JP7350520B2 - Medical processing equipment and radiation therapy equipment - Google Patents

Description

Embodiments of the present invention relate to medical processing devices and radiation therapy devices.

Prior to radiation therapy, there is a technique for correcting the patient's setup position and controlling the gate of radiation irradiation to the patient by confirming the location of the tumor. In order to confirm the location of the tumor, for example, a computed tomography (CT) device, an X-ray imaging device, an ultrasound diagnostic device, etc. are used.

Under these circumstances, when confirming the position of a tumor using a CT device and an X-ray imaging device, there is a problem in that the patient is exposed to radiation. On the other hand, when confirming the location of a tumor using an ultrasound diagnostic device, no radiation exposure occurs to the patient. However, images obtained by ultrasound diagnostic equipment (ultrasound images) are less accurate than images obtained by CT equipment or X-ray imaging equipment, and the difference in density due to tissue differences is small, so it is difficult to detect tumors. There is a problem that it is difficult to recognize the position.

Japanese Patent Application Publication No. 2003-117010 JP2017-035343A Japanese Patent Application Publication No. 2012-210232

The problem to be solved by the invention is to estimate the tumor position using ultrasound images.

The medical processing device according to the embodiment includes an acquisition section and an estimation section. The acquisition unit acquires blood flow information based on ultrasound Doppler analysis regarding a region including a tumor during a treatment stage of radiotherapy. The estimating unit calculates the current blood vessel position based on the current blood vessel position specified from the acquired blood flow information and the positional relationship between the blood vessel included in the region and the tumor at the planning stage of the radiotherapy. Estimate the tumor location.

FIG. 1 is a diagram illustrating an example of the configuration of a radiation therapy system according to an embodiment. FIG. 2 is a diagram showing an example of the configuration of the treatment support device shown in FIG. 1. FIG. 3 is a flowchart showing an example of the flow of identifying the positional relationship between a tumor and a blood vessel, which is carried out in the planning stage in the radiation therapy system of FIG. 1. FIG. 4 is a diagram for explaining the identification of the positional relationship between a tumor and a blood vessel in the flow of FIG. 3. FIG. 5 is a flowchart illustrating an example of the flow of estimating the current tumor position using ultrasound images, which is performed during the treatment stage in the radiation therapy system of FIG. 1. FIG. 6 is a diagram for explaining estimation of the current tumor position using ultrasound images in the flow of FIG. FIG. 7 is a diagram showing an example of an image displayed in the flow of FIG. FIG. 8 is a diagram for explaining a case where the positional relationship between a tumor and each of a plurality of blood vessels is specified. FIG. 9 is a diagram for explaining a case where the positional relationship between the risk organ and the blood vessel is further specified.

Hereinafter, a treatment support device and a radiation therapy system according to the present embodiment will be described with reference to the drawings.

In the following description, components having the same or substantially the same functions as those described above with respect to the existing figures are denoted by the same reference numerals, and will be described repeatedly only when necessary. Furthermore, even when the same part is shown, the dimensions and ratios may be shown differently depending on the drawing.

FIG. 1 is a diagram showing an example of the configuration of a radiation therapy system 1 according to the present embodiment. As shown in FIG. 1, a radiation therapy system 1 includes a treatment planning CT device 2, an ultrasound diagnostic device 3, a treatment planning device 4, a radiation therapy device 5, and a treatment support device 6, which are connected to each other via a network. have Here, the treatment support device 6 is an example of a medical processing device.

Note that the movement of various data between the treatment planning CT device 2, ultrasound diagnostic device 3, treatment planning device 4, radiation therapy device 5, and treatment support device 6 is not limited to the case where it is performed via a network, It may also be performed via a memory or the like. In this case, each device included in the radiation therapy system 1 does not need to be connected to other devices via a network.

The treatment planning CT device 2 is an X-ray computed tomography device for generating CT images used for radiation treatment planning. For example, the treatment planning CT device 2 irradiates the patient with X-rays from the X-ray tube while rotating a rotating frame holding an X-ray tube and an X-ray detector at high speed, and converts the X-rays that have passed through the patient into X-rays. Detected by a line detector. When taking a CT image for treatment planning, the patient is in a state of being fixed to the imaging top plate or the like of the CT apparatus 2 for treatment planning using a fixture. The imaging top plate of the treatment planning CT device 2 has a planar shape similar to the treatment top plate of the radiation therapy device 5 in order to prevent the patient's position from changing between CT imaging and radiation therapy. are doing. In order to improve patient positioning accuracy, the imaging top plate preferably has the same shape as the treatment top plate.

The console of the CT apparatus 2 for treatment planning includes a computer including a processor such as a Central Processing Unit (CPU), memory such as Read Only Memory (ROM) and Random Access Memory (RAM), a display, an input interface, and a communication interface. The console reconstructs three-dimensional CT image data (X-ray CT image) based on raw data (projection data) from the X-ray detector. The X-ray CT image may be image data that expresses the spatial distribution of the X-ray attenuation coefficient of a substance on the transmission path of the X-ray, or may express the spatial distribution of CT values according to the X-ray attenuation coefficient. It may also be image data. The X-ray CT image generated by the treatment planning CT device 2 is also called a treatment planning CT image. The generated CT image for treatment planning is transmitted to the treatment planning device 4 and/or the treatment support device 6.

Note that although the radiation therapy system 1 includes the treatment planning CT device 2, the present embodiment is not limited to this. That is, the radiation therapy system 1 may be a cone beam CT device or magnetic resonance imaging (MRI) device instead of the treatment planning CT device 2, as long as it is a medical image diagnostic device that can generate three-dimensional medical image data for patient treatment planning. ) device, nuclear medicine diagnostic device, etc. However, in order to specifically explain the following, the radiation therapy system 1 is a medical image diagnostic apparatus that can generate three-dimensional medical image data for patient treatment planning (medical image data for treatment planning). It is assumed that the device has a device 2.

