WO2019159273A1

WO2019159273A1 - Radiation therapy device

Info

Publication number: WO2019159273A1
Application number: PCT/JP2018/005191
Authority: WO
Inventors: 優水城; 泰三本田
Original assignee: 株式会社日立製作所
Priority date: 2018-02-15
Filing date: 2018-02-15
Publication date: 2019-08-22

Abstract

This radiation therapy device is provided with: a radiation generating device (2) that generates radiation; a radiation irradiating device (3) that irradiates a patient with the radiation generated by the radiation generating device (2); and an in-therapy X-ray imaging device (4) that captures an X-ray image of the patient, wherein the in-therapy X-ray imaging device (4) extracts a neovascular plexus region around an affected part of the patient from the captured X-ray image, and the radiation irradiating device (3) irradiates the affected part with the radiation on the basis of the extracted neovascular plexus region.

Description

Radiation therapy equipment

This application relates to a radiotherapy apparatus for treating cancer and the like.

Cancer is one of the causes of death. Cancer treatment methods are roughly divided into three categories: surgical therapy, chemotherapy, and radiation therapy. Surgical treatment is a method of removing the tumor or its surroundings by surgery, and is a method that hopes for a complete cure. Chemotherapy is a method of tumor reduction or metastasis prevention by administration of an anticancer drug. Radiotherapy is a method of suppressing the growth of only tumor cells by irradiating the tumor with photons such as X-rays or γ-rays, particle beams such as protons or carbon rays, and utilizing the difference in the repair mechanism between normal cells and tumor cells. It is.

In radiotherapy, it is necessary to form an irradiation field in an appropriate position according to the shape or size of the tumor in order to suppress the irradiation of normal cells as much as possible. In order to form the irradiation field at an appropriate position, it is necessary to accurately grasp the position of the tumor. Therefore, some preparation is required before irradiation. First, an image of a region including a tumor is acquired by X-ray CT imaging, and a treatment plan is drawn up based on this image. On the day of irradiation, an operation called positioning is performed while comparing an X-ray image acquired in advance with an X-ray fluoroscopic image. Specifically, the position of the treatment table is set so that the reference position of the X-ray image acquired in advance and the X-ray fluoroscopic image acquired on the day of irradiation coincide with the bone that is considered to have little daily fluctuation in position, Adjust the angle. This work is indispensable to reproduce the posture at the time of treatment planning. When a tumor exists in a highly movable organ such as the liver or prostate, there is a method of using a pure gold marker placed in the vicinity of the tumor instead of bone at the reference position (see, for example, Patent Document 1).

Also, since the tumor formed in the thoracoabdominal region is accompanied by respiratory movement, it is necessary to accurately grasp the time variation of the tumor position. In this case as well, as with positioning, a method is used in which a pure gold marker is placed near the tumor and the position of the tumor is identified by tracking the movement of the marker.

In addition, in order to accurately irradiate the affected area with therapeutic radiation, image-guided radiation therapy (IGRT: Image Guided Radiation Therapy) is performed while irradiating therapeutic radiation while confirming the position of the affected area with an image such as an X-ray image. Has been proposed (for example, Patent Document 2). Patent Document 2 proposes a technique for identifying a lesioned part by performing X-ray imaging using a contrast agent having a property of being specifically accumulated in a lesioned part such as a tumor.

JP 2004-97646 A (paragraph 0146) JP 2013-252420 A

In conventional radiotherapy, a marker made of pure gold was placed in the vicinity of the tumor as a preliminary preparation for irradiation, so the marker might move or drop off depending on the placement site. In addition, for radiation, particularly particle beams, the marker blocks the irradiation field, so it has to be placed at a position away from the tumor. However, when the marker and the tumor are separated from each other, an error occurs when the position of the tumor is specified, and high-accuracy position specification cannot be realized. In addition, when placing the marker, local anesthesia for injection needle puncture to the placement site and insertion of the catheter is necessary, which causes a physical burden on the patient.

Further, in the technique proposed in Patent Document 2 for identifying a lesion part by X-ray imaging using a contrast agent having a property of being specifically accumulated in a lesion part such as a tumor, the metabolism of the lesion part is described. Differences in the degree of accumulation of contrast agent may occur due to functional variations, and differences in the density of X-ray images may occur. For this reason, there is a possibility that the entire lesion cannot be accurately grasped.

The present application discloses a technique for solving the above-described problem, and obtains a radiotherapy apparatus capable of specifying the position of a tumor with high accuracy without inserting or placing a marker in the body. With the goal.

