CN118416404A - Online radiotherapy dose reconstruction method, system and device - Google Patents

Abstract

The embodiment of the specification discloses an on-line radiotherapy dose reconstruction method, system and device. Wherein the method comprises the following steps: in a single treatment process of a target object, acquiring radiotherapy auxiliary images corresponding to the current radiation field in a plurality of radiation fields in real time; reconstructing a radiotherapy dosage in real time based on the radiotherapy auxiliary image corresponding to the current radiation field; displaying the radiotherapy dosage corresponding to the current radiation field in the treatment process in real time, or displaying the accumulation result of the radiotherapy dosages corresponding to the radiation fields in the treatment process in real time.

Description

Online radiotherapy dose reconstruction method, system and device

Technical Field

The present disclosure relates to the field of image diagnosis, and in particular, to a method, system, and apparatus for dose reconstruction of on-line radiotherapy.

Background

Radiation therapy is one of the important means for treating malignant tumors, and radiation dose distribution needs to be calculated during radiation therapy, and radiation therapy is performed on a patient according to the calculated radiation dose. The accuracy of the calculated radiation dose distribution affects the evaluation of the therapeutic effect of the radiation treatment, whereby the calculation of the radiation dose distribution is particularly important.

Accordingly, the present embodiments provide an on-line radiotherapy dose reconstruction method, system and apparatus to better calculate a radiation dose distribution.

Disclosure of Invention

One aspect of the embodiments of the present specification provides an on-line radiotherapy dose reconstruction method. The method comprises the following steps: in a single treatment process of a target object, acquiring radiotherapy auxiliary images corresponding to the current radiation field in a plurality of radiation fields in real time; reconstructing a radiotherapy dosage in real time based on the radiotherapy auxiliary image corresponding to the current radiation field; displaying the radiotherapy dosage corresponding to the current radiation field in the treatment process in real time, or displaying the accumulation result of the radiotherapy dosages corresponding to the radiation fields in the treatment process in real time.

In some embodiments, the method further comprises: and comparing the real-time reconstructed radiotherapy dosage with the expected dosage, and determining a comparison result.

In some embodiments, the method further comprises: based on the comparison results, the result of the underdose/overdose analysis of the target region of rays or the ray-jeopardizing organ is given in real time.

In some embodiments, the method further comprises: and based on the comparison result, optimizing the treatment plan of the subsequent radiation fields of the current radiation field in the treatment process in real time.

In some embodiments, the method further comprises: and displaying the comparison result in a visual mode.

In some embodiments, reconstructing the radiotherapy dose in real time based on the radiotherapy auxiliary image corresponding to the current portal comprises: and responding to completion of the acquisition of the radiotherapy auxiliary image corresponding to the current field, and automatically reconstructing the radiotherapy dosage in real time based on the radiotherapy auxiliary image corresponding to the current field.

In some embodiments, the method further comprises: transmitting the radiation therapy auxiliary image to a radiation therapy planning system to reconstruct the radiation therapy dose in real time on the radiation therapy planning system; and displaying the reconstruction result of the radiotherapy dosage in real time through a terminal device connected with the radiotherapy planning system.

In some embodiments, the method further comprises: acquiring a two-dimensional passing rate based on the radiotherapy auxiliary image; and determining an evaluation result of the current radiation field or the treatment result based on the two-dimensional passing rate and a radiation treatment dosage result corresponding to the current radiation field or a radiation treatment dosage result accumulated in the treatment process.

Another aspect of embodiments of the present specification provides an on-line radiotherapy dose reconstruction system. The system comprises: the radiotherapy auxiliary image acquisition module is used for acquiring the radiotherapy auxiliary images corresponding to the current radiation field in the multiple radiation fields in real time in the single treatment process of the target object; the radiotherapy dose reconstruction module is used for reconstructing the radiotherapy dose in real time based on the radiotherapy auxiliary image corresponding to the current radiation field; the real-time display module is used for displaying the radiotherapy dosage corresponding to the current radiation field in the treatment process in real time or displaying the accumulation result of the radiotherapy dosages corresponding to the radiation fields in the treatment process in real time.

Another aspect of the embodiments of the present specification provides an image processing apparatus including at least one storage medium for storing computer instructions and at least one processor; the at least one processor is configured to execute the computer instructions to implement the online radiotherapy dose reconstruction method described above.

Another aspect of the embodiments of the present disclosure provides a computer readable storage medium storing computer instructions that, when read by a computer, perform the above-described method of dose reconstruction for online radiotherapy.

In some embodiments of the present disclosure, the radiotherapy auxiliary image corresponding to the current radiation field of the plurality of radiation fields in the single treatment process is acquired in real time to reconstruct the radiotherapy dosage in real time, so that the radiotherapy dosage for treatment can be fed back to the doctor in real time, and the doctor can optimize the subsequent treatment plan in combination with the radiotherapy dosage displayed in real time, thereby better treating the patient.

Drawings

The present specification will be further elucidated by way of example embodiments, which will be described in detail by means of the accompanying drawings. The embodiments are not limiting, in which like numerals represent like structures, wherein:

FIG. 1 is a schematic illustration of an exemplary application scenario of an on-line radiotherapy dose reconstruction system according to some embodiments of the present description;

FIG. 2 is an exemplary flow chart of an on-line radiotherapy dose reconstruction method according to some embodiments of the present description;

FIG. 3 is an exemplary flow chart of reconstructing a radiation therapy dose according to some embodiments of the present description;

FIG. 4 is an exemplary diagram illustrating real-time display of reconstruction results according to some embodiments of the present description;

FIG. 5 is an exemplary flow chart for determining a rating result according to some embodiments of the present description;

fig. 6 is an exemplary block diagram of an on-line radiotherapy dose reconstruction system according to some embodiments of the present description.

Detailed Description

In order to more clearly illustrate the technical solutions of the embodiments of the present specification, the drawings that are required to be used in the description of the embodiments will be briefly described below. It is apparent that the drawings in the following description are only some examples or embodiments of the present specification, and it is possible for those of ordinary skill in the art to apply the present specification to other similar situations according to the drawings without inventive effort. Unless otherwise apparent from the context of the language or otherwise specified, like reference numerals in the figures refer to like structures or operations.

