JP2008154861A - Radiation therapy system - Google Patents

Abstract

[PROBLEMS] To accurately irradiate a therapeutic radiation beam to a treatment target part that periodically reciprocates even though the position of the treatment target part such as a tumor periodically changes due to breathing of a human body. Provided is a radiation therapy system capable of
The radiation therapy system includes in-vivo imaging devices (13, 17) and a therapeutic radiation beam irradiation device (7). When the treatment target part 3 such as a tumor in the human body 1 is treated, a fluoroscopic image 25 inside the human body 1 is generated over time by the human body imaging devices 13 and 17. When the image information of the fluoroscopic image 25 generated with the passage of time substantially coincides with the image information of the reference fluoroscopic image generated in advance in a specific respiratory phase, the therapeutic radiation beam irradiation apparatus 7 performs treatment in the human body 1. The target portion 3 is irradiated with a therapeutic radiation beam 9.
[Selection] Figure 3

Description

  The present invention relates to a radiotherapy system that treats a treatment target portion by irradiating the treatment target portion in a human body, and more particularly to a treatment target portion that periodically reciprocates by breathing of the human body. The present invention also relates to a radiotherapy system capable of accurately irradiating a therapeutic radiation beam.

  2. Description of the Related Art Various types of radiation treatment systems for treating a treatment target portion in a human body, specifically, for example, a treatment of a tumor by irradiating the tumor with a radiation beam have been known (for example, (See Patent Document 1). The position of such a tumor often varies periodically as the human body breathes. For example, regarding a lung tumor, the fluctuation range of the position accompanying the breathing of the human body may exceed 2 to 3 cm. For this reason, when a treatment is performed by irradiating a tumor with a radiation beam, it is necessary to take into account the variation of the tumor position accompanying the respiration of the human body.

JP 2006-51064 A

  In order to deal with the above-mentioned problems related to the periodic fluctuation of the position of the tumor caused by breathing of the human body, the breathing of the human body is temporarily stopped and the radiation beam is irradiated on the tumor during that time, or the human body accompanying breathing It is known to perform a respiration synchronized irradiation method in which a change in the skin surface is detected and the irradiation position of the radiation beam is changed in accordance with the change in the skin surface. Here, as a respiratory phase detection means necessary for the above-mentioned respiratory synchronous irradiation method, conventionally, a strain gauge is attached to the skin surface of the human body, and the fluctuation of the human skin surface due to breathing is used as a pressure change by the strain gauge. Those that detect and detect the respiratory phase from this pressure change have been adopted.

  However, in the method of temporarily stopping breathing of the human body and irradiating the tumor with the radiation beam during that time, the tumor position may not be stably stopped due to individual differences among patients. In addition, when a strain gauge is used in the breathing synchronized irradiation method, the pressure detection characteristic corresponding to the position fluctuation of the skin surface changes depending on the state of the strain gauge attached to the skin surface of the human body. There was a problem that it was difficult to detect the phase.

  The present invention has been made in consideration of such points, and the treatment that reciprocates periodically even though the position of the treatment target portion such as a tumor periodically changes due to the respiration of the human body. It is an object of the present invention to provide a radiotherapy system capable of accurately irradiating a target portion with a therapeutic radiation beam.

  A first aspect of the present invention is a radiotherapy system that treats a treatment target portion by irradiating the treatment target portion such as a tumor in a human body with the radiation beam for imaging. A human body imaging device that generates a fluoroscopic image inside the human body by irradiation, a therapeutic radiation beam irradiation device that irradiates the human body with a therapeutic radiation beam, the human body imaging device, and the therapeutic radiation beam irradiation device A fluoroscopic image of the inside of the human body is generated over time by the human body imaging device, and image information of the fluoroscopic image generated over time is generated in a specific respiratory phase generated in advance. When the image information of the reference fluoroscopic image in FIG. Is substantially the same, the therapeutic radiation beam is irradiated to the treatment target portion in the human body by the therapeutic radiation beam irradiation device. A control device for controlling such a radiation treatment system, comprising the.