A radiation therapy apparatus disclosed in the present application includes a radiation generation apparatus that generates radiation, a radiation irradiation apparatus that irradiates the patient with radiation generated by the radiation generation apparatus, and an X-ray treatment X image of the patient. In the radiotherapy apparatus comprising the X-ray imaging apparatus, the X-ray imaging apparatus during treatment extracts a neovascular network region from an image of a new blood vessel around a diseased part of a patient obtained from the acquired X-ray image, and performs radiation irradiation. The apparatus irradiates the affected area with radiation based on the extracted neovascular network region.

According to the radiotherapy apparatus disclosed in the present application, it is possible to obtain a radiotherapy apparatus that can specify the position of a tumor with high accuracy without inserting or placing a marker in the body.

1 is a block diagram showing a schematic configuration of a radiotherapy system including a radiotherapy apparatus according to Embodiment 1. FIG. 1 is a conceptual block diagram of a radiation therapy apparatus according to Embodiment 1. FIG. 3 is a flowchart for explaining the operation of the radiotherapy apparatus according to the first embodiment. 4A is a diagram showing an example of an X-ray image of a taken neovascular network, FIG. 4B is a diagram showing an example of an image subjected to median filter processing, FIG. 4C is a diagram showing an example of an image subjected to thinning filter processing, and FIG. FIG. 4 is a diagram illustrating an example of an image subjected to edge extraction filter processing. It is a notional block diagram of the radiotherapy apparatus by Embodiment 2. FIG. It is a top view which shows the structural example of the multileaf collimator of the radiotherapy apparatus by Embodiment 2. FIG. 10 is a flowchart for explaining the operation of the radiotherapy apparatus according to the second embodiment. 6 is a conceptual block diagram of a radiation therapy apparatus according to Embodiment 3. FIG. 10 is a flowchart for explaining the operation of the radiotherapy apparatus according to the third embodiment. It is a notional block diagram of the radiotherapy apparatus by Embodiment 4. FIG. 10 is a flowchart for explaining the operation of the radiotherapy apparatus according to the fourth embodiment. It is a block diagram which shows an example of a structure of a controller or a computing unit in each embodiment.

新生 Regarding tumors that are the subject of radiation therapy, new blood vessels are often observed in the vicinity of the tumor. This is due to the physiological function of forming a blood vessel as a supply path of oxygen and nutrients for the malignant tumor to grow. New blood vessels grow in close contact with each other so as to surround the surface of the tumor. In addition, it is known that when a contrast medium is injected into a blood vessel and X-ray imaging is performed, it becomes easier to distinguish from other tissues. In the blood vessels, since the contrast agent always flows without accumulating in the blood vessels, an image of the whole new blood vessels, that is, the new blood vessel network can be obtained by X-ray imaging. This application pays attention to this new blood vessel network, and by observing the new blood vessel network at the time of treatment, it determines the position of the affected part at the time of radiation treatment, the shape of the affected part, etc., and corresponds to the position of the affected part at the time of treatment or the shape of the affected part Thus, a technique for controlling the radiotherapy apparatus is disclosed.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a schematic configuration of a radiation therapy system including a radiation therapy apparatus 1 according to the first embodiment. The radiotherapy apparatus 1 includes a radiation generation apparatus 2, a radiation irradiation apparatus 3, and a treatment X-ray imaging apparatus 4. The radiation generation apparatus 2 includes a radiation generation source 21 that generates radiation such as X-rays, γ-rays, proton beams, carbon rays, and electron beams, and a radiation generation controller 22 that controls the radiation generation source 21. The radiation irradiating apparatus 3 includes a radiation irradiator 31 for irradiating the affected part of a patient who is a treatment target of radiation therapy with the radiation 5 generated by the radiation source 21 and an irradiation controller 32 for controlling the radiation irradiator 31. I have. The treatment X-ray imaging apparatus 4 has a function of performing X-ray imaging of a region including an affected part of a patient at the time of treatment, and extracting a region of a neovascular network around the affected part from a photographed image. The treatment planning apparatus 10 plans in advance how to irradiate the patient to be treated, and stores parameters of various devices in the radiation treatment apparatus as data for irradiating the patient with radiation according to the plan. In this case, the data is given to the radiotherapy apparatus 1. The radiation therapy apparatus 1 can perform radiation therapy according to the treatment plan by irradiating the patient with radiation based on the data given from the treatment planning apparatus 10.