It will be appreciated that "system," "apparatus," "unit" and/or "module" as used herein is one method for distinguishing between different components, elements, parts, portions or assemblies of different levels. However, if other words can achieve the same purpose, the words can be replaced by other expressions.

As used in this specification and the claims, the terms "a," "an," "the," and/or "the" are not specific to a singular, but may include a plurality, unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" merely indicate that the steps and elements are explicitly identified, and they do not constitute an exclusive list, as other steps or elements may be included in a method or apparatus.

A flowchart is used in this specification to describe the operations performed by the system according to embodiments of the present specification. It should be appreciated that the preceding or following operations are not necessarily performed in order precisely. Rather, the steps may be processed in reverse order or simultaneously. Also, other operations may be added to or removed from these processes.

Fig. 1 is a schematic diagram of an exemplary application scenario of an on-line radiotherapy dose reconstruction system according to some embodiments of the present description.

In some embodiments, the on-line radiotherapy dose reconstruction system 100 may be applied for a medical system platform. For example, the online radiotherapy dose reconstruction system 100 may determine in real-time (online) the actual dose received by a radiotherapy subject (e.g., patient) during radiotherapy. For example, the on-line radiotherapy dose reconstruction system 100 may determine in real-time the actual dose received by a radiotherapy subject (e.g., patient) through auxiliary medical images acquired during radiotherapy.

As shown in fig. 1, the on-line radiotherapy dose reconstruction system 100 may include a radiation therapy device 110, a network 120, a processing device 130, a terminal 140, and a storage device 150. The various components in the radiation therapy dose reconstruction system 100 may be interconnected by a network 120. For example, the processing device 130 and the radiation therapy device 110 can be connected or communicate through the network 120.

The radiation therapy device 110 can deliver a radiation beam to a target object (e.g., a patient or phantom). In some embodiments, the radiation therapy device 110 can include a linear accelerator (also referred to as a linac) 111. The linear accelerator 111 may generate and emit a radiation beam (e.g., an X-ray beam) from the treatment head 112. The radiation beam may pass through one or more collimators (e.g., multi-leaf gratings) having a particular shape and pass to the target object. In some embodiments, the radiation beam may include electrons, photons, or any other type of radiation. In some embodiments, the radiation beam exhibits an energy in the megavolt range (i.e., >1 MeV), and thus may be referred to as a megavolt radiation beam. The treatment head 112 may be coupled to the housing 113. The gantry 113 may rotate, for example, clockwise or counterclockwise about a gantry rotation axis 114. The treatment head 112 may rotate with the gantry 113. In some embodiments, the radiation therapy device 110 can include an imaging assembly 115. The imaging assembly 115 may receive a radiation beam that passes through a target object and may acquire projection images of a patient or phantom before, during, and/or after a radiation therapy or correction procedure. Imaging assembly 115 may include an analog detector, a digital detector, or any combination thereof. The imaging assembly 115 may be attached to the gantry 113 in any manner and/or include a telescoping housing. Thus, rotating the gantry 113 can cause the treatment head 112 and the imaging assembly 115 to rotate synchronously. In some embodiments, the imaging assembly 115 may include an electronic portal imaging device (Electronic Portal IMAGING DEVICE, EPID). In some embodiments, the radiation therapy device 110 can also include a couch 116. The couch 116 may support the patient during radiation therapy or imaging and/or support the phantom during calibration of the radiation therapy device 110. The bed board 116 can be adjusted according to different application scenes.

The network 120 may include any suitable network capable of facilitating the exchange of information and/or data of the brachytherapy dose reconstruction system 100. The data and/or information may include one or more radiation therapy auxiliary images that the radiation therapy device 110 transmits to the processing device 130. For example, the processing device 130 may obtain a radiotherapy-assisted image (such as an EPID image) determined by the imaging assembly 115 from the radiation therapy device 110 via the network 120. As another example, processing device 130 may obtain user (e.g., doctor) instructions from terminal 140 via network 120. In some embodiments, network 120 may be any type of wired or wireless network. In some embodiments, network 120 may include one or more network access points. For example, the network 120 may include wired or wireless network access points, such as base station and/or Internet switching points 120-1, 120-2, …, through which one or more components of the brachytherapy dose reconstruction system 100 may be connected to the network 120 to exchange data and/or information.

The terminal 140 may be in communication and/or connected with the radiation therapy device 110, the processing device 130, and/or the storage device 150. For example, the terminal 140 may obtain a dose determination during radiotherapy from the processing device 130. For another example, the terminal 140 may obtain an image (e.g., a radiotherapy-assisted image) acquired by the radiotherapy device 110 and send the image to the processing device 130 for processing. In some embodiments, the terminal 140 may include a mobile device 140-1, a tablet computer 140-2, a laptop computer 140-3, a desktop computer 140-4, or the like, or any combination thereof. In some embodiments, terminal 140 may be part of processing device 130. In some embodiments, the terminal 140 and the processing device 130 may be integrated as a control device, e.g., a console, of the radiation therapy device 110. In some embodiments, the terminal 140 may be omitted.

Storage device 150 may store data, instructions, and/or any other information. In some embodiments, the storage device 150 may store information that a user controls the behavior of the radiation therapy device 110. In some embodiments, the storage device 150 may store data obtained from the radiation therapy device 110, the terminal 140, and/or the processing device 130. In some embodiments, the storage device 150 may store data and/or instructions that the processing device 130 uses to perform or use to complete the exemplary methods described herein. In some embodiments, the storage device 150 may include mass storage, removable storage, volatile read-write memory, read-only memory (ROM), and the like, or any combination thereof. In some embodiments, storage device 150 may be implemented on a cloud platform.

In some embodiments, the storage device 150 may be connected to the network 120 to communicate with at least one other component (e.g., the processing device 130, the terminal 140) in the brachytherapy dose reconstruction system 100. At least one component of the radiation dose reconstruction system 100 may access data or instructions stored in the storage device 150 via the network 120. In some embodiments, the storage device 150 may be part of the processing device 130.

In some embodiments, the online radiotherapy dose reconstruction system 100 may also include one or more power supplies (not shown in fig. 1) connected to one or more components of the online radiotherapy dose reconstruction system 100 (e.g., the processing device 130, the radiotherapy device 110, the terminal 140, the storage device 150, etc.).