  According to the above-described radiotherapy system, the therapeutic radiation beam is irradiated to the treatment target portion only in a specific respiratory phase, even though the position of the treatment target portion such as a tumor periodically changes due to breathing of the human body. Therefore, the position of the treatment target portion at the time of irradiation of the treatment radiation beam becomes substantially the same, and the treatment radiation beam can be accurately irradiated to the treatment target portion that periodically reciprocates.

  In such a radiotherapy system, it is preferable that the specific respiratory phase of the reference fluoroscopic image generated in advance in the control device is a peak time of the expiration period or the inhalation period. Here, when the specific respiratory phase is set to the peak of the expiration period or the inhalation period, the treatment target part is temporarily stopped at the peak of the expiration period or the inhalation period. Radiation beam irradiation can be performed with higher accuracy.

  In such a radiation therapy system, the human body imaging device generates a fluoroscopic image that includes each of the treatment target part and a body reference part that is larger than the treatment target part and interlocks with the respiration of the human body. The control device applies a therapeutic radiation beam irradiation device to a treatment target portion in the human body when the in-vivo reference portion in the fluoroscopic image generated with time substantially matches the in-vivo reference portion in the reference fluoroscopic image. It is preferable that control is performed so as to irradiate the therapeutic radiation beam. It is more preferable that the in-vivo reference portion is a diaphragm in the human body. As described above, generally, an in-vivo reference portion such as a diaphragm is larger than a treatment target portion such as a tumor. Therefore, the in-vivo reference portion is more clearly depicted in the fluoroscopic image than the treatment target portion. Therefore, by using the position of the in-vivo reference portion as image information rather than using the position of the treatment target portion itself as image information in the fluoroscopic image, the image information of the fluoroscopic image generated over time and the specific information Comparison with the image information of the reference fluoroscopic image in the respiratory phase can be performed.

  In such a radiotherapy system, the control device is preliminarily input with a first CT image inside the human body in a specific respiratory phase before treatment of the human body, and the human body imaging device captures an imaging radiation beam for the human body. A plurality of fluoroscopic images inside the human body are generated while changing the irradiation direction, and a plurality of second CT images in various respiratory phases are generated based on the plurality of fluoroscopic images, and the second CT images are generated from the plurality of second CT images. It is preferable that one second CT image that is most approximate to the 1CT image is selected, and the fluoroscopic image related to the respiratory phase corresponding to the one second CT image is set as the reference fluoroscopic image. Here, when performing the setting of the reference fluoroscopic image, it is more preferable that the second CT image is generated from a plurality of fluoroscopic images at the same respiratory phase by the projection reconstruction method. Further, a mounting table for mounting a human body is further provided, and the position of the mounting table is set at a predetermined position by the control device in advance. When performing the setting of the image, the position of the mounting table is determined based on the amount of positional deviation between one second CT image that most closely approximates the first CT image and the first CT image among a plurality of second CT images. It is preferable to set in advance.

  According to a second aspect of the present invention, there is provided a radiation therapy system for treating a treatment target portion by irradiating the treatment target portion such as a tumor in a human body with the radiation beam for imaging. An in-vivo imaging device that generates a fluoroscopic image of the inside of the human body by irradiation and a therapeutic radiation beam irradiation device that irradiates the human body with a therapeutic radiation beam, the irradiation position of the therapeutic radiation beam being varied A therapeutic radiation beam irradiating device, and a control device for controlling the human body imaging device and the therapeutic radiation beam irradiating device. Based on the image information of the fluoroscopic image generated over time and the image information of the reference fluoroscopic image in each respiratory phase generated in advance. And a control device that performs control to vary the irradiation position with time so that the irradiation position of the therapeutic radiation beam irradiated from the irradiation beam irradiation apparatus follows the treatment target portion in the human body. This is a featured radiotherapy system.