FIG. 2 is a block diagram conceptually showing a configuration of a radiotherapy apparatus using a particle beam such as a carbon beam or a proton beam which is a bundle of charged particles as radiation. An accelerator for accelerating charged particles generates the particle beam 5 as the radiation generation source 21, and the particle beam 5 passes through the vacuum duct 51 and is transported to a radiation irradiator 31 provided downstream of the vacuum duct 51. Here, a bending electromagnet for changing the traveling direction of the particle beam 5 is provided at a portion where the vacuum duct 51 is bent, but is omitted in FIG. By the radiation irradiator 31, the particle beam 5a is irradiated to the affected part 6 of the patient who is the irradiation target placed on the treatment table. Various irradiation parameters for irradiation are set by the treatment planning apparatus 10. The parameters of the accelerator and radiation irradiator 31 as the radiation generation source 21 for irradiating with the irradiation parameters are transmitted from the system controller 20 to the radiation generation controller 22 and the irradiation controller 32 to generate radiation. The respective commands are output to the accelerator 21 and the radiation irradiator 31 as the source 21.

On the other hand, in order to acquire an X-ray image and confirm the position of the affected part 6 which is an irradiation target, an X-ray apparatus constituted by, for example,

X-ray tubes

41a and 41b and flat panel detectors (FPD) 42a and 42b 40 is installed. X-rays emitted from the X-ray tube 41a are detected by the FPD 42a, and X-rays emitted from the X-ray tube 41b are detected by the FPD 42b. X-ray images of the area including the affected area 6 are acquired by the

X-ray tubes

41a and 41b and the

FPDs

42a and 42b. The X-ray image processing calculator 43 processes the X-ray image acquired by the X-ray apparatus 40. In FIG. 1, the X-ray apparatus 40 and the X-ray image processing calculator 43 are collectively shown as a treatment X-ray imaging apparatus 4. The X-ray image processing calculator 43 may be configured to control the X-ray apparatus 40 and acquire an image. The entire treatment X-ray imaging apparatus 4 may be configured to acquire an X-ray image of an area including the affected part 6 and process the X-ray image. In FIG. 2, the X-ray apparatus 40 is configured to perform X-ray imaging from two directions. However, for example, when the therapeutic radiation is X-ray, the X-ray apparatus 40 may be configured to perform imaging only from one direction. Further, when it is necessary to grasp the position of the affected part 6 with higher accuracy, a configuration may be adopted in which X-ray imaging is performed from three directions.

Next, the operation of the radiation therapy apparatus 1 according to Embodiment 1 will be described with reference to the flowchart of FIG. The X-ray apparatus 40 continuously X-rays the neovascular network in the region including the affected part 6 to be tracked (for example, the frame rate is several tens of fps) (step ST1). At this time, it is desirable to inject the patient with a contrast agent for imaging blood vessels. The X-ray image processing calculator 43 filters the X-ray image data acquired by imaging using, for example, a so-called median filter (step ST2). The median filter performs processing for replacing the value of each pixel with the median value of surrounding pixels. This process is usually performed by executing software. FIG. 4A shows an example of an X-ray image obtained by imaging new blood vessels around the tumor. FIG. 4A is an image diagram of an X-ray image obtained by X-ray imaging of a region including a patient's tumor by injecting a contrast medium. An image obtained by imaging new blood vessels around a tumor is often obtained as an image having a difference in brightness in a region as a new blood vessel network. FIG. 4B shows an example of a processed image obtained by filtering the image data of FIG. 4A with a median filter of software. By performing the filtering process, it is possible to obtain an image in which the light and dark differences are averaged and the neovascular network region is extracted as an integral image. Before starting the treatment for irradiating radiation, the region of the neovascular network extracted using the filtered image is stored as a shape. During the treatment, the shape of the neovascular network extracted from X-ray images that are continuously captured is subjected to pattern matching with the shape of the neovascular network obtained before the start of treatment, so that the new blood vessel to be treated The position of the net is discriminated, and the position of the center of gravity of the neovascular network area is obtained (step ST3). The barycentric position can be obtained for the reference coordinates set in the X-ray apparatus 40. The coordinates set in the X-ray apparatus 40 are usually matched with the reference coordinates of the radiation irradiator 31.

In the filtering process (step ST2), the following process may be performed. The X-ray image processing calculator 43 thins the X-ray image data acquired by photographing. The thinning process is a process of converting an image into a line image with a narrow width, and is realized by, for example, a process of extracting a center line by repeating a step of narrowing the line width of an input image. This processing is usually performed by executing software. FIG. 4C shows an example of the image after the thinning filter processing is performed on the image of FIG. 4A by the thinning processing of software. The thinning process is equivalent to calculating the number density of blood vessels in the X-ray image. A region of the neovascular network is extracted from this image.