The ultrasonic diagnostic apparatus 3 transmits ultrasonic waves into the patient via an ultrasonic probe, and also receives ultrasonic waves reflected within the patient's body. The ultrasonic diagnostic apparatus 3 includes a processor such as a CPU, a memory such as a ROM or a RAM, a display, an input interface, and a communication interface. The ultrasound diagnostic apparatus 3 performs signal processing on echo signals corresponding to received ultrasound waves to generate ultrasound images. As the signal processing, for example, B-mode processing and Doppler processing are used. The ultrasonic diagnostic apparatus 3 generates a B-mode image expressing the spatial distribution of the acoustic impedance difference within the patient by performing B-mode processing on the echo signal. The ultrasound diagnostic device 3 generates a blood flow information image expressing the spatial distribution of blood flow motion information (hereinafter referred to as blood flow information) within the patient by performing Doppler processing (ultrasonic Doppler analysis) on the echo signal. .

In the B-mode processing, the ultrasonic diagnostic apparatus 3 performs envelope detection processing, logarithmic amplification processing, etc. on the received signal to generate B-mode data. The generated B-mode data is stored in a RAW data memory (not shown) as B-mode RAW data on an ultrasonic scanning line (raster). In Doppler processing, the ultrasound diagnostic apparatus 3 performs frequency analysis on the received signal to generate Doppler data of the moving object. The moving object is, for example, blood flow or tissue contained within the subject. Average speed, average variance value, average power value, etc. are calculated as motion information of the moving object. These motion information are calculated for each of a plurality of sample points set within a region of interest (ROI) to be subjected to Doppler processing. The generated Doppler data is stored in a RAW data memory (not shown) as Doppler RAW data on an ultrasound scanning line. In the Doppler process, the ultrasound diagnostic apparatus 3 is capable of executing a color Doppler method such as a color flow mapping (CFM) method. In the CFM method, ultrasonic waves are transmitted and received multiple times on multiple scanning lines. The ultrasonic diagnostic apparatus 3 extracts signals originating from blood flow, tissues, etc. by applying a Moving Target Indicator (MTI) filter to a data string at the same position. The ultrasonic diagnostic apparatus 3 estimates motion information such as velocity, dispersion, or power of blood flow or tissue from the extracted signals.

The ultrasound diagnostic apparatus 3 generates an image based on data generated by B-mode processing and Doppler processing. For example, the ultrasonic diagnostic apparatus 3 converts (scan convert) a scanning line signal sequence of ultrasonic scanning into a scanning line signal sequence of a video format typified by a television or the like, and generates an image for display. When a two-dimensional scan is performed, the ultrasound diagnostic apparatus 3 generates a two-dimensional image regarding the scan plane. When a three-dimensional scan is performed, the ultrasound diagnostic apparatus 3 generates three-dimensional image data regarding the scan area, and performs arbitrary three-dimensional image processing on the three-dimensional image data to generate a two-dimensional image. . As the three-dimensional image processing, Multi-Planer Reconstruction (MPR) processing, volume rendering, surface rendering, pixel value projection processing, and Curved MPR (CPR) processing may be used.

Specifically, the ultrasound diagnostic apparatus 3 performs RAW-pixel conversion or RAW-voxel conversion on the B-mode RAW data stored in the RAW data memory, thereby creating a two-dimensional or three-dimensional B-mode image. generate. Further, the ultrasound diagnostic apparatus 3 performs RAW-pixel conversion or RAW-voxel conversion on the Doppler RAW data stored in the RAW data memory, thereby providing a two-dimensional or three-dimensional image of blood flow or tissues. Generate dimensional Doppler images. The Doppler image includes a velocity image, a dispersion image, a power image, or a combination thereof. Hereinafter, the two-dimensional B-mode image and the two-dimensional Doppler image will be collectively referred to simply as an ultrasound image. The ultrasonic diagnostic apparatus 3 may combine text information of various parameters, scales, body marks, etc. with the generated image.

The treatment planning device 4 is a computer including a processor such as a CPU, a memory such as a ROM or a RAM, a display, an input interface, and a communication interface. The treatment planning device 4 receives treatment planning CT images from the treatment planning CT device 2 directly or via Picture Archiving and Communication Systems (PACS). The treatment planning device 4 creates a radiation treatment plan for the patient based on the received treatment planning CT image. When creating a radiation treatment plan (planning time), the tumor position is specified, for example, based on a user's input in response to a treatment planning CT image displayed on a display. The created radiation treatment plan and the identified tumor position are supplied to the radiation treatment device 5 and the treatment support device 6, respectively.

There are two methods for creating a radiation treatment plan: forward planning and inverse planning. Forward planning involves setting detailed radiation treatment conditions such as the number of irradiation directions, each irradiation angle, the radiation intensity for each irradiation, the collimator opening for each irradiation, and the wedge filter. Evaluate the radiation treatment conditions by looking at the resulting radiation distribution. When changing the radiation distribution, change some or all of the radiation treatment conditions and calculate the radiation distribution again. In this way, in forward planning, the radiation distribution is changed little by little while changing the radiation treatment conditions, and the radiation conditions are changed repeatedly until the desired radiation distribution is achieved. Inverse planning sets the tumor area and appropriate margins, and sets the radiation dose and tolerance to irradiate the area. Further, risk areas such as dangerous organs are extracted from the CT image for treatment planning, and the radiation dose to the risk area is set to a safe level that does not exceed a predetermined level of radiation dose. The treatment planning device 4 sequentially creates a radiation treatment plan that satisfies the requirements for this radiation distribution while changing the radiation treatment conditions.