  According to the above-described radiotherapy system, the position of the treatment target portion such as a tumor is periodically changed by breathing of the human body, but the treatment radiation beam is irradiated in response to the change in the position of the treatment target portion. Since the therapeutic radiation beam always hits the treatment target portion by changing the position, the treatment radiation beam can be accurately irradiated to the treatment target portion that periodically reciprocates. Become.

  In such a radiation therapy system, it is preferable that the therapeutic radiation beam irradiation apparatus has a collimator, and the collimator changes the irradiation position of the therapeutic radiation beam. In particular, the collimator is preferably a multi-leaf collimator.

  In such a radiotherapy system, the control device receives in advance a plurality of first CT images inside the human body in various respiratory phases before treatment of the human body, and is used for imaging the human body by the human body imaging device. A plurality of fluoroscopic images inside the human body are generated while changing the irradiation direction of the radiation beam, and a plurality of second CT images in various respiratory phases are generated based on the plurality of fluoroscopic images, and the plurality of second CT images and The plurality of first CT images are compared with each other to associate a fluoroscopic image related to the second CT image that is closest to each first CT image as a reference fluoroscopic image, and the therapeutic radiation beam is applied to the human body by the therapeutic radiation beam irradiation device. When irradiating, image information related to a fluoroscopic image inside the human body obtained by the human body imaging device, and the plurality of first CTs The image information of each reference fluoroscopic image associated with each image is compared, and the irradiation position of the therapeutic radiation beam irradiated from the therapeutic radiation beam irradiation apparatus is determined based on the first CT image related to the closest image information. It is preferable to perform control that varies over time. Further, a mounting table for mounting a human body is further provided, and the position of the mounting table is set in a predetermined position by the control device in advance. Before irradiating the human body with the therapeutic radiation beam by the radiation beam irradiation apparatus for medical use, the first CT image that is closest to one second CT image among the plurality of second CT images obtained by the human body imaging apparatus and the one More preferably, the position of the mounting table is set in advance based on the amount of positional deviation from the second CT image.

  According to a third aspect of the present invention, there is provided a radiotherapy system for treating a treatment target portion by irradiating the treatment target portion such as a tumor in a human body with a radiation beam for mounting the human body. A mounting table such as a bed, a human body imaging device that generates a fluoroscopic image inside the human body by irradiating the human body mounted on the mounting table with an imaging radiation beam, and a human body mounted on the mounting table. A therapeutic radiation beam irradiation apparatus that irradiates a therapeutic radiation beam, and a control device that controls the mounting table, the human body imaging apparatus, and the therapeutic radiation beam irradiation apparatus, wherein the human body imaging apparatus is used to control the inside of the human body. The fluoroscopic image is generated over time, and based on the image information of the fluoroscopic image generated over time and the image information of the reference fluoroscopic image in each respiratory phase generated in advance before the treatment of the human body. And a control device that performs control to move the mounting table over time so that the therapeutic radiation beam irradiated from the therapeutic radiation beam irradiation device always irradiates the treatment target portion in the human body. A radiation therapy system characterized by

  According to the above-described radiotherapy system, although the position of the treatment target portion such as a tumor periodically changes due to the breathing of the human body, the bed such as a bed is set in response to the change in the position of the treatment target portion. Since the therapeutic radiation beam always strikes the treatment target portion by moving, the therapeutic radiation beam can be accurately irradiated to the treatment target portion that periodically reciprocates.

