when the rays are only attenuated in the air, and the background value is the environmental signal collected by the detector when the radioactive source is not working;

μ is the average attenuation coefficient of rays passing through the human body from one direction;

L is the length of the human body part in the linear distance between the detector and the planned CT radiation source.
The method of claim 10, wherein the obtaining an initial reference reference image based on the digitally reconstructed image of the planned CT and the imaging beam image comprises:

The digital reconstruction image of the planned CT and the imaging beam image are deformed and registered based on an image registration algorithm to obtain the initial reference reference image.
The method according to claim 1, wherein the determining whether the pixel value difference between the real-time treatment beam image and the reference reference image meets a preset condition based on the real-time treatment beam image and the reference reference image comprises:

Determining the ratio of the pixel values of the corresponding pixel points of the two based on the real-time treatment beam image and the reference reference image;

Determine whether the pixel value difference is within a tolerance range based on the pixel value ratio.
The method according to claim 13, wherein the tolerance range is determined based on one or a combination of the following:

S/N ratio, output factor, penumbra position, non-uniform ray influence or equipment stability factor.
The method of claim 13, further comprising:

Perform simulation experiments based on the treatment plan to obtain the simulated ratio between the treatment beam image and the reference image;

The allowable value range is determined based on the analog ratio.
The method of claim 13, wherein the controlling the progress of radiotherapy based on the judgment result comprises:

When the pixel value difference exceeds the tolerance range, the current treatment is stopped.
A radiation therapy beam monitoring system, which is characterized by comprising:

An acquiring module, configured to acquire a reference reference image; the reference reference image is determined based on an imaging exit beam image, and the imaging exit beam image is generated based on an exit beam obtained by an imaging incident beam passing through a radiation object;

The acquisition module is also used to acquire a real-time treatment beam image; the real-time treatment beam image is generated based on the beam obtained by the treatment incident beam passing through the radiation object in the current radiotherapy process;

A judging module for judging whether the pixel value difference between the real-time treatment beam image and the reference reference image meets a preset condition;

The execution module is used to control the radiotherapy process based on the judgment result;

Wherein, the imaging incident beam and the therapeutic incident beam of radiotherapy are beams of the same energy level.
The system of claim 17, wherein the imaging incident beam and the therapeutic incident beam are from the same radiation source.
17. The system of claim 17, wherein the imaged outgoing beam image is acquired before radiotherapy.
The system according to claim 19, wherein the imaged outgoing beam image is an image used for image guidance of the user's positioning before radiotherapy.
17. The system of claim 17, further comprising a reference reference image determining module, the reference reference image determining module being used for:

Performing position coordinate correction on the imaging beam image to obtain an initial reference reference image;

Perform position matching on the initial reference reference image based on the treatment field, obtain an area corresponding to the treatment field in the initial reference reference image, and determine the area as the reference reference image.
The system of claim 21, wherein the reference reference image determining module is further configured to:

Obtain the imaging isocenter position and the isocenter position of the treatment plan;

The position coordinate correction of the imaging beam image is performed based on the difference between the imaging isocenter position and the treatment plan isocenter position.
The system of claim 21, wherein the reference reference image determining module is further configured to:

Obtain the angle of the collimator during imaging and the angle of the collimator of the treatment plan;

Determining the angle difference between the collimator angle during imaging and the collimator angle of the treatment plan;

Perform position coordinate correction on the imaged outgoing beam image based on the angle difference.
The system of claim 21, wherein the reference reference image determining module is further configured to:

Determine the treatment field based on the position data of the grating in the treatment plan to generate a mask image;

The mask image and the initial reference image are calculated to obtain the corresponding area.
The system according to claim 24, wherein the reference reference image determining module is further configured to:

Obtain at least one image of the treatment beam;

Determining the boundary information of the actual treatment field based on the treatment beam image;

The mask image is verified based on the boundary information.
17. The system of claim 17, further comprising a reference reference image determining module, the reference reference image determining module being used for:

Determine the digital reconstructed image of the planned CT image; the planned CT image is the CT scan image used to determine the treatment plan before treatment;

Obtaining an initial reference reference image based on the digitally reconstructed image of the planned CT image and the imaging beam image;

Perform position matching on the initial reference reference image based on the treatment field, obtain an area corresponding to the treatment field in the initial reference reference image, and determine the area as the reference reference image.
The system according to claim 26, wherein the reference reference image determining module is further configured to:

Calculating a plurality of projection data according to S 0 *exp (-μL); and determining a digital reconstruction image of the planned CT image based on the plurality of projection data;