The radiation therapy device 5 is a device that treats a patient by irradiating a target tumor or the like within the patient with radiation according to a radiation therapy plan. Specifically, the radiation therapy apparatus 5 includes a treatment gantry, a treatment bed, and a console. The treatment pedestal supports the irradiation head rotatably around the rotation axis. The irradiation head is equipped with an acceleration tube that accelerates electrons generated by an electron gun or the like, and a metal target with which the electrons accelerated by the acceleration tube collide. When electrons collide with a metal target, X-rays, a type of radiation, are generated. The irradiation head irradiates radiation according to the radiation treatment plan planned by the treatment planning device 4. The point where the beam axis of the radiation from the irradiation head and the rotation axis intersect is spatially fixed and is called the isocenter. The treatment bed includes a treatment top plate on which a patient is placed, and a base that movably supports the treatment top plate. The treatment top plate has a planar shape similar to the imaging top plate. The treatment pedestal, treatment bed, and patient are aligned so that the treatment area of the patient is aligned with the isocenter. Here, the irradiation head is an example of an irradiation unit.

The treatment support device 6 is a computer for supporting radiation treatment planning or radiation treatment. The treatment support device 6 is included in, for example, an information system that manages radiation therapy schedule information, radiation therapy plan information, medical images, and the like. For example, Oncology Information System (OIS) is known as such an information system. For example, the treatment support device 6 supplies a radiation treatment plan to the radiation treatment device 5. In addition, as will be described later, the treatment support device 6 estimates the current tumor position based on the ultrasound image, calculates the amount of deviation between the estimated tumor position and the planned tumor position, and calculates the amount of deviation between the estimated tumor position and the planned tumor position. patient position correction and/or gate control of the irradiation depending on the amount. The amount of deviation indicates, for example, the direction and/or magnitude of the deviation.

Here, an example of the configuration of the treatment support device 6 will be described with reference to the drawings. FIG. 2 is a diagram showing an example of the configuration of the treatment support device shown in FIG. 1. As shown in FIG. 2, the treatment support device 6 includes a processing circuit 61, an image processing circuit 62, a communication interface 63, a display device 64, an input interface 65, and a storage circuit 66. The processing circuit 61, the image processing circuit 62, the communication interface 63, the display device 64, the input interface 65, and the storage circuit 66 are communicably connected to each other via a bus.

The processing circuit 61 includes a processor such as a CPU, a Micro Processing Unit (MPU), or a Graphics Processing Unit (GPU), and a memory such as a ROM or RAM as hardware resources. The processing circuit 61 executes a program related to radiation therapy support (hereinafter referred to as a treatment support program), and performs an acquisition function 611, a position estimation function 612, a deviation amount calculation function 613, a patient position correction function 614, a gate control function 615, and A display control function 616 is realized.

In the acquisition function 611, the processing circuit 61 acquires various information necessary for estimating the current tumor position, etc. regarding the patient to be treated with radiation therapy. For example, in the planning stage of radiation therapy, the processing circuit 61 acquires an X-ray CT image regarding a region including a tumor from the treatment planning CT device 2, acquires the tumor position from the treatment planning device 4, and acquires the tumor position from the ultrasound diagnostic device 3. An ultrasound image (blood flow information image and B-mode image) regarding the region including the tumor is acquired from the image. For example, in the treatment stage of radiotherapy, the processing circuit 61 acquires an ultrasound image (blood flow information image and B-mode image) regarding a region including a tumor from the ultrasound diagnostic apparatus 3, and stores it from the storage circuit 66 in the treatment stage of radiation therapy. and obtain the positional relationship of the tumor. Note that if some or all of the various types of information described above are stored in advance in the storage circuit 66, the processing circuit 61 acquires various types of information from the storage circuit 66 at each stage. Here, the processing circuit 61 that implements the acquisition function 611 is an example of an acquisition unit.

In the position estimation function 612, the processing circuit 61 specifies the blood vessel position on the B-mode image from the blood flow information. The processing circuit 61 may identify the tumor position on the treatment planning CT image. The processing circuit 61 identifies the positional relationship between the blood vessel and the tumor by aligning the B-mode image and the CT image for treatment planning. The processing circuit 61 estimates the current tumor position based on the current blood vessel position specified from the blood flow information at the treatment stage and the positional relationship at the planning stage. Here, the processing circuit 61 that implements the position estimation function 612 is an example of an estimator.

In the deviation amount calculation function 613, the processing circuit 61 calculates the deviation amount between the current tumor position estimated at the treatment stage and the tumor position at the time of planning (planning stage). Here, the processing circuit 61 that implements the deviation amount calculation function 613 is an example of a calculation section.

In the patient position correction function 614, the processing circuit 61 corrects the target patient's setup position according to the calculated amount of deviation. Here, the processing circuit 61 that implements the patient position correction function 614 is an example of a correction section.

In the gate control function 615, the processing circuit 61 performs gate control of the radiation therapy according to the calculated amount of deviation. Here, the processing circuit 61 that implements the gate control function 615 is an example of a control section.

In the display control function 616, the processing circuit 61 displays various information on the display device 64. Specifically, the processing circuit 61 sends image data such as an operation screen, aligned CT images and ultrasound images for treatment planning (superimposed images), and images presenting the calculated amount of deviation to the image processing circuit 62. Generate. The processing circuit 61 displays various generated images on the display device 64. Here, the processing circuit 61 that implements the display control function 616 can be expressed as an example of a generation unit.

Note that the processing circuit 61 may be realized by an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA). Further, the processing circuit 61 may be realized by another complex programmable logic device (CPLD) or simple programmable logic device (SPLD).

Note that each of the functions 611 to 616 is not limited to being implemented by a single processing circuit. A processing circuit may be configured by combining a plurality of independent processors, and the functions 611 to 616 may be realized by each processor executing a program.

Image processing circuit 62 generates various images. The image processing circuit 62 includes a processor such as a GPU and a memory such as a ROM or RAM as hardware resources. Further, the image processing circuit 62 performs various types of image processing on various acquired or generated images. The image processing circuit 62 generates image data such as an operation screen, aligned CT images and ultrasound images for treatment planning (superimposed images), and images presenting the calculated amount of deviation. The image processing circuit 62 can also perform three-dimensional image processing on a three-dimensional image to generate a two-dimensional image. As the three-dimensional image processing, rendering such as volume rendering, surface rendering, pixel value projection processing, MPR processing, and CPR processing may be used. Note that the image processing circuit 62 may be configured as a part of the processing circuit 61, for example. Here, the image processing circuit 62 can be expressed as an example of a generating section.