  In such a radiotherapy system, the control device is preliminarily input with a plurality of first CT images inside the human body in various respiratory phases and the coordinates of the treatment target portion corresponding to each first CT image before the human body is treated. And generating a plurality of fluoroscopic images inside the human body while changing the irradiation direction of the imaging radiation beam on the human body by the human body imaging device, and a plurality of second CTs in various respiratory phases based on the plurality of fluoroscopic images. Generating an image, comparing the plurality of second CT images with the plurality of first CT images, and associating a fluoroscopic image related to the second CT image that is most approximate for each first CT image to be a reference fluoroscopic image; Of the human body obtained by the human body imaging device when the therapeutic radiation beam is irradiated to the human body by the radiation beam irradiation device for medical use. The image information related to the fluoroscopic image and the image information of each reference fluoroscopic image related to each of the plurality of first CT images, and the coordinates of the treatment target part corresponding to the first CT image related to the most approximate image information Based on the above, it is preferable that the mounting table is changed over time. In addition, the control device most closely approximates one second CT image among a plurality of second CT images obtained by the human body imaging device before irradiating the human body with the therapeutic radiation beam by the therapeutic radiation beam irradiation device. It is particularly preferable that the initial position of the mounting table is set based on the amount of positional deviation between the first CT image and the second CT image.

  According to the radiotherapy system of the present invention, although the position of a treatment target portion such as a tumor periodically changes due to the breathing of the human body, the therapeutic radiation is applied to the treatment target portion that periodically reciprocates. The beam can be irradiated with high accuracy.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 to 6 are views showing an embodiment of a radiation therapy system according to the present invention.
Among these, FIG. 1 is a schematic perspective view showing a configuration of a radiotherapy system in one embodiment of the present invention, FIG. 2 is a schematic configuration diagram of the radiotherapy system shown in FIG. 1, and FIG. FIG. 3 is a block diagram showing control contents in the control device of the radiotherapy system shown in FIGS. 1 and 2. 4 is a fluoroscopic image inside the human body obtained by the human body imaging device of the radiotherapy system shown in FIGS. 1 and 2, and FIG. 5 shows the positional variation of the diaphragm in the fluoroscopic image shown in FIG. FIG. 6 is a diagram showing a respiratory phase obtained from the positional variation of the diaphragm shown in FIG.

  The radiation treatment system according to the present embodiment performs treatment of a tumor 3 by irradiating a treatment target portion inside the human body 1, specifically, a tumor 3 such as a lung tumor with a radiation beam. is there. As shown in FIG. 1 and FIG. 2, especially FIG. 2, the radiation therapy system includes an imaging radiation beam irradiator 13 that irradiates a human body 1 with an imaging radiation beam 15, and a human body irradiated with the imaging radiation beam irradiator 13. An imaging radiation beam detector 17 that receives the imaging radiation beam 15 that has passed through and generates a fluoroscopic image 25 (see FIG. 4) from the received imaging radiation beam 15, and a therapeutic radiation beam on the human body 1. 9 and a therapeutic radiation beam irradiator 7 for irradiating 9. Further, a control device 11 for controlling the imaging radiation beam irradiator 13 and the therapeutic radiation beam irradiator 7 is installed in the radiation therapy system. Here, the imaging radiation beam irradiator 13 and the imaging radiation beam detector 17 constitute a human body imaging device for imaging in the human body 1.

  Each component of such a radiotherapy system will be described in detail below with reference to FIGS.

  The therapeutic radiation beam irradiator 7 irradiates the tumor 3 in the human body 1 with the therapeutic radiation beam 9 as described above. Here, as the therapeutic radiation beam 9, for example, an X-ray beam having an energy in the range of 4 MV to 10 MV (1 MV is 1 million volts) is used. In particular, the therapeutic radiation beam irradiator 7 accelerates electrons by an electron accelerating portion provided therein, and generates a high energy X-ray beam by colliding the accelerated high energy electrons with a metal target. It is preferable to irradiate the human body 1 with this high-energy X-ray beam as a therapeutic radiation beam 9.

  The imaging radiation beam irradiator 13 irradiates the human body 1 with the imaging radiation beam 15. Specifically, the imaging radiation beam irradiator 13 includes the tumor 3 in the human body 1 in the irradiation range and is larger than the tumor 3 and is linked to the respiration of the human body, specifically, for example, the diaphragm The imaging radiation beam 15 is irradiated so as to include 5 as well. Here, the imaging radiation beam irradiator 13 accelerates electrons with a voltage of about 100 kV by an X-ray tube provided inside, and generates an X-ray beam by colliding the accelerated electrons with a metal target. The human body 1 is preferably irradiated with this X-ray beam as an imaging radiation beam 15.