In the calculation of the centroid position of the neovascular network region (step ST3), the following processing may be performed. In the X-ray image subjected to the thinning process, one blood vessel is represented as one line regardless of the thickness of the blood vessel, so the density of the line in the X-ray image corresponds to the density of the blood vessel. Further, by performing the thinning process so that the line thickness of the X-ray image subjected to the thinning process is constant (for example, 1 pixel), the density of pixels having a brightness equal to or greater than the brightness threshold is determined in advance. A region that is equal to or higher than the density threshold can be determined as a region having a high number of blood vessels, that is, a region of a new blood vessel network, and a region of the new blood vessel network can be extracted. The center-of-gravity position of the region extracted as the neovascular network region is obtained.

If the X-ray image after the thinning process has two gradations, the brightness threshold is set to a higher value of the X-ray absorption amount of the two gradations. That is, for example, when 1 out of the pixel values 0 and 1 corresponds to a pixel value having a larger X-ray absorption amount, 1 is set as the brightness threshold. If the X-ray image after the thinning process is not two gradations, it is set so that the blood vessel can be detected by being input by a user interface or by calculation by a computer. The density threshold value is set so that a new blood vessel can be discriminated by being input from a user interface or calculated by a computer. When performing the process of converting the blood vessel of the X-ray image to the blood vessel density as described above, the region and position of the new blood vessel can be determined with higher accuracy.

In the above, after performing the thinning process, the region of the new blood vessel network is determined based on the blood vessel density. However, when an X-ray image with high definition of the new blood vessel is obtained, the thinning process is not performed. It is also possible to extract the neovascular network region by obtaining the blood vessel density from the acquired X-ray image itself.

In addition, depending on the tumor, the shape of the tumor can be obtained by extracting a region of the neovascular network from the processed image by performing a filtering process using an edge extraction filter for extracting an outline from the X-ray image in step ST2. May be identified. The filter processing by the edge extraction filter can be performed after the median filter processing, so that more appropriate shape extraction can be performed. FIG. 4D shows an image obtained by filtering the image of FIG. 4B using an edge extraction filter. The barycentric position of the neovascular network region can be obtained from the image subjected to the filter processing by the edge extraction filter.

When the calculation of the centroid position of the neovascular network region is completed, the X-ray image processing calculator 43 determines whether or not the centroid position is within the allowable region (step ST4). The allowable region is set by inputting from the user interface or calculating by a computer as a range in which the displacement of the center of gravity position is allowable with respect to the irradiation region set by the treatment plan. If the calculated position of the center of gravity of the neovascular network region is within the allowable region (YES in step ST4), an irradiation command signal is transmitted to the radiation generator 2 and the radiation irradiation device 3 to irradiate the radiation (step ST5). If it is not within the allowable region (NO in step ST4), an irradiation stop signal is transmitted, and the process returns to step ST1 without irradiation. Since the X-ray image is acquired in real time, the irradiation can be stopped in real time when the position of the affected part 6 to be irradiated is shifted due to the patient's breathing or the like. While the irradiation dose does not reach the planned dose (NO in step ST6), this series of operations is continued. When the irradiation dose reaches the planned dose (step ST6 YES), the irradiation is terminated.

In addition, although the example of the radiotherapy apparatus which uses a particle beam as a therapeutic radiation was illustrated in FIG. 2, as a therapeutic radiation, other radiations, such as not only a particle beam but X-rays, may be sufficient. .
The center of gravity is used as the position of the representative point that represents the position of the neovascular network area. However, what is used as the representative point is not limited to the center of gravity, and any point can be determined as the position of the neovascular network area. It may be a point. The same applies to the subsequent embodiments with respect to the position of the representative point representing the position of the neovascular network region.

As described above, in the radiotherapy apparatus according to the first embodiment, when treating by irradiating with radiation, a region of the neovascular network around the affected area of the patient is extracted from the photographed X-ray image, and the extracted neovascularization The radiation irradiation device irradiates the affected area with radiation based on the area of the net. More specifically, the position of the representative point such as the center of gravity position is obtained from the area of the neovascular network extracted by the filtered image of the X-ray image of the area including the tumor that is the affected area, and the position of the representative point is the allowable area. In this case, therapeutic radiation was applied, and when it was not within the allowable range, radiation was not applied. In the radiotherapy apparatus according to Embodiment 1, the position of the affected part is obtained using an X-ray image obtained by X-ray imaging of the structure of the new blood vessel network that does not depend on the metabolic function. The position of the affected part can be determined with higher accuracy than the method of determining the affected part from the image of the contrast agent that is accumulated depending on the metabolic function of the affected part. Moreover, the position of the affected part can be determined with high accuracy without using a marker.