The communication interface 63 performs data communication with the treatment planning CT device 2, ultrasound diagnostic device 3, treatment planning device 4, and radiation therapy device 5 included in the radiation therapy system 1 via a wired or wireless connection (not shown). .

The display device 64 displays various information using a display control function 616. The display device 64 can be, for example, a CRT display, a liquid crystal display, an organic EL display, an LED display, a plasma display, or any other display known in the art. The display device 64 may be a projector.

Specifically, the input interface 65 includes an input device and an input interface circuit. The input device receives various commands from the user. As input devices, a keyboard, mouse, various switches, etc. can be used. Output signals from the input devices are supplied to the processing circuit 61 via the input interface circuit.

The storage circuit 66 is a storage device such as a hard disk drive (HDD), solid state drive (SSD), or integrated circuit storage device that stores various information. Further, the storage circuit 66 may be a drive device or the like that reads and writes various information to/from a portable storage medium such as a CD-ROM drive, a DVD drive, or a flash memory. For example, the memory circuit 66 stores information such as treatment support programs, X-ray CT images, ultrasound images (B-mode images and blood flow information images), tumor positions, blood vessel positions, positional relationships between blood vessels and tumors, and deviations in tumor positions. Memorize the amount, etc. The storage circuit 66 may store various types of data being processed.

An example of the operation of the radiation therapy system 1 according to this embodiment will be described below.

<Overview of operation example>
In the radiation treatment planning stage, a radiation treatment plan is created based on the treatment planning CT image. Further, the positional relationship between the blood vessel position specified from the ultrasound image and the tumor position specified from the treatment planning CT image at the time of planning is specified.

In the treatment stage of radiation therapy, multiple treatments are performed over a predetermined period of time. At the time of each treatment, the tumor position at that time is estimated based on newly acquired ultrasound images. Furthermore, the amount of deviation between the estimated tumor position and the planned tumor position is calculated. The calculated amount of deviation is used to correct the patient's setup position (patient position correction) before treatment (before the start of irradiation). Further, the calculated amount of deviation is used for gate control of irradiation during treatment (after the start of irradiation).

Note that during a plurality of treatments, the radiation treatment plan may be changed (re-planned) based on newly acquired treatment planning CT images. That is, the treatment phase may include a replanning phase. In the replanning stage, the positional relationship between the blood vessel position and the tumor position is identified in the same way as in the planning stage described above, based on the CT images and ultrasound images for treatment planning newly collected at the time of replanning. That's fine. In addition, in the treatment stage performed after the re-planning stage, based on the positional relationship specified in the re-planning stage, tumor position estimation, deviation amount calculation, patient position correction, etc. and gate control may be implemented.

In this embodiment, the relative positional relationship between the blood vessel position specified in the planning stage and the tumor position is used to estimate the tumor position in the treatment stage from the blood vessel position identified in the treatment stage. This is based on the empirical rule that the relative positional relationship between the tumor position and the surrounding blood vessel positions is approximately unchanged. A relatively large blood vessel is preferably used as a reference for estimating the tumor position. Such blood vessels are present in the lung fields, liver, kidneys, prostate, and in or around the neck itself. Therefore, in this embodiment, tumors occurring in the lung field, liver, kidney, prostate, and neck are targeted for treatment.

<Example of operation at planning stage>
Here, an example of the operation of the radiotherapy system 1 in the planning stage of radiotherapy will be described in more detail with reference to the drawings. FIG. 3 is a flowchart showing an example of the flow of identifying the positional relationship between a tumor and a blood vessel, which is carried out in the planning stage in the radiation therapy system 1 of FIG. FIG. 4 is a diagram for explaining the identification of the positional relationship between a tumor and a blood vessel in the flow of FIG. 3.

In step S11, the tumor is imaged by the treatment planning CT device 2. The treatment planning CT device 2 generates a treatment planning CT image regarding a region including a tumor. The generated CT image for treatment planning is supplied to the treatment planning device 4 and the treatment support device 6.

In step S12, the ultrasound diagnostic device 3 performs imaging of the tumor. The ultrasound diagnostic apparatus 3 generates an ultrasound image I10 regarding a region including a tumor. Here, the ultrasound image I10 includes a B-mode image I11 and a blood flow information image I12. The generated ultrasound image I10 is supplied to the treatment support device 6.

In step S13, the treatment planning device 4 creates a treatment plan based on the treatment planning CT image. The treatment planning device 4 supplies information regarding the tumor position specified from the treatment planning CT image at the time of planning to the treatment support device 6.

In step S14, the blood vessel position PB is specified from the ultrasound image I10. In the treatment support device 6, a processing circuit 61 that implements an acquisition function 611 acquires an ultrasound image I10 regarding a region including a tumor from the ultrasound diagnostic device 3. The display control function 616 displays at least the blood flow information image I12 of the acquired ultrasound images I10 on the display device 64. The processing circuit 61 that implements the position estimation function 612 identifies the blood vessel position PB in the region including the tumor based on the acquired blood flow information image I12. In other words, the processing circuit 61 identifies the blood vessel position PB in the B-mode image I11. The blood vessel position PB is specified, for example, based on the user's input according to the displayed blood flow information image I12. The identified blood vessel position PB may be stored in the storage circuit 66.

Note that the identification of the blood vessel position PB may be performed by the processing circuit 61, for example, based on a comparison between the value of the blood flow information and a predetermined threshold value that is set in advance and stored in the storage circuit 66. More specifically, the processing circuit 61 searches for pixels having blood flow information values exceeding a predetermined threshold, and specifies a set of the pixels as the blood vessel position PB. The outer shape of the set of pixels (the outer shape of the blood vessel) may be defined as the blood vessel position PB, or the representative point such as the center of gravity or the center of the set of pixels may be defined as the blood vessel position PB, or at least two It may also be defined by representative points.