It should be noted that the foregoing description is provided for the purpose of illustration only and is not intended to limit the scope of the present application. Many variations and modifications will be apparent to those of ordinary skill in the art, given the benefit of this disclosure. The features, structures, methods, and other features of the described exemplary embodiments of the application may be combined in various ways to obtain additional and/or alternative exemplary embodiments. For example, the storage device 150 may be a data storage device including a cloud computing platform, such as a public cloud, a private cloud, a community, a hybrid cloud, and the like. However, such changes and modifications do not depart from the scope of the present application.

Fig. 2 is an exemplary flow chart of an on-line radiotherapy dose reconstruction method according to some embodiments of the present description. In some embodiments, the process 200 may be performed by a processing device (e.g., the processing device 130). For example, the flow 200 may be stored in a storage device (e.g., a processing device's own memory unit or external storage device) in the form of a program or instructions that, when executed, may implement the flow 200. The process 200 may include the following operations.

Step 202, acquiring radiotherapy auxiliary images corresponding to the current field in a plurality of fields in real time in a single treatment process of a target object. In some embodiments, step 202 may be performed by the radiotherapy-assisted image acquisition module 610.

The target object may include a patient or other medical subject (e.g., a test mouse or other animal), and the like. In some embodiments, the target object may also be part of a patient or other medical subject, including organs and/or tissues, e.g., heart, lung, ribs, abdominal cavity, etc.

The target subject may need to receive one or more treatments depending on the pre-specified treatment plan. The single treatment may be one treatment for which a treatment plan is set. For example, a single treatment may be to receive a dose of radiation therapy for a certain period of time; for another example, a single treatment may also be a treatment that is received by the subject from being positioned in the treatment couch to being removed from the treatment couch. The specification does not limit the definition of a single treatment.

The field may also be referred to as a radiation field, which may refer to the extent of a desired illuminated site on the body surface of the target object. The radiation travels straight after exiting the accelerator and is scattered in a cone shape. Because the radiation therapy range, the radiation direction, the radiation angle and the radiation distance from the tumor are different, the projection of the tumor on the body surface is also different, so that the irradiation of the whole target area for therapy can be finally realized by utilizing a plurality of radiation fields, and other organs are prevented from being endangered while the target area is irradiated more accurately. In some embodiments, the treatment times (radiotherapy moments) corresponding to the plurality of radiation fields may be different, for example, the plurality of radiation fields may be treated in a certain order according to a treatment plan, or the plurality of radiation fields may be treated in a random order.

The current field refers to the field currently delivering radiation exposure. In some embodiments, the current field may be one or more of a plurality of fields.

The radiotherapy assistance image may comprise a medical image derived by an imaging component of the radiotherapy apparatus based on data generated by received radiation passing through the target object when the radiotherapy is being administered. For example, a radiation therapy assist image may refer to a medical image received by an imaging assembly (e.g., imaging assembly 115) and derived based on data generated by the received radiation after the radiation delivered by the radiation source (e.g., linear accelerator 111) at the time of radiation therapy passes through the target object. In some embodiments, the radiotherapy assistance image may include an EPID (Electronic Portal IMAGING DEVICE ) image.

Each field may correspond to a gantry angle. The gantry angle may refer to the rotation angle of the gantry of the radiation treatment apparatus, which is indicated by a control node specified by the radiation treatment plan. The radiation therapy plan may define a plurality of control nodes, each of which may correspond to a field. The radiotherapy plan may include at each control node the status of various components of the radiotherapy apparatus being planned, the radiotherapy apparatus being to deliver radiation to the target object at various gantry angles, or to deliver radiation continuously over an angular range of two gantry angles.

In some embodiments, the acquired radiotherapy auxiliary image may be determined according to a gantry angle, for example, for a common intensity modulated radiotherapy plan type, a radiotherapy auxiliary image may be output after accumulating the pictures under each fixed gantry angle, and for an arc-striking type, a radiotherapy auxiliary image may be output after accumulating the pictures within a fixed gantry angle range (e.g., 2 °).

In some embodiments, the processing device may reconstruct a radiotherapy-assisted image based on the detectors in the EPID, detecting radiation passing through the target object, and converting the detected radiation into electrical or digital signals (which may also be referred to as projection data).

In some embodiments, in response to completion of the acquisition of the radiation auxiliary image corresponding to the current field, the processing device may automatically reconstruct the radiation dose in real time based on the radiation auxiliary image corresponding to the current field. Automatic real-time reconstruction of radiotherapy doses is of great clinical significance, which can help guide doctors in subsequent procedures.

In some embodiments, after the acquisition of the radiotherapy auxiliary image corresponding to the current portal is completed, the processing device may also reconstruct the radiotherapy dosage in real time based on the radiotherapy auxiliary image corresponding to the current portal in response to a user operation (e.g., clicking, gesture, etc.).

And 204, reconstructing the radiotherapy dosage in real time based on the radiotherapy auxiliary image corresponding to the current radiation field. In some embodiments, step 204 may be performed by a radiotherapy dose reconstruction module 620.

Reconstructing the radiation dose in real time may refer to reconstructing the radiation dose during the treatment of the target subject on the treatment couch. During this process, the target subject does not leave the couch or wait too long for the reconstruction of the radiotherapy dose to be completed. Through reconstructing the radiotherapy dosage in real time, a doctor can quickly know the treatment condition under the condition that a target object to be treated does not leave, and further realize adjustment and optimization of a subsequent treatment plan.

In some embodiments, reconstructing the radiation therapy dose in real time may also be referred to as reconstructing the radiation therapy dose online.

In some embodiments, the processing device may implement reconstruction of the radiation dose based on the radiation auxiliary image corresponding to the current field, the radiation source related data, and the flux map corresponding to the current field. In some embodiments, the reconstructed radiotherapy dose may be a two-dimensional dose or a three-dimensional dose obtained by summing two-dimensional doses, which is not limited in this specification. For more description of the reconstructed radiation doses, see the description of fig. 3.

In some embodiments, after obtaining the real-time reconstructed radiotherapy dose, the processing device may compare the real-time reconstructed radiotherapy dose to an expected dose, and determine a comparison result. The expected dose may be a radiation therapy dose that is estimated to be delivered to the target subject during the radiation therapy treatment when the treatment plan is determined. The comparison result may be a result of comparing the size of the real-time reconstructed radiation dose with the size of the radiation dose of the intended dose. For example, the comparison may include that the real-time reconstructed radiation dose is greater than the expected dose, that the real-time reconstructed radiation dose is less than the expected dose, that the real-time reconstructed radiation dose is close to the expected dose (e.g., the same or a dose difference is less than a preset value), and that the real-time reconstructed radiation dose is different from the expected dose, etc.