Embodiment 2. FIG.
FIG. 5 is a block diagram conceptually showing the structure of the radiation therapy apparatus according to the second embodiment. In the radiotherapy apparatus according to the second embodiment, the radiation irradiator 31 is provided with a multi-leaf collimator 32 for setting the two-dimensional shape of the irradiation region by limiting the irradiation region of the radiation. An example of the configuration of the multi-leaf collimator 32 is shown in FIG. 6 as a plan view seen from the direction of the radiation irradiation axis. The multi-leaf collimator 32 is configured to set the shape of the region through which radiation passes, that is, the opening 323 by driving a large number of collimator leaves 321 left and right in the example of FIG. Yes.

Next, the operation of the radiation therapy apparatus 1 according to the second embodiment will be described with reference to the flowchart of FIG. The X-ray apparatus 40 continuously X-rays the neovascular network in the region including the affected part 6 to be tracked (for example, the frame rate is several tens of fps) (step ST1). At this time, it is desirable to inject the patient with a contrast agent for imaging blood vessels. In the X-ray image processing calculator 43, the X-ray image data acquired by imaging is filtered by the median filter described in the first embodiment, for example (step ST2). Further, the thinning process described in Embodiment 1 may be performed. Using the neovascular network region extracted from the processed image, the center-of-gravity position of the neovascular network region is obtained (step ST3).

When the calculation of the center-of-gravity position coordinates of the neovascular network region is completed, the X-ray image processing calculator 43 determines whether or not the center-of-gravity position coordinates are within the allowable region (step ST4). The allowable region is set by inputting from the user interface or calculating by a computer as a range in which the displacement of the center of gravity position is allowable with respect to the irradiation region set by the treatment plan. If the calculated centroid position of the neovascular network area is within the allowable area (step ST4 YES), the position of the opening 323 of the multi-leaf collimator 32 is moved corresponding to the deviation of the centroid position coordinate from the treatment plan. Thus, the setting condition of the multi-leaf collimator 32 is corrected with respect to the condition set by the treatment planning apparatus (step ST41), and radiation irradiation is performed (step ST5). If it is not within the allowable region (NO in step ST4), an irradiation stop signal is transmitted, and the process returns to step ST1 without irradiation. Since the X-ray image is acquired in real time, when the position of the affected part 6 that is the irradiation target is shifted due to the patient's breathing or the like, or when there is a slight shift, the irradiation is performed by correcting the setting conditions of the multi-leaf collimator 32. Try to shift the position. If it deviates significantly, the irradiation is stopped. While the irradiation dose does not reach the planned dose (NO in step ST6), this series of operations is continued. When the irradiation dose reaches the planned dose (step ST6 YES), the irradiation is terminated.

Furthermore, depending on the tumor, the shape of the tumor can be obtained by extracting a region of the new blood vessel network from the processed image by performing filter processing using an edge extraction filter for extracting an outline from the X-ray image in step ST2. Alternatively, it may be possible to specify the shape of the irradiation region by adding a margin to the tumor region. The filter processing by the edge extraction filter can be performed after the median filter processing so that a more appropriate shape can be extracted. In this case, in step ST41, the setting condition of the multi-leaf collimator 32 is corrected based on the position and shape of the neovascular network region, and the opening shape is corrected, so that not only the position of the opening 323 but also the irradiation region. The shape itself can also be corrected. The shape of the neovascular network region may be obtained from an image obtained by median filter processing, or may be obtained from the neovascular network region extracted by thinning processing. Also in these processes, as in the edge extraction filter process, the setting conditions of the multi-leaf collimator 32 are corrected based on the position and shape of the neovascular network region, and the opening shape is corrected, so that only the position of the opening 323 is obtained. Instead, the shape of the irradiation area itself can be corrected.

In addition, in FIG. 5, the example of the radiotherapy apparatus which uses a particle beam as a radiation was shown and demonstrated, However, The radiation is not limited to a particle beam, but may be other radiation such as an X-ray.

As described above, in the radiotherapy apparatus according to the second embodiment, when treating by irradiating with radiation, a region of the neovascular network around the affected area of the patient is extracted from the captured X-ray image, and the extracted neovascularization The radiation irradiation device irradiates the affected area with radiation based on the area of the net. More specifically, the position of the representative point such as the center of gravity of the affected area is obtained from the area of the neovascular network extracted by an image obtained by filtering the X-ray image of the area including the tumor which is the affected area, or the position of the representative point When the shape of the region of the neovascular network is obtained and the position of the representative point is in the allowable region, the setting condition of the multi-leaf collimator 32 is corrected and the therapeutic radiation is irradiated, and the position of the representative point is within the allowable range. If not, radiation was not applied. In the radiotherapy apparatus according to the second embodiment, the position of the representative point of the affected area or the shape of the irradiation region is obtained using an X-ray image obtained by X-ray imaging of the structure of the neovascular network that does not depend on the metabolic function. Therefore, the position or shape of the affected part can be determined with higher accuracy than the method of determining the affected part from the contrast agent images accumulated depending on the metabolic function of the affected part described in Patent Document 2. be able to. Moreover, the position of the affected part can be determined with high accuracy without using a marker.