Among them, S 0 is the empty sweep signal minus the background value, the empty sweep signal is the signal collected by the detector when the rays are only attenuated in the air, and the background value is the environmental signal collected by the detector when the radioactive source is not working;

μ is the average attenuation coefficient of rays passing through the human body from one direction;

L is the length of the human body part in the linear distance between the detector and the planned CT radiation source.
The system according to claim 26, wherein the reference reference image determining module is further configured to:

The digital reconstruction image of the planned CT and the imaging beam image are deformed and registered based on an image registration algorithm to obtain the initial reference reference image.
The system according to claim 17, wherein the judgment module is further used for:

Determining the ratio of the pixel values of the corresponding pixel points of the two based on the real-time treatment beam image and the reference reference image;

Determine whether the pixel value difference is within a tolerance range based on the pixel value ratio.
The system according to claim 29, wherein the tolerance range is determined based on one or a combination of the following:

S/N ratio, output factor, penumbra position, non-uniform ray influence or equipment stability factor.
The system according to claim 29, wherein the execution module is further used for:

When the pixel value difference exceeds the tolerance range, the current treatment is stopped.
A radiation therapy beam monitoring device, characterized in that the device includes at least one processor and at least one memory;

The at least one memory is used to store computer instructions;

The at least one processor is configured to execute at least part of the computer instructions to implement the processor as claimed in the claims to execute the radiation therapy exit beam monitoring method according to any one of claims 1-16.
A computer-readable storage medium that stores computer instructions. After the computer reads the computer instructions in the storage medium, the computer executes the radiation therapy beam monitoring method according to any one of claims 1-16.
A method for obtaining a reference reference image for radiotherapy, which is characterized in that it comprises:

Acquiring an outgoing beam obtained by the imaging incident beam passing through the radiation object, and generating an imaging outgoing beam image based on the outgoing beam;

Performing position coordinate correction on the imaging beam image to obtain an initial reference reference image;

Performing position matching on the initial reference reference image based on the treatment field, obtaining an area corresponding to the treatment field in the initial reference reference image, and determining the area as the reference reference image;

Wherein, the imaging incident beam and the therapeutic incident beam of the radiotherapy are beams of the same energy level.
A system for acquiring a reference image for radiotherapy, which is characterized in that it comprises:

An acquisition module for acquiring the emergent beam obtained by the imaging incident beam passing through the radiation object, and generating an imaging emergent beam image based on the emergent beam;

The reference reference image determination module is used to perform position coordinate correction on the imaging beam image to obtain an initial reference reference image; perform position matching on the initial reference reference image based on the treatment field to obtain the initial reference reference image and the treatment field Corresponding area, determining the area as the reference reference image;

Wherein, the imaging incident beam and the therapeutic incident beam of the radiotherapy are beams of the same energy level.
A device for acquiring a reference image for radiotherapy, wherein the device at least includes a processor and at least one memory;

The at least one memory is used to store computer instructions;

The at least one processor is configured to execute at least part of the computer instructions to implement the method for acquiring a reference reference image for radiotherapy according to claim 34.
A computer-readable storage medium that stores computer instructions. After the computer reads the computer instructions in the storage medium, the computer executes the method for obtaining a reference reference image for radiotherapy according to claim 34.
A method for obtaining a reference reference image for radiotherapy, which is characterized in that it comprises:

Determine the digital reconstructed image of the planned CT image; the planned CT image is the CT scan image used to determine the treatment plan before treatment;

Obtaining an initial reference reference image based on the digitally reconstructed image and the imaging beam image of the planned CT image;

Perform position matching on the initial reference reference image based on the treatment field, obtain an area corresponding to the treatment field in the initial reference reference image, and determine the area as the reference reference image.
A device for acquiring a reference image for radiotherapy, which is characterized in that it comprises:

The image reconstruction module determines the digital reconstruction image of the planned CT image; the planned CT image is the CT scan image used to determine the treatment plan before treatment;

A registration module to obtain an initial reference reference image based on the digitally reconstructed image and the imaging beam image of the planned CT image;

The reference reference image determination module performs position matching on the initial reference reference image based on the treatment field, obtains an area corresponding to the treatment field in the initial reference reference image, and determines the area as the reference reference image.
A device for acquiring a reference image for radiotherapy, wherein the device at least includes a processor and at least one memory;

The at least one memory is used to store computer instructions;

The at least one processor is configured to execute at least part of the computer instructions to implement the method for acquiring a reference reference image for radiotherapy according to claim 38.
A computer-readable storage medium that stores computer instructions. After the computer reads the computer instructions in the storage medium, the computer executes the method for acquiring a reference reference image for radiotherapy according to claim 38.