In some embodiments, after the comparison result is determined, the comparison result may be visually displayed. To facilitate the physician's observation and to guide the physician through the visual interface for subsequent operations, such as viewing the underrun/overdose analysis results, optimizing the treatment plan, etc.

Specific visualization methods can include text, images, and video, which are not limited in this specification.

In some embodiments, the processing device may give in real time, based on the comparison, a result of the underrun/overrun analysis of the target region of radiation or the organ at risk of radiation. The underdose and the overdose are qualitative descriptions of the radiation dose corresponding to the current field, which can be used to indicate whether the dose of the current radiation therapy reaches the intended dose. The underdose or overdose analysis result may be determined based on the comparison result, e.g. the current real-time reconstructed radiotherapy dose being smaller than the expected dose may be considered as an underdose, or the current real-time reconstructed radiotherapy dose being smaller than the expected dose by an amount exceeding a certain threshold may be considered as an underdose; for another example, a current real-time reconstructed radiation dose that is greater than the expected dose may be considered an overdose, or an overdose when the current real-time reconstructed radiation dose is greater than the expected dose by more than a certain threshold.

The underdose/overrun may be determined only for the target region of radiation or for the organ at risk of radiation, or may be determined for both the target region of radiation and the organ at risk of radiation. For example, for a real-time reconstructed radiotherapy dose, there may be a case where the dose is suitable for a target region of rays, but the radiotherapy dose is excessive for a ray endangering organ, at this time, it may be determined whether or not it is determined that the dose is excessive based on the comparison result and the actual situation (e.g., a therapeutic condition of a target object) in combination. In some implementations, the analysis results may also include an analysis result of the target region of the radiation and an analysis result of the organ-at-risk of the radiation, which may be the same or different.

In some embodiments, the processing device may optimize the treatment plan for subsequent shots of the current shot during the treatment in real time based on the comparison. For example, when the comparison results in a real-time reconstructed radiation dose greater than the expected dose, the radiation dose in the subsequent treatment plan may be reduced. By optimizing the treatment plan corresponding to the treatment process in real time, the radiation dose can be timely adjusted, the condition of insufficient or excessive treatment is avoided, and the radiation dose is prevented from being brought to other organs while the target object is better treated.

Step 206, displaying the radiotherapy dosage corresponding to the current radiation field in the treatment process in real time, or displaying the accumulation result of the radiotherapy dosages corresponding to the radiation fields in the treatment process in real time. In some embodiments, step 206 may be performed by real-time display module 630.

Real-time display may refer to simultaneous display during treatment of the target subject, or display after a short delay. For example, for this treatment, the corresponding radiotherapy dose for the current field may be displayed during the treatment, and the corresponding time point may be the first field of this treatment, or the current field after one or more fields have been completed, or there may be a field after the current field that has not been irradiated.

The display of the radiotherapy dose can be that of a single radiation field, for example, the radiotherapy dose corresponding to the current radiation field in the treatment process can be displayed in real time, and the result of accumulating the radiotherapy doses corresponding to the completed radiation fields can also be that of accumulating the radiotherapy doses corresponding to the completed radiation fields.

In some embodiments of the present disclosure, the radiotherapy auxiliary image corresponding to the current radiation field of the plurality of radiation fields in the single treatment process is acquired in real time to reconstruct the radiotherapy dosage in real time, so that the radiotherapy dosage for treatment can be fed back to the doctor in real time, and the doctor can optimize the subsequent treatment plan in combination with the radiotherapy dosage displayed in real time, thereby better treating the patient. Meanwhile, the radiotherapy dosage is displayed in real time, so that a doctor can more actively carry out subsequent operations, such as adjusting the expected dosage corresponding to the subsequent field of the treatment under the condition that the doctor views the radiotherapy dosage of the treatment in time, and real-time optimization of the treatment plan is realized.

Fig. 3 is an exemplary flow chart of reconstructing a radiation therapy dose according to some embodiments of the present description. In some embodiments, the process 300 may be performed by a processing device (e.g., the processing device 130). For example, the flow 300 may be stored in a storage device (e.g., a self-contained memory unit of a processing device or an external memory device) in the form of a program or instructions that, when executed, may implement the flow 300. The process 300 may include the following operations.

Step 302, acquiring radiation source related data and an initial flux map corresponding to the current field.

The radiation source related data may be parameters of the devices and/or components associated with radiation delivery. The apparatus and/or components may include a radiation source, an accelerator, a collimator, etc. Exemplary parameters may include radiation energy, beam spot size, collimator physical parameters such as leaf length, leaf thickness, range of motion, etc. of a multi-leaf collimator. In some embodiments, the radiation source related data may include a source model.

In some embodiments, the initial flux map corresponding to the current field may be a predetermined image. For example, the initial flux map may be any piece of medical image. For another example, the initial flux map may be an image of data received by the imaging assembly after the radiation treatment device emits a beam of radiation through the target object or phantom.

In some embodiments, the processing device may obtain the radiation source related data and the initial flux map corresponding to the current field by reading from a storage device, reading from a database, or the like. The radiation source related data and the initial flux map may be predetermined and stored to a storage device or database.

A target flux map corresponding to the current portal is determined 304 by one or more iterations based at least on the radiotherapy assistance image, the initial flux map, and the radiation source related data.

The target flux map may be an image for reflecting relevant state information of the radiation source corresponding to the current field. In some embodiments, the processing device may determine the final target flux map by simulating in a iterative simulation, such as a physical course of motion of the ray particles. The processing device may iteratively determine and update the flux map in one or more iterations. Each iteration may be a simulation and update of the flux map.

In some embodiments, the radiotherapy-assisted image may be a corrected image. For example, the processing device may correct the radiotherapy assistance image to obtain a corrected radiotherapy assistance image and determine a target flux map corresponding to a target radiotherapy instant by one or more iterations based on the corrected radiotherapy assistance image, the initial flux map, and the radiation source related data. In some embodiments, the correction may include dead spot correction, dark current correction, gain correction, geometric correction, or the like, or any combination thereof.