Embodiment 3 FIG.
FIG. 8 is a block diagram conceptually showing the structure of the radiation therapy apparatus according to the third embodiment. In the radiotherapy apparatus according to the third embodiment, the radiation irradiator 31 includes a scanning electromagnet 33 that uses a particle beam as radiation and deflects the particle beam in a two-dimensional direction perpendicular to the traveling direction of the particle beam. The operation of the scanning electromagnet 33 is set by a signal from the irradiation controller 32. The scanning electromagnet 33 scans so that the excitation current is set so as to sequentially change the deflection angle of the particle beam 5b, and as a result, the particle beam 5b irradiates the irradiation region set by the treatment plan.

Next, the operation of the radiation therapy apparatus 1 according to the third embodiment will be described with reference to the flowchart of FIG. The X-ray apparatus 40 continuously X-rays the neovascular network in the region including the affected part 6 to be tracked (for example, the frame rate is several tens of fps) (step ST1). At this time, it is desirable to inject the patient with a contrast agent for imaging blood vessels. In the X-ray image processing calculator 43, the X-ray image data acquired by imaging is filtered by the median filter described in the first embodiment, for example (step ST2). Further, the thinning process described in Embodiment 1 may be performed. Alternatively, the processing by the edge extraction filter described in Embodiments 1 and 2 may be performed. Using the neovascular network region extracted from the processed image, the center-of-gravity position of the neovascular network region is obtained (step ST3).

When the calculation of the centroid position of the neovascular network region is completed, the X-ray image processing calculator 43 determines whether or not the centroid position is within the allowable region (step ST4). The allowable region is set by inputting from the user interface or calculating by a computer as a range in which the displacement of the center of gravity position is allowable with respect to the irradiation region set by the treatment plan. If it is within the allowable region (YES in step ST4), the excitation current value of the scanning electromagnet 33 is corrected with respect to a preset set value corresponding to the displacement of the center of gravity position from the treatment plan (step ST42). ), Radiation irradiation is performed (step ST5). If it is not within the allowable region (NO in step ST4), an irradiation stop signal is transmitted, and the process returns to step ST1 without irradiation. Since the X-ray image is acquired in real time, when the position of the affected part 6 that is the irradiation target is shifted due to the patient's breathing or the like, the setting value of the excitation current value of the scanning electromagnet 33 is corrected in the case of a slight shift. Therefore, the irradiation position is shifted. If there is a large deviation, stop irradiation.

As described above, in the radiotherapy apparatus according to the third embodiment, when irradiating with a particle beam as radiation, the region of the neovascular network around the affected area of the patient is extracted from the photographed X-ray image, Based on the extracted neovascular network region, the radiation irradiation device irradiates the affected area with radiation. More specifically, the position of a representative point such as the position of the center of gravity of the affected area is obtained from the area of the neovascular network extracted by an image obtained by filtering the X-ray image of the area including the tumor that is the affected area. When the position of the representative point is in the allowable region, the setting condition of the scanning electromagnet 33 that deflects the particle beam in accordance with the displacement of the representative point is corrected to irradiate therapeutic radiation, and the position of the representative point is allowable When it was not in range, radiation was not irradiated. In the radiotherapy apparatus according to Embodiment 3, the center of gravity position of the affected area is obtained using an X-ray image obtained by X-ray imaging of the structure of the neovascular network that does not depend on the metabolic function. Compared to the method of determining a lesion from a contrast agent image accumulated depending on the metabolic function of the lesion described in the above, the position of the lesion can be determined with higher accuracy. Moreover, the position of the affected part can be determined with high accuracy without using a marker.

Embodiment 4 FIG.
FIG. 10 is a block diagram conceptually showing the structure of the radiation therapy apparatus according to the fourth embodiment. In the radiotherapy apparatus, a patient is placed on a treatment table 60 and irradiated with radiation. In order to irradiate the affected part 6 with radiation, it is necessary to move and position the patient. For this reason, the treatment table 60 is provided with a mechanism for moving the treatment top plate 61 on which the patient is fixed. In the radiotherapy apparatus of the fourth embodiment, the positioning calculator 62 obtains the amount of movement of the treatment top plate 61 for positioning based on the X-ray image of the new blood vessel network imaged by the X-ray apparatus 40, The treatment top 61 is moved to position the patient. Here, the treatment table 60, the treatment top plate 61, and the positioning calculator 62, which are members necessary for positioning, are referred to as the positioning mechanism 6.