In step S15, the processing circuit 61 that implements the acquisition function 611 acquires a treatment planning CT image from the treatment planning CT apparatus 2. The processing circuit 61 acquires the tumor position PT specified at the time of planning from the treatment planning device 4. The processing circuit 61 that implements the position estimation function 612 aligns the treatment planning CT image and the B-mode image I11 (ultrasound image). The aligned treatment planning CT image and B-mode image I11 are displayed in a superimposed manner. Image data for superimposed display is generated by the image processing circuit 62, for example. The superimposed display is performed, for example, by displaying the identified tumor position PT on the ultrasound image I10, as shown in FIG.

Note that the superimposed display may be performed by displaying the specified blood vessel position PB on the treatment planning CT image.

Note that the treatment planning CT image is not limited to being acquired from the treatment planning CT apparatus 2, and may be acquired from the treatment planning apparatus 4 together with the tumor position PT.

Note that the tumor position PT may be specified by the treatment support device 6. In this case, the processing circuit 61 that implements the position estimation function 612 specifies the tumor position PT from the acquired treatment planning CT image in the same way as the processing circuit of the treatment planning device 4. In this case, the processing circuit 61 that implements the acquisition function 611 does not need to acquire the tumor position PT specified at the time of planning from the treatment planning device 4.

In step S16, the processing circuit 61 that implements the position estimation function 612 specifies the positional relationship RBT between the specified blood vessel position PB and the tumor position PT in the region including the tumor. Information regarding the identified positional relationship RBT is stored in the storage circuit 66. At this time, alignment information of the treatment planning CT image and the B-mode image I11 may be further stored. After that, the flow of identifying the positional relationship ends.

<Example of operation at treatment stage>
Here, an example of the operation of the radiotherapy system 1 in the treatment stage of radiotherapy will be described in more detail with reference to the drawings. FIG. 5 is a flowchart showing an example of the flow of estimating the current tumor position PTb using the ultrasound image I20, which is performed in the treatment stage in the radiation therapy system 1 of FIG. FIG. 6 is a diagram for explaining estimation of the current tumor position PTb using the ultrasound image I20 in the flow of FIG.

In step S21, imaging of the tumor during treatment by the ultrasound diagnostic apparatus 3 is performed in the same manner as in step S11 in the planning stage.

In step S22, the processing circuit 61 that implements the acquisition function 611 acquires an ultrasound image I20 regarding the region including the tumor from the ultrasound diagnostic apparatus 3. The acquired ultrasound image I20 includes a B-mode image I21 and a blood flow information image I22. The display control function 616 displays at least the B-mode image I21 of the acquired ultrasound images I20 on the display device 64. The processing circuit 61 that implements the position estimation function 612 estimates (tentatively estimates) the tumor position PTa within the region including the tumor based on the acquired B-mode image I21. In other words, the processing circuit 61 tentatively estimates the tumor position PTa in the B-mode image I21. The tentative estimation of the tumor position PTa is performed, for example, based on the user's input according to the displayed B-mode image I21. The tentatively estimated current tumor position PTa may be stored in the storage circuit 66.

Note that the temporary estimation of the tumor position PTa may be performed, for example, by the processing circuit 61 or the image processing circuit 62 performing image processing such as edge detection on the B-mode image I21.

Note that the tentative estimation of the tumor position PTa may be defined by the outer shape of the detected tumor, the position of its center of gravity, or by setting at least two representative points.

In step S23, the blood vessel position PB is specified from the ultrasound image I20 in the same manner as step S14 in the planning stage. The identified current blood vessel position PB may be stored in the storage circuit 66.

In step S24, the processing circuit 61 that implements the acquisition function 611 acquires the positional relationship RBT at the planning stage from the storage circuit 66. The processing circuit 61 that implements the position estimation function 612 corrects the tumor position PTa provisionally estimated in step S22 based on the current blood vessel position PB specified in step S23 and the positional relationship RBT in the planning stage. In the example shown in FIG. 6, the position of the tentatively estimated tumor position PTa has been corrected as indicated by arrow AC.

As explained above, the treatment support device 6 uses the current blood vessel position PB specified from the acquired blood flow information image I22 (blood flow information) and the radiation therapy planning stage through the flow of steps S22 to S24. The current tumor position PTb is estimated based on the positional relationship RBT between the blood vessel and the tumor. The estimated current tumor position PTb may be stored in the storage circuit 66.

As described above, according to the radiation therapy system 1 according to the present embodiment, the relative positional relationship between the blood vessel position specified in the planning stage and the tumor position is used to calculate the relevant position from the blood vessel position identified in the treatment stage. Estimate the tumor location at the treatment stage. Therefore, there is an effect that the current tumor position can be estimated using the ultrasound image without newly acquiring CT images for treatment planning. In addition, since the relative positional relationship between the blood vessel position and tumor position specified in the planning stage is used, the tumor position can be estimated more easily than when estimating the tumor position using only B-mode images or blood flow information images. Can be grasped with high accuracy. In other words, according to the technology according to the present embodiment, the user can accurately grasp the tumor position, which is difficult to judge from ultrasound images alone, without increasing radiation exposure to the patient.

In step S25, the deviation amount calculation function 613 calculates the deviation amount between the estimated current tumor position PTb and the tumor position PT at the time of planning (planning stage). The calculated amount of deviation may be stored in the storage circuit 66.

As described above, according to the technology according to the present embodiment, the amount of deviation between the tumor position specified at the time of treatment planning and the current tumor position can be calculated without newly collecting CT images for treatment planning. There is an effect.

In step S26, patient position correction or irradiation gate control is performed according to the calculated amount of deviation. Patient position correction and irradiation gate control according to the calculated amount of deviation will be described later.

The flow from step S21 to step S26 is repeated as appropriate until the patient position correction or irradiation gate control in step S26 is completed, and ends when the patient position correction or irradiation gate control is completed.

Here, the patient position correction or irradiation gate control performed in step S26 will be described with reference to the drawings. FIG. 7 is a diagram showing an example of a display image I30 displayed in the flow of FIG.