In some embodiments, at each of one or more iterations, the processing device may acquire scanned image information of the target object and determine a radiation therapy prediction image in a current iteration round based on the radiation source related data, a current flux map corresponding to the current iteration round, and the scanned image information. Exemplary scan image information may include CR image information, DR image information, CT image information, MRI image information, PET image information, and the like, or any combination thereof. In some embodiments, the scanned image information may be pre-acquired prior to the current portal treatment. In some embodiments, the processing device may determine a radiation therapy prediction image in a current iteration round by a Monte Carlo method (Monte Carlo Method) based on the radiation source related data, a current flux map corresponding to the current iteration round, and the scanned image information.

In some embodiments, the processing device may determine whether the radiotherapy assistance image and the radiotherapy prediction image in the current iteration round satisfy the determination condition. The determination condition may include that the radiotherapy predicted image in the current iteration round converges to the radiotherapy auxiliary image. Convergence may mean that the difference between the radiotherapy predicted image and the radiotherapy auxiliary image in the current iteration round is less than a preset threshold. The difference may relate to a difference between pixel values of corresponding pixels in the two images. In response to the radiotherapy assistance image and the radiotherapy prediction image in the current iteration round satisfying the judgment condition, the processing apparatus may determine a current flux map corresponding to the current iteration round as the target flux map. In response to the radiotherapy auxiliary image and the radiotherapy predicted image in the current iteration round not meeting the judgment condition, the processing device can update the current flux map corresponding to the current iteration round, and take the updated current flux map corresponding to the current iteration round as the current flux map corresponding to the next iteration round. The processing device may determine a difference between the radiotherapy assistance image and the radiotherapy prediction image in the current iteration round. The difference may be a difference matrix between a first matrix representing the radiotherapy assistance image and a second matrix representing the radiotherapy prediction image in the current iteration round. The processing device may update the current flux map corresponding to the current iteration round based on the difference to determine a target flux map.

Step 306, obtaining a target scan image of the target object.

The target scan image may be used to represent the state of the target object during the current portal treatment. The target scan image may correspond to a current field of the plurality of fields.

In some embodiments, the processing device may acquire a plurality of scanned images of the target object before a treatment time corresponding to the current portal, and determine a plurality of predicted phase images of the target object corresponding to the plurality of phases, respectively, at the treatment time corresponding to the current portal. The plurality of scanned images may include a plurality of scanned images reflecting different motion states of the target object in one or more autonomous motion periods. The plurality of scanned images may be pre-scanned prior to a treatment time corresponding to the current portal. In some embodiments, the plurality of scan images may include a plurality of images acquired based on a conventional manner or a plurality of 4D-CT images acquired based on a 4D computed tomography imaging apparatus (Four-dimensional-computed tomography, 4D-CT). The conventional manner may be based on images acquired by various known imaging apparatuses, such as a computed tomography imaging apparatus, a magnetic resonance imaging apparatus, and the like, which is not limited in this specification.

In some embodiments, the predicted phase image may refer to a predicted image that may reflect the state of the target object when the current portal corresponds to treatment. To determine a plurality of predicted phase images for the plurality of phases, the processing device may acquire a radiation therapy plan and determine planned beam out information at a time of treatment for the current radiation field based on the radiation therapy plan. The planned beam information may include beam intensity, beam conformal shape, radiation dose, etc. For each of a plurality of phases, the processing device may obtain information about the phase. The phase-related information may include state information or phase information in which the target object is located at the phase. For example, the phase-related information may include a phase in which the target object (such as a patient, or an organ or tissue of a patient) is in physiological motion (e.g., systole, diastole, etc. of heart motion), a posture of the target object (e.g., lying on its side, etc.), morphology, body shape, etc. The processing device may determine a predicted phase image corresponding to the phase based on the planned beam information and the phase related information. For example, the processing device may acquire the predicted phase image using a simulated method.

In some embodiments, the processing device may determine an adapted image of the radiotherapy assistance image from the plurality of predicted phase images. The adapted image may refer to a predicted phase image closest to the radiotherapy assistance image corresponding to the treatment time corresponding to the current portal. For example, the state of the target object displayed by the adapted image is closest to the state of the target object displayed by the radiotherapy-assisted image. In some embodiments, the processing device may determine an adapted image of the radiotherapy assistance image using a feature matching method. For example, the processing device may compare a feature distribution (e.g., a gray distribution feature) of the plurality of predicted phase images with a gray distribution feature of the radiotherapy-assisted image, and select, as the adaptation image, a predicted phase image whose feature distribution is closest to the gray distribution feature of the radiotherapy-assisted image.

In some embodiments, the processing device may determine first location information of the target tissue contained in the radiotherapy assistance image and second location information of the target tissue contained in each of the plurality of predicted phase images. The target tissue may refer to a tissue having a distinguishing property in the target object. For example, a tumor area, or an organ, etc. The processing device may determine an adapted image of the radiotherapy assistance image based on the first location information and the second location information. As an example, the processing device may compare the first position information with the second position information corresponding to each predicted phase image. When the first position information matches with the second position information corresponding to a certain predicted phase image, the processing device may determine the predicted phase image as an adapted image.

In some embodiments, the processing device may determine a target phase corresponding to the adapted image and designate a scan image corresponding to the target phase as the target scan image.

Step 308, determining a radiotherapy dosage received by the target object in the current portal based on the target flux map, the target scan image and the radiation source related data.

In some embodiments, the processing device determines a radiation therapy dose received by the target subject at the current portal by a monte carlo method (Monte Carlo Method). In some embodiments, the Monte Carlo method may be used to simulate various physical processes (e.g., scattering, attenuation, etc.) of the ray particles in the target object. As an example, the processing device may simulate the transport process of the radiation particles by means of the monte carlo method, e.g. under the parameter conditions of the radiation delivery related device and/or component as reflected by the radiation source related data and under the state conditions of the radiation source as reflected by the target flux map, after passing through the inner region of the target object as reflected by the target scan image, resulting in a final dose distribution. Based on the dose distribution, a processing device may determine a radiation dose received by the target object at a current field.