Next, the operation of the radiation therapy apparatus according to the fourth embodiment will be described with reference to the flowchart of FIG. The X-ray apparatus 40 performs X-ray imaging of a neovascular network in a region including the affected part 6 to be tracked (step ST1). At this time, it is desirable to inject the patient with a contrast agent for imaging blood vessels. In the X-ray image processing calculator 43, the X-ray image data acquired by imaging is filtered by the median filter described in the first embodiment, for example (step ST2). Further, the thinning process described in Embodiment 1 may be performed. Alternatively, the processing by the edge extraction filter described in Embodiments 1 and 2 may be performed. Using the neovascular network region extracted from the processed image, the center-of-gravity position of the neovascular network region is obtained (step ST3).

Next, an amount of movement of the treatment top plate 61 so that the center of gravity position becomes a predetermined position is calculated (step ST43). The amount of movement (step ST43) is not calculated from the position of the center of gravity, but an image of the neovascular network obtained by filtering in step ST2 and X obtained by filtering by X-ray imaging during treatment planning. It can also be calculated by collating with a line image. The collation can be performed by subtracting both images, calculating a movement amount on the image that minimizes the difference information, and converting the movement amount on the image into a movement amount of the treatment table 61. Next, the treatment top 61 is driven and controlled so as to correct the position of the treatment top 61 according to the calculated movement amount (step ST44).

In addition, in FIG. 10, the example of the radiotherapy apparatus which uses a particle beam as a therapeutic radiation was demonstrated and demonstrated, However, as a therapeutic radiation, other radiations, such as an X-ray, are not restricted to a particle beam. I do not care.

As described above, in the radiotherapy apparatus according to the fourth embodiment, when a treatment is performed by irradiating a particle beam as radiation, an X-ray image of a region including a tumor which is an affected part is filtered and is newly born. The region of the blood vessel network is extracted, the position of the representative point such as the priority position of the region of the new blood vessel network is obtained, and the patient is positioned based on the obtained position of the representative point. Alternatively, an image of a neovascular network extracted by filtering an X-ray image of a region including a tumor which is an affected part, and an X-ray image of a region including a tumor obtained by X-ray imaging at the time of treatment planning are filtered. The patient was positioned by collating with the extracted neovascular network image. In the radiotherapy apparatus according to the fourth embodiment, the amount of movement of the treatment top 61 for positioning is obtained using an X-ray image obtained by X-ray imaging of the structure of the neovascular network that does not depend on the metabolic function. Therefore, compared to the method described in Patent Document 2 for determining a lesion from an image of a contrast agent accumulated depending on the metabolic function of the lesion, positioning can be performed with high accuracy. Further, it is possible to perform positioning accurately without using a marker.

As described above, in each embodiment, the radiation generation controller 22, the irradiation controller 32, the X-ray image processing calculator 43, and the positioning calculator 62 each have a hardware configuration as shown in FIG. For example, it is realized as a computer including a processor 11 such as a CPU, a memory 12, and an input / output interface 13 for exchanging data and signals with other devices, and includes a display 14 for displaying information as necessary. Each process is realized by a processor 11 that executes a program stored in the memory 12. For example, the processing performed by each of the above controllers or arithmetic units is realized by the processor 11 executing the programs stored in the memory 12. Further, one processor 11 may serve as, for example, the radiation generation controller 22 and the irradiation controller 32, or may serve as the irradiation controller 32 and the X-ray image processing arithmetic unit 43. The generation controller 22, the irradiation controller 32, the X-ray image processing calculator 43, etc. may all be realized by a single processor.

It should be noted that the embodiments can be combined, or the embodiments can be appropriately modified or omitted.

1. Radiation therapy device, 2. Radiation generation device, 3. Radiation irradiation device, 4. Treatment X-ray imaging device, 5. Radiation, 6. Positioning mechanism, 32. Multi-leaf collimator, 33. Scanning electromagnet