(before treatment)
First, a case will be described in which the flow from step S21 to step S26 is performed before treatment (at the time of treatment). In this case, in step S26, the calculated amount of deviation is presented to the user. The presentation to the user is performed, for example, by display, but may also be performed by audio. The user performs patient position correction according to the presented amount of deviation. In other words, in this step performed before treatment, patient position correction is performed according to the calculated amount of deviation.

The processing circuit 61 that implements the patient position correction function 614 calculates parameter values according to the calculated amount of deviation. The parameter may be any value or symbol that allows the user to determine the positional relationship between the current tumor position and the planned tumor position. In other words, the parameter may be any value or symbol that allows the user to determine whether the patient's setup position is appropriate. The parameters include, for example, the amount of operation of the treatment top plate (the amount of user operation, the amount of movement). The symbols include, for example, characters and marks indicating the operating direction of the treatment top plate and whether or not it is appropriate. The image processing circuit 62 generates a parameter display image I50 that displays parameters. The processing circuit 61 that implements the display control function 616 displays the generated parameter display image I50 on the display device 64. That is, the calculated amount of deviation is presented to the user as a parameter value or symbol. For example, the user moves the treatment top according to the displayed parameter values or symbols.

As described above, according to the technology according to the present embodiment, the patient's treatment site (tumor position) can be aligned with the isocenter of the radiation therapy device 5 using only ultrasound images without increasing radiation exposure to the patient. It has the effect of being able to

Note that the processing circuit 61 that implements the patient position correction function 614 may determine whether or not the amount of deviation (size, direction) can be achieved by moving the treatment top plate. When it is determined that the amount of deviation is not the amount that can be achieved by moving the treatment top, the processing circuit 61 may notify the user. The notification may be made by voice or by display. The notification may be one that prompts reinstallation of the fixing device, one that prompts correction of the probe position of the ultrasonic diagnostic device 3, or one that prompts re-planning of the radiation treatment plan. Good too.

Note that the movement of the treatment top plate is not limited to user operation according to the display, but may be realized by control of the processing circuit 61 according to the calculated amount of deviation. In this case, the patient position correction function 614 may calculate, for example, the amount of movement of the treatment top plate as the value of the parameter according to the calculated amount of deviation. The processing circuit 61 generates a control signal for moving the treatment top according to the calculated movement amount. The generated control signal is supplied to the radiation therapy device 5.

(If undergoing treatment)
Next, a case will be described in which the flow from step S21 to step S26 is performed during treatment (at the time of treatment). In this case, in step S26, the calculated amount of deviation is presented to the user. The presentation to the user is performed, for example, by display, but may also be performed by audio. The user performs irradiation gate control according to the presented amount of deviation. In other words, in this step performed during treatment, gate control of irradiation is performed according to the calculated amount of deviation.

The processing circuit 61 that implements the gate control function 615 calculates the value of the parameter according to the calculated amount of deviation. The parameter may be any value that allows the user to determine the positional relationship between the current tumor position and the planned tumor position. In other words, the parameter may be any value that allows the user to determine when to start (resume) or end (stop) irradiation during treatment. The parameters include, for example, the magnitude of the deviation and a predetermined threshold. The parameter may be, for example, a difference value between a predetermined threshold value and the magnitude of the shift, or a value indicating whether the magnitude of the shift is within a predetermined threshold range. The image processing circuit 62 generates a parameter display image I50 that displays parameters. The processing circuit 61 that implements the display control function 616 displays the generated parameter display image I50 on the display device 64. That is, the calculated amount of deviation is presented to the user as a parameter value. For example, the user instructs to start (resume) or end (stop) irradiation according to the displayed parameter value.

As described above, the technology according to the present embodiment has the effect that gate control of irradiation can be realized using only ultrasound images without increasing radiation exposure to the patient. In other words, the technique according to this embodiment has the effect of reducing radiation irradiation to other parts of the treatment site (tumor position).

Note that the calculated amount of deviation is presented to the user not only by parameters, but also by a display indicating whether the size of the deviation is within a predetermined threshold range or not, and whether or not it is the irradiation timing. Good too. This display may be performed simply by displaying "ON" or "OFF", or by changing the displayed color depending on whether or not it is the irradiation timing.

Note that the gate control of irradiation is not limited to the user's instruction operation according to the display, but may be realized by the control of the processing circuit 61 according to the calculated amount of deviation. In this case, the processing circuit 61 that implements the gate control function 615 determines, for example, whether the magnitude of the deviation is within a predetermined threshold range.

For example, when it is determined that the magnitude of the deviation is not within a predetermined threshold range, the processing circuit 61 prevents irradiation from starting (resuming) even if a user operation instructing to start (resuming) irradiation is performed. A control signal is generated to control the irradiation, or to terminate (stop) the irradiation if it is currently being irradiated. The generated control signal is supplied to the radiation therapy device 5.

For example, after the user instructs to start irradiation, the processing circuit 61 may generate a control signal instructing to start irradiation according to the calculated amount of deviation. Thereafter, the processing circuit 61 generates a control signal for stopping or restarting irradiation according to the calculated amount of deviation.

Note that either one of patient position correction and irradiation gate control may not be performed.

Note that the display image I30 displayed during treatment (before and/or during treatment) may include an ultrasound image I40, as shown in FIG. As the ultrasound image I40, a B-mode image I41 may be used, or a blood flow information image I42 may be further used.

Note that the display image I30 displayed during treatment (before and/or during treatment) may include the estimated current tumor position PTb, as shown in FIG. Further, the calculated deviation amount may be presented to the user not only by parameters but also by an arrow AS indicating the deviation amount (size, direction).

Note that the display image I30 displayed at the time of treatment (before and/or during treatment) may further display the tumor position PTc at the time of planning, as shown in FIG. At this time, it can be said that the display of the estimated current tumor position PTb and the planned tumor position PTc corresponds to the display of the calculated deviation amount. That is, the calculated deviation amount may be presented to the user not only by the parameters but also by displaying the current tumor position PTb and the tumor position PTc at the time of planning.