In some embodiments, based on the same or similar procedure described above, the processing device may obtain radiation doses received by a plurality of shots of the target object during a radiation treatment, and determine a cumulative result of radiation doses corresponding to the plurality of shots of the target object during the radiation treatment up to the current shot based on the radiation doses received by the plurality of shots. The radiation therapy device will deliver radiation to the target object at each gantry angle, or continuously deliver radiation over an angular range of two gantry angles. The processing device may determine radiation doses received by the target subject at each gantry angle and accumulate the radiation doses to determine an accumulated result of radiation doses for the target subject at a plurality of radiation fields.

FIG. 4 is an exemplary diagram illustrating real-time display of reconstruction results according to some embodiments of the present description.

In some embodiments, the processing device may send radiotherapy assistance images to the radiotherapy planning system to reconstruct the radiotherapy doses in real time on the radiotherapy planning system; and displaying the reconstruction result of the radiotherapy dosage in real time through one or more terminal devices connected with the radiotherapy planning system.

In one application scenario, the radiation therapy system can be connected to a computing device 1, which computing device 1 can be used to acquire radiotherapy-assisted images. A computing device may refer to a device having computing/data processing capabilities, such as a computer, server, or the like. The radiotherapy planning system can be arranged on a computing device 2 in another room, the radiotherapy planning can be arranged on the computing device 2, and the arranged radiotherapy planning (also called as a treatment planning) can be arranged on a corresponding computing device or a terminal device according to the requirement. For example, the formulated, adjusted radiation therapy plan may be sent to a computing device (e.g., computing device 1) or terminal device to which the radiation therapy system is connected. For example, a user may initiate a request to view a radiation therapy plan through a computing device or a terminal device, and computing device 2 sends the radiation therapy plan to the corresponding device according to the received request. The terminal device may include a smart phone, tablet, notebook, desktop, etc.

In one application scenario, the radiation therapy planning system may be migrated (or setup) to a computing device 1 connected to the radiation therapy system. In this way, the radiotherapy assistance image may be acquired directly from the computing device 1 without separately sending the radiotherapy assistance image to the radiotherapy plan, simplifying the workflow.

In some embodiments, the radiotherapy planning system, the computing device to which the radiotherapy system corresponds, and the terminal device may be interconnected by a network. Illustratively, as shown in fig. 4, the radiation therapy planning system 410 may be connected (may be a wired connection or a wireless connection) to the computing device 420, the radiation therapy system 430 may be connected (may also be a wired connection or a wireless connection) to the computing device 440, and the computing device 420 and the computing device 440 may be connected to a network (e.g., network 120). Terminal device 450, terminal device 460, and terminal device 470 may also be connected to a network to enable information transfer to and from computing device 420 and computing device 440 via the network. In some embodiments, the terminal device may be located in a different room than the computing device; the respective terminal device and the respective computing device may also be located in different rooms. For example, the computing device corresponding to the radiation therapy system may be located in room a, the computing device corresponding to the radiation therapy planning system may be located in room B, and the terminal device may be located in room C. The location of the computing device and the terminal device, and the connection between them, may be flexibly set, which is not limited in this specification. In this embodiment, even if the doctor is not in front of the computing device corresponding to the radiotherapy system, the doctor can quickly learn about the dose condition of the radiotherapy through other devices, for example, the computing device or the terminal device corresponding to the radiotherapy planning system, so as to optimize the radiotherapy plan in real time based on the current radiotherapy dose of the radiotherapy.

Fig. 5 is an exemplary flow chart for determining a rating result according to some embodiments of the present description. In some embodiments, the process 500 may be performed by a processing device. For example, the flow 500 may be stored in a storage device (e.g., a self-contained memory unit of a processing device or an external memory device) in the form of a program or instructions that, when executed, may implement the flow 500. The process 500 may include the following operations.

Step 502, acquiring a two-dimensional passing rate based on the radiotherapy auxiliary image.

The two-dimensional passing rate is an index for evaluating the irradiation condition of the current field. For example, after a treatment plan is determined, an expected examination may be included in the treatment plan, which would have a corresponding expected dose. Each portal irradiation may have a corresponding expected dose. During actual treatment, after the irradiation of the current radiation field, the corresponding auxiliary image of the radiotherapy is acquired to reconstruct in real time, so that the actual radiotherapy dosage is obtained, and the difference of the radiotherapy dosages can be determined by comparing the actual radiotherapy dosage with the expected radiotherapy dosage. The two-dimensional pass rate is an index for evaluating the degree of similarity of an actual radiotherapy dose to an intended radiotherapy dose based on the radiotherapy dose difference.

In some embodiments, the processing device may acquire the 2D dose image based on the radiotherapy-assisted image. For example, a portal dose reconstruction model may be used to convert the radiotherapy assistance image obtained at the corresponding current portal into a corresponding 2D dose image. The dose image may reflect an absolute dose distribution at the plane of the EPID and be obtained by converting the gray scale pixel values into dose values or simulation of gray scale pixel values. To convert the radiotherapy assistance image into a 2D dose image, either an empirical or simulation model may be used. For example, the EPID signal may be converted to a dose using a calibrated detector such as, but not limited to, an ionization chamber or miniature artifacts inside the water or film; the detector response may also be simulated or modeled by Monte Carlo (Monte Carlo) or other empirical simulation techniques.

After the 2D dose image is obtained, the radiotherapy dose can be compared with the expected radiotherapy dose 2D dose, the dose difference between the two is determined, and the two-dimensional passing rate is determined based on the size of the difference. For example, the processing device may directly use the magnitude of the difference as the two-dimensional passing rate, or may perform a certain conversion based on the difference to determine the two-dimensional passing rate.

In some embodiments, the two-dimensional pass rate may be represented by a numerical value, e.g., 70, 89, 90, etc. The magnitude of the value may be used to reflect how similar the actual radiation dose is to the intended radiation dose, e.g., the larger the value, the higher the degree of similarity. Meanwhile, a two-dimensional passing rate threshold value can be set, for example, the threshold value can be 85, and when the two-dimensional passing rate exceeds the threshold value, the treatment corresponding to the current radiation field in the treatment process can be considered to be better or expected.

Step 504, determining an evaluation result of the current radiation field or the therapeutic result based on the two-dimensional passing rate and the therapeutic dose result corresponding to the current radiation field or the therapeutic result accumulated in the therapeutic process.