Claims

Radiation therapy comprising a radiation generation device that generates radiation, a radiation irradiation device that irradiates a patient with radiation generated by the radiation generation device, and a treatment X-ray imaging device that captures an X-ray image of the patient In the device
The X-ray imaging apparatus for treatment extracts a region of a new blood vessel network from an image of a new blood vessel around the affected area of the patient obtained from the photographed X-ray image, and the radiation irradiation device extracts the neovascular network of the extracted new blood vessel network. A radiotherapy apparatus that irradiates the affected area with the radiation based on a region.
2. The radiation according to claim 1, wherein the X-ray imaging apparatus for treatment extracts a region of the new blood vessel network by obtaining a blood vessel density from an image of a new blood vessel around the affected area of the patient. Therapeutic device.
3. The radiotherapy apparatus according to claim 2, wherein the X-ray radiographing apparatus at the time of treatment performs thinning processing from an image of new blood vessels around the affected area of the patient to obtain the density of the blood vessels.
The radiotherapy apparatus according to claim 1, wherein the X-ray radiographing apparatus at the time of treatment extracts a region of the neovascular network from the neovascular image around the affected area of the patient by filtering.
The radiotherapy apparatus according to claim 4, wherein the filtering process is a filtering process using a median filter.
The radiotherapy apparatus according to claim 4, wherein the filtering process is a filtering process using an edge extraction filter.
The treatment X-ray imaging apparatus obtains a position of a representative point of the extracted neovascular network region,
The radiation irradiating device irradiates the patient with radiation when the obtained position of the representative point is in a preset allowable region, and the patient when the obtained position of the representative point is not in the preset allowable region. The radiotherapy apparatus according to claim 1, wherein the radiation therapy apparatus is controlled not to irradiate the radiation.
The treatment X-ray imaging apparatus obtains a position of a representative point of the extracted neovascular network region,
The radiation irradiation apparatus includes a multi-leaf collimator for limiting an irradiation area, and when the obtained position of the representative point is in a preset allowable area, the position of the obtained representative point and a preset representative point The patient is irradiated with radiation by correcting the aperture shape of the multi-leaf collimator based on the deviation from the position, and the patient is not irradiated with radiation when the obtained representative point position is not in the preset allowable region. The radiotherapy apparatus according to claim 1, wherein the radiotherapy apparatus is controlled.
The X-ray apparatus for treatment determines the position and shape of the representative point of the extracted neovascular network region,
The radiation irradiating apparatus includes a multi-leaf collimator for limiting an irradiation area, and when the obtained representative point position is in a preset allowable area, the position and shape of the representative point in the neovascular network area Correcting the aperture shape of the multi-leaf collimator based on the above, and irradiating the patient with radiation, and controlling the patient not to irradiate with radiation when the obtained representative point position is not in a preset allowable region The radiotherapy apparatus according to any one of claims 1 to 6.
The radiation is a particle beam, and the radiation irradiation device includes a scanning electromagnet that deflects and scans the particle beam,
When the obtained representative point position is in a preset allowable region, the excitation current value of the scanning electromagnet is corrected based on the deviation between the obtained representative point position and the preset representative point position. The patient is irradiated with radiation, and control is performed so as not to irradiate the patient when the position of the obtained representative point is not within a preset allowable region. A radiotherapy device according to 1.
A radiation generating apparatus that generates radiation, an X-ray imaging apparatus for treatment that captures an X-ray image of a patient, a radiation irradiation apparatus that irradiates the patient with radiation generated by the radiation generating apparatus, and positioning of the patient In a radiotherapy apparatus provided with a positioning mechanism for performing,
The therapeutic X-ray imaging apparatus extracts a neovascular network region from an image of a new blood vessel around the affected area of the patient obtained from the captured X-ray image, and the positioning mechanism applies the extracted neovascular network region to the extracted neovascular network region. A radiotherapy apparatus characterized by positioning a patient on the basis thereof.
The radiotherapy according to claim 11, wherein the X-ray imaging apparatus for treatment extracts a region of the new blood vessel network by obtaining a blood vessel density from an image of a new blood vessel around the affected area of the patient. apparatus.
The radiotherapy apparatus according to claim 12, wherein the X-ray imaging apparatus during treatment obtains the density of the blood vessels by performing a thinning process from an image of new blood vessels around the affected area of the patient.
The radiotherapy apparatus according to claim 11, wherein the X-ray imaging apparatus for treatment extracts a region of the neovascular network from the neovascular image around the affected area of the patient by filtering.
The radiotherapy apparatus according to claim 14, wherein the filtering process is a filtering process using a median filter.
The radiotherapy apparatus according to claim 14, wherein the filtering process is a filtering process using an edge extraction filter.
The treatment X-ray imaging apparatus obtains a position of a representative point of the extracted neovascular network region,
The radiotherapy according to any one of claims 11 to 16, wherein the positioning mechanism performs positioning based on a difference between the obtained position of the representative point and a preset position of the representative point. apparatus.
The positioning mechanism includes a neovascular network image obtained by filtering the photographed X-ray image and a neovascular network image obtained by filtering an X-ray image photographed in advance during treatment planning. The radiotherapy apparatus according to claim 11, wherein positioning is performed by collation.