Note that, as shown in FIG. 7, the display image I30 displayed during treatment (before and/or during treatment) includes a graph display image I60 showing the change over time (time-series change) in the amount of deviation. It's okay. For example, there may be periodic displacement of tumor location. In this case, by displaying the temporal change in the amount of deviation and the threshold value (dashed line in FIG. 7), the user can determine when the estimated current tumor position and the planned tumor position match or can be considered to match. can be presented to. In addition, if there is a periodic displacement in the amount of deviation, for example, when correcting the patient position before treatment, the tumor position corresponding to breath holding, the average value (median value) of the tumor position, etc. It may also be used as a location.

<When the positional relationship between the tumor and each of multiple blood vessels is specified>
In addition, in the flow of specifying the positional relationship between a tumor and a blood vessel described above with reference to FIG. 3, the positional relationship may be specified between a tumor and a plurality of blood vessels. FIG. 8 is a diagram for explaining a case where the positional relationship between a tumor and each of a plurality of blood vessels is specified. FIG. 8 shows a plurality of blood vessel positions PB1 and PB2 (first blood vessel position and second blood vessel position) identified from the blood flow information image I72 (ultrasound image I70), and a B-mode image I71 (ultrasound image I70) The tumor position PT is shown superimposed on the top. As shown in FIGS. 3 and 8, after a plurality of blood vessel positions PB1 and PB2 are specified in step S14, a plurality of positional relationships RBT1 and RBT2 regarding the plurality of blood vessel positions PB1 and PB2 are respectively specified in step S16. Ru. In the example shown in FIG. 8, each of the positional relationships RBT1 and RBT2 is a positional relationship between each of the blood vessel positions PB1 and PB2 and the tumor position PT.

In addition, although the case where the positional relationship with respect to a tumor is specified regarding each of the several blood vessels detected in one ultrasound image regarding the area|region containing a tumor was demonstrated as an example, it is not limited to this. Regarding a plurality of blood vessels detected in a plurality of ultrasound images related to a region including a tumor, the positional relationship with respect to the tumor may be specified.

According to these configurations, in addition to the effects obtained in the above-described embodiments, there is an effect that the accuracy of specifying the tumor position can be improved.

<When the positional relationship between risk organs and blood vessels is further specified>
In addition, in the flow of specifying the positional relationship between a tumor and a blood vessel described above with reference to FIG. 3, the positional relationship between a risk organ and a blood vessel may be further specified. FIG. 9 is a diagram for explaining a case where the positional relationship between the risk organ and the blood vessel is further specified. FIG. 9 shows the blood vessel position PB identified from the blood flow information image I82 (ultrasound image I80), the tumor position PT and the risk organ position PR superimposed on the B-mode image I81 (ultrasound image I80). It is shown. As shown in FIGS. 3 and 9, in step S13, after the risk organ position PR identified from the CT image for treatment planning at the time of planning is further acquired from the treatment planning device 4, the positional relationship RBT regarding the tumor position PT is identified. Similarly, the positional relationship RBR between the blood vessel position PB and the risk organ position PR is further specified. After that, using the positional relationship RBR between the blood vessel position PB and the risk organ position PR, the current risk organ position PR is estimated, the amount of deviation of the risk organ position PR is calculated, and the calculation is performed according to the amount of deviation, in the same manner as with the tumor. Patient position correction, gate control of irradiation according to the amount of deviation, etc. are performed.

Note that the positional relationship RBT regarding the tumor position PT and the positional relationship RBR regarding the risk organ position PR may be positional relationships with respect to the same blood vessel (blood vessel position), or may be positional relationships with respect to mutually different blood vessels (blood vessel positions). There may be.

In addition, although the case where the positional relationship RBR regarding the risk organ position PR is further specified in addition to the positional relationship RBT regarding the tumor position PT has been described as an example, the present invention is not limited to this. The positional relationship may be identified with respect to either the positional relationship RBT regarding the tumor position PT or the positional relationship RBR regarding the risk organ position PR. That is, instead of the positional relationship RBT regarding the tumor position PT, the positional relationship RBR regarding the risk organ position PR may be specified.

According to these configurations, in addition to the effects obtained in the above-described embodiments, there is an effect that radiation irradiation to risk organs can be reduced.

In the above embodiment, it is assumed that the ultrasound image to be processed is one frame. However, in the planning stage and the treatment stage, the ultrasound diagnostic apparatus 3 may collect ultrasound images regarding a plurality of time-series frames, that is, may shoot a video. In this case, the processes shown in FIGS. 3 and 5 may be executed for each of the plurality of frames, or may be executed for any one frame among the plurality of frames. As this arbitrary frame, it is preferable to select a frame in a respiratory phase in which morphological changes over time are relatively small, for example, in a deep inhalation phase. Such a frame may be selected by the user via the input interface 65, or may be automatically selected based on the respiratory waveform collected by the respirometry device.

In the above-described embodiment, the case where the identification of the positional relationship, the estimation of the tumor position, the calculation of the amount of deviation, the patient position correction, and the gate control of the irradiation are executed by the treatment support device 6 is explained as an example. Not exclusively. These processes may be distributed by processing circuits included in the treatment planning CT device 2, the ultrasound diagnostic device 3, the treatment planning device 4, the radiation therapy device 5, and the treatment support device 6, or the treatment planning CT device 2. It may be executed by a processing circuit included in any one of the ultrasound diagnostic device 3, the treatment planning device 4, the radiotherapy device 5, and the treatment support device 6. In other words, the treatment planning device 4 or the radiation therapy device 5 may have a portion or elements equivalent to a portion of the treatment support device 6 according to the above-described embodiment. For example, the radiation therapy apparatus 5 may include the processing circuit 61, image processing circuit 62, and storage circuit 66 of the treatment support apparatus 6 according to the above-described embodiment. Here, the radiation therapy device 5 is an example of a medical processing device, and the processing circuit 61 that realizes the acquisition function 611 and the position estimation function 612 provided in the radiation therapy device 5 is an example of an acquisition unit and an estimation unit, respectively. The irradiation head of the radiation therapy apparatus 5 can be expressed as an example of an irradiation section. Further, for example, the treatment planning device 4 identifies the positional relationship between the blood vessel and the tumor, and the treatment support device 6 identifies the current tumor position using the positional relationship acquired from the treatment planning device 4. may be done.