The evaluation result may be used to reflect the current portal or the therapeutic effect of the treatment. The higher the evaluation result, the better the therapeutic effect reflecting the current spot or the treatment (the closer to the expected therapeutic effect, the better the therapeutic effect can be considered).

In some embodiments, the processing device may determine an evaluation result of the current portal based on the two-dimensional pass rate and a radiotherapy dose result corresponding to the current portal. Or the processing device may determine an evaluation of the outcome of the treatment based on the two-dimensional throughput rate and the radiation therapy dose outcome accumulated during the treatment.

In some embodiments, the processing device may add an evaluation result to the corresponding radiotherapy dose result based on the magnitude of the two-dimensional pass rate, the higher the two-dimensional pass rate, the better the corresponding evaluation result.

In this embodiment, by evaluating the current field or the treatment result of the current field by combining the two-dimensional passing rate, a doctor can intuitively understand the treatment effect of the current field or the treatment of the current field, so that the doctor can evaluate whether the treatment of other subsequent fields is suitable and perform corresponding treatment plan adjustment based on the evaluation result of the current field, and can also judge whether the treatment plan of the subsequent round of treatment is suitable and perform corresponding treatment plan adjustment based on the evaluation result of the treatment result, so as to better treat the patient.

It should be noted that the above descriptions are only for illustration and description, and do not limit the application scope of the present specification. Various modifications and changes to the various processes will be apparent to those skilled in the art in light of the present description. However, such modifications and variations are still within the scope of the present description. For example, changes to the flow steps associated with the present description, such as adding pre-processing steps and storing steps, etc.

Fig. 6 is an exemplary block diagram of an on-line radiotherapy dose reconstruction system according to some embodiments of the present description. As shown in fig. 6, the system 600 may include a radiotherapy-assisted image acquisition module 610, a dose reconstruction module 620, and a real-time display module 630.

The radiotherapy auxiliary image acquisition module 610 may be configured to acquire, in real time, a radiotherapy auxiliary image corresponding to a current field of the plurality of fields during a single treatment of the target object.

The dose reconstruction module 620 may be configured to reconstruct a radiotherapy dose in real time based on the radiotherapy auxiliary image corresponding to the current radiation field.

The real-time display module 630 may be configured to display the radiotherapy dose corresponding to the current radiation field in the treatment process in real time, or display the accumulation result of the radiotherapy doses corresponding to the multiple radiation fields in the treatment process in real time.

For more description of the various modules shown in system 600, reference may be made to the relevant descriptions of fig. 2-4 of the present specification.

Possible benefits of embodiments of the present description include, but are not limited to: (1) The radiotherapy auxiliary images corresponding to the current radiation fields in the multiple radiation fields in the single treatment process are acquired in real time to reconstruct the radiotherapy dosage in real time, the radiotherapy dosage for treatment can be fed back to doctors in real time, and the doctors can optimize the subsequent treatment plan by combining the radiotherapy dosage displayed in real time, so that the patients can be better treated; (2) The radiotherapy dosage is displayed in real time, so that a doctor can more actively perform subsequent operation under the condition that the doctor views the radiotherapy dosage of the treatment in time; (3) By evaluating the current radiation field or the treatment result by combining the two-dimensional passing rate, a doctor can intuitively know the treatment effect of the current radiation field or the treatment so as to adjust the subsequent treatment plan, thereby achieving the aim of better treating the patient.

It should be noted that, the advantages that may be generated by different embodiments may be different, and in different embodiments, the advantages that may be generated may be any one or a combination of several of the above, or any other possible advantages that may be obtained.

It should be appreciated that the system shown in fig. 6 and its modules may be implemented in a variety of ways. For example, in some embodiments, the system and its modules may be implemented in hardware, software, or a combination of software and hardware. Wherein the hardware portion may be implemented using dedicated logic; the software portions may then be stored in a memory and executed by a suitable instruction execution system, such as a microprocessor or special purpose design hardware. Those skilled in the art will appreciate that the methods and systems described above may be implemented using computer executable instructions and/or embodied in processor control code, such as provided on a carrier medium such as a magnetic disk, CD or DVD-ROM, a programmable memory such as read only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The system of the present specification and its modules may be implemented not only with 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., but also with software executed by various types of processors, for example, and with a combination of the above hardware circuits and software (e.g., firmware).

It should be noted that the above description of the medical image processing system and its modules is for descriptive convenience only and is not intended to limit the present description to the scope of the illustrated embodiments. It will be appreciated by those skilled in the art that, given the principles of the system, various modules may be combined arbitrarily or a subsystem may be constructed in connection with other modules without departing from such principles. For example, in some embodiments, the radiotherapy-assisted image acquisition module 610, the dose reconstruction module 620, and the real-time display module 630 may be different modules in a system, or may be one module that performs the functions of two or more modules described above. For example, each module may share one memory module, or each module may have a respective memory module. Such variations are within the scope of the present description.

While the basic concepts have been described above, it will be apparent to those skilled in the art that the foregoing detailed disclosure is by way of example only and is not intended to be limiting. Although not explicitly described herein, various modifications, improvements, and adaptations to the present disclosure may occur to one skilled in the art. Such modifications, improvements, and modifications are intended to be suggested within this specification, and therefore, such modifications, improvements, and modifications are intended to be included within the spirit and scope of the exemplary embodiments of the present invention.

Meanwhile, the specification uses specific words to describe the embodiments of the specification. Reference to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic is associated with at least one embodiment of the present description. Thus, it should be emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various positions in this specification are not necessarily referring to the same embodiment. Furthermore, certain features, structures, or characteristics of one or more embodiments of the present description may be combined as suitable.

Furthermore, those skilled in the art will appreciate that the various aspects of the specification can be illustrated and described in terms of several patentable categories or circumstances, including any novel and useful procedures, machines, products, or materials, or any novel and useful modifications thereof. Accordingly, aspects of the present description may be performed entirely by hardware, entirely by software (including firmware, resident software, micro-code, etc.), or by a combination of hardware and software. The above hardware or software may be referred to as a "data block," module, "" engine, "" unit, "" component, "or" system. Furthermore, aspects of the specification may take the form of a computer product, comprising computer-readable program code, embodied in one or more computer-readable media.

The computer storage medium may contain a propagated data signal with the computer program code embodied therein, for example, on a baseband or as part of a carrier wave. The propagated signal may take on a variety of forms, including electro-magnetic, optical, etc., or any suitable combination thereof. A computer storage medium may be any computer readable medium that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. Program code located on a computer storage medium may be propagated through any suitable medium, including radio, cable, fiber optic cable, RF, or the like, or a combination of any of the foregoing.

The computer program code necessary for operation of portions of the present description may be written in any one or more programming languages, including an object oriented programming language such as Java, scala, smalltalk, eiffel, JADE, emerald, C ++, c#, vb net, python, and the like, a conventional programming language such as C language, visual Basic, fortran 2003, perl, COBOL 2002, PHP, ABAP, a dynamic programming language such as Python, ruby, and Groovy, or other programming languages, and the like. The program code may execute entirely on the user's computer or as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may 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 the connection may be made to an external computer (for example, through the Internet), or the use of services such as software as a service (SaaS) in a cloud computing environment.

Furthermore, the order in which the elements and sequences are processed, the use of numerical letters, or other designations in the description are not intended to limit the order in which the processes and methods of the description are performed unless explicitly recited in the claims. While certain presently useful inventive embodiments have been discussed in the foregoing disclosure, by way of various examples, it is to be understood that such details are merely illustrative and that the appended claims are not limited to the disclosed embodiments, but, on the contrary, are intended to cover all modifications and equivalent arrangements included within the spirit and scope of the embodiments of the present disclosure. For example, while the system components described above may be implemented by hardware devices, they may also be implemented solely by software solutions, such as installing the described system on an existing server or mobile device.

Likewise, it should be noted that in order to simplify the presentation disclosed in this specification and thereby aid in understanding one or more inventive embodiments, various features are sometimes grouped together in a single embodiment, figure, or description thereof. This method of disclosure does not imply that the subject matter of the present description requires more features than are set forth in the claims. Indeed, less than all of the features of a single embodiment disclosed above.

In some embodiments, numbers describing the components, number of attributes are used, it being understood that such numbers being used in the description of embodiments are modified in some examples by the modifier "about," approximately, "or" substantially. Unless otherwise indicated, "about," "approximately," or "substantially" indicate that the number allows for a 20% variation. Accordingly, in some embodiments, numerical parameters set forth in the specification and claims are approximations that may vary depending upon the desired properties sought to be obtained by the individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and employ a method for preserving the general number of digits. Although the numerical ranges and parameters set forth herein are approximations that may be employed in some embodiments to confirm the breadth of the range, in particular embodiments, the setting of such numerical values is as precise as possible.

Each patent, patent application publication, and other material, such as articles, books, specifications, publications, documents, etc., referred to in this specification is incorporated herein by reference in its entirety. Except for application history documents that are inconsistent or conflicting with the content of this specification, documents that are currently or later attached to this specification in which the broadest scope of the claims to this specification is limited are also. It is noted that, if the description, definition, and/or use of a term in an attached material in this specification does not conform to or conflict with what is described in this specification, the description, definition, and/or use of the term in this specification controls.

Finally, it should be understood that the embodiments described in this specification are merely illustrative of the principles of the embodiments of this specification. Other variations are possible within the scope of this description. Thus, by way of example, and not limitation, alternative configurations of embodiments of the present specification may be considered as consistent with the teachings of the present specification. Accordingly, the embodiments of the present specification are not limited to only the embodiments explicitly described and depicted in the present specification.

Claims (10)

1. An on-line radiotherapy dose reconstruction method, the method comprising:

in a single treatment process of a target object, acquiring radiotherapy auxiliary images corresponding to the current radiation field in a plurality of radiation fields in real time;

Reconstructing a radiotherapy dosage in real time based on the radiotherapy auxiliary image corresponding to the current radiation field;

Displaying the radiotherapy dosage corresponding to the current radiation field in the treatment process in real time, or displaying the accumulation result of the radiotherapy dosages corresponding to the radiation fields in the treatment process in real time.

2. The method of claim 1, the method further comprising:

and comparing the real-time reconstructed radiotherapy dosage with the expected dosage, and determining a comparison result.

3. The method of claim 2, the method further comprising:

based on the comparison results, the result of the underdose/overdose analysis of the target region of rays or the ray-jeopardizing organ is given in real time.

4. The method of claim 2, the method further comprising:

And based on the comparison result, optimizing the treatment plan of the subsequent radiation fields of the current radiation field in the treatment process in real time.

5. The method of claim 2, the method further comprising:

and displaying the comparison result in a visual mode.

6. The method of claim 1, wherein reconstructing the radiation therapy dose in real-time based on the radiation therapy auxiliary image corresponding to the current radiation field comprises:

and responding to completion of the acquisition of the radiotherapy auxiliary image corresponding to the current field, and automatically reconstructing the radiotherapy dosage in real time based on the radiotherapy auxiliary image corresponding to the current field.

7. The method of claim 1, the method further comprising:

Transmitting the radiation therapy auxiliary image to a radiation therapy planning system to reconstruct the radiation therapy dose in real time on the radiation therapy planning system; and

And displaying the reconstruction result of the radiotherapy dosage in real time through a terminal device connected with the radiotherapy planning system.

8. The method of claim 1, the method further comprising:

Acquiring a two-dimensional passing rate based on the radiotherapy auxiliary image;

And determining an evaluation result of the current radiation field or the treatment result based on the two-dimensional passing rate and a radiation treatment dosage result corresponding to the current radiation field or a radiation treatment dosage result accumulated in the treatment process.

9. An on-line radiotherapy dose reconstruction system, the system comprising:

The radiotherapy auxiliary image acquisition module is used for acquiring the radiotherapy auxiliary images corresponding to the current radiation field in the multiple radiation fields in real time in the single treatment process of the target object;

The dose reconstruction module is used for reconstructing the radiotherapy dose in real time based on the radiotherapy auxiliary image corresponding to the current radiation field;

The real-time display module is used for displaying the radiotherapy dosage corresponding to the current radiation field in the treatment process in real time or displaying the accumulation result of the radiotherapy dosages corresponding to the radiation fields in the treatment process in real time.

10. An online radiotherapy dose reconstruction device comprising at least one storage medium for storing computer instructions and at least one processor; the at least one processor is configured to execute the computer instructions to implement the on-line radiotherapy dose reconstruction method of any one of claims 1-8.