In addition, although the above-mentioned embodiment demonstrated the case where the specification of the positional relationship was implemented in the planning stage as an example, it is not limited to this. Identification of positional relationships may be performed during the treatment phase. For example, when CT images for treatment planning are collected in the treatment stage, the positional relationship may be specified.

According to at least one embodiment described above, a tumor position can be estimated using an ultrasound image.

The word "processor" used in the above description means, for example, a circuit such as a CPU, GPU, Application Specific Integrated Circuit (ASIC), or Programmable Logic Device (PLD). PLDs include Simple Programmable Logic Devices (SPLDs), Complex Programmable Logic Devices (CPLDs), and Field Programmable Gate Arrays (FPGAs). A processor realizes its functions by reading and executing a program stored in a memory circuit. The storage circuit in which the program is stored is a computer-readable non-transitory storage medium. Note that instead of storing the program in the memory circuit, the program may be directly incorporated into the circuit of the processor. In this case, the processor realizes its functions by reading and executing a program built into the circuit. Further, instead of executing a program, functions corresponding to the program may be realized by a combination of logic circuits. Note that each processor of this embodiment is not limited to being configured as a single circuit for each processor, but may also be configured as a single processor by combining multiple independent circuits to realize its functions. good. Furthermore, a plurality of components in FIGS. 1 and 2 may be integrated into one processor to realize its functions.

Although several embodiments of the invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included within the scope and gist of the invention as well as within the scope of the invention described in the claims and its equivalents.

1...radiotherapy system,
2...CT device for treatment planning,
3... Ultrasonic diagnostic device,
4...Treatment planning device,
5...Radiation treatment device (irradiation section),
6...Treatment support device,
61...processing circuit,
62...Image processing circuit (generation unit),
63...communication interface,
64...Display device,
65...input interface,
66...Memory circuit,
611... Acquisition function (acquisition unit),
612...Position estimation function (estimation unit),
613...Difference amount calculation function (calculation unit),
614...Patient position correction function (correction section),
615...Gate control function (control unit),
616...Display control function (generation unit),
I10, I20, I40, I70, I80...Ultrasound image,
I11, I21, I41, I71, I81...B mode image (ultrasound image),
I12, I22, I42, I72, I82...Blood flow information image (ultrasound image),
I30...display image,
I50...parameter display image,
I60...Graph display image,
PB1...Vessel position,
RBT1...Positional relationship.

Claims (14)

an acquisition unit that acquires blood flow information based on ultrasound Doppler analysis regarding a region including a tumor in a treatment stage of radiotherapy;
The current tumor position is determined based on the current blood vessel position specified from the acquired blood flow information and the positional relationship between the blood vessel included in the region and the tumor at the planning stage of the radiotherapy. A medical processing device comprising: an estimator for estimating; The acquisition unit acquires blood flow information and tumor position regarding the region including the tumor in the planning stage,
The estimation unit specifies the positional relationship in the planning stage based on the blood vessel position specified from the blood flow information in the planning stage and the tumor position in the planning stage.
The medical processing device according to claim 1. The medical processing device according to claim 1 or 2, further comprising a calculation unit that calculates the amount of deviation between the estimated current tumor position and the tumor position at the planning stage. The medical processing apparatus according to claim 3, further comprising a correction unit that corrects the setup position of the target patient according to the calculated amount of deviation before the treatment in the treatment stage. The medical processing apparatus according to claim 3 or 4, further comprising a control unit that performs gate control of the radiation therapy according to the calculated amount of deviation during the treatment in the treatment stage. The medical processing device according to any one of claims 3 to 5, further comprising a generation unit that generates an image for displaying the calculated amount of deviation. The image includes the estimated current tumor position, the magnitude of the deviation amount, the direction of the deviation amount, the tumor position at the planning stage, the amount of user operation corresponding to the deviation amount, and a time series of the deviation amount. 7. The medical processing device of claim 6, comprising at least one of the following: The medical processing device according to any one of claims 1 to 7, wherein the estimator identifies a blood vessel position in a B-mode image regarding the region based on the acquired blood flow information. The estimating unit tentatively estimates the current tumor position from the B-mode image regarding the region, and corrects the tentatively estimated tumor position using the positional relationship at the planning stage, thereby estimating the current tumor position. The medical processing device according to any one of claims 1 to 8. The current blood vessel position identified from the acquired blood flow information includes a first blood vessel position and a second blood vessel position,
The estimation unit estimates the current tumor position based on the positional relationship of each blood vessel included in the region in the planning stage.
A medical processing device according to any one of claims 1 to 9. Any one of claims 1 to 10, wherein the estimation unit further estimates the current risk organ position based on the positional relationship between the blood vessel and the risk organ included in the region in the planning stage. The medical processing device according to item 1. The estimating unit identifies the positional relationship in the planning stage by aligning a CT image obtained by X-ray computed tomography regarding the region including the tumor and a B-mode image regarding the region in the planning stage. The medical processing device according to claim 2. The acquisition unit acquires a CT image by X-ray computed tomography regarding the region including the tumor in the planning stage,
The estimation unit specifies the tumor position based on the acquired CT image.
The medical processing device according to claim 1. an irradiation unit that irradiates a target patient with radiation according to a treatment plan for radiotherapy;
an acquisition unit that acquires blood flow information based on ultrasound Doppler analysis regarding a region including a tumor in the treatment stage of the radiation therapy;
The current tumor position is determined based on the current blood vessel position specified from the acquired blood flow information and the positional relationship between the blood vessel included in the region and the tumor at the planning stage of the radiotherapy. A radiation therapy apparatus comprising: an estimator for estimating;