  The imaging radiation beam detector 17 receives the imaging radiation beam 15 irradiated from the imaging radiation beam irradiator 13 and transmitted through the human body. For example, the flat panel type semiconductor two-dimensional array detector having amorphous silicon is used. Consists of. Further, the imaging radiation beam detector 17 generates a fluoroscopic image 25 as shown in FIG. 4 from the received imaging radiation beam 15. In the fluoroscopic image 25, the diaphragm 5 in the human body 1 is clearly imaged.

  Here, the fluoroscopic image 25 obtained by the imaging radiation beam irradiator 13 and the imaging radiation beam detector 17 will be described in more detail. As shown in FIG. 4, the fluoroscopic image 25 detected by the imaging radiation beam detector 17 is a wide range including the chest of the human body 1. Not suitable for performing calculations. For this reason, a portion including the diaphragm 5 in the fluoroscopic image 25 is cut out by a frame 27 (indicated by a white portion in the fluoroscopic image 25 in FIG. 4), and the boundary region of the diaphragm in the frame 27 is used for calculation in the control device 11. To do. Specifically, with respect to the image of the diaphragm 5 within the frame 27 of the fluoroscopic image 25, the gray scale as shown in FIG. 4 is rewritten to the boundary line 29 of the monochrome pattern as shown in FIG. FIG. 5 shows the boundary line 29 of the diaphragm 5 in various respiratory phases from the inspiratory period to the expiratory period. Of the plurality of boundary lines 29 in FIG. 5, the uppermost boundary line 29 is at the peak of the expiration period, and the lowermost boundary line 29 is at the peak of the inhalation period.

  6 shows the coordinates of the vertical axis of the boundary line 29 when the horizontal axis value of the graph of FIG. 5 is fixed with respect to the plurality of boundary lines 29 in FIG. 5 (that is, each time when the time has passed). As a plot of coordinates). From FIG. 6, it is possible to observe the periodic reciprocating state of the diaphragm 5 in the human body 1. In FIG. 6, the portion indicated by reference numeral 31 corresponds to the peak of the call period.

  As shown in FIG. 1, the therapeutic radiation beam irradiator 7, the imaging radiation beam irradiator 13, and the imaging radiation beam detector 17 are connected to a so-called donut-shaped rotating gantry mechanism 35. Further, the human body 1 is positioned along the central axis of the rotating gantry mechanism 35 when performing treatment, and the rotating gantry mechanism 35 is centered on the human body 1 disposed at such a position. It rotates in the direction of the arrow 1. Here, with respect to the rotating gantry mechanism 35, the therapeutic radiation beam 9 irradiated from the therapeutic radiation beam irradiator 7 and the imaging radiation beam 15 irradiated from the imaging radiation beam irradiator 13 are substantially perpendicular. Mounting positions of the therapeutic radiation beam irradiator 7 and the imaging radiation beam irradiator 13 are set (that is, the therapeutic radiation beam irradiator 7 and the imaging radiation beam irradiator 13 with respect to the central axis of the rotating gantry mechanism 35). The phase difference is about 90 °). In addition, the imaging radiation beam detector 17 is attached to the rotating gantry mechanism 35 so as to be opposite to the imaging radiation beam irradiator 13 with respect to the central axis of the rotating gantry mechanism 35.

  Here, as shown in FIG. 1, a movable bed 39 for placing the human body 1 is provided in the vicinity of the rotating gantry mechanism 35. Here, when the human body 1 is treated, the bed 39 on which the human body 1 is placed is moved in advance so that the human body 1 is positioned along the central axis of the rotating gantry mechanism 35. A display device 37 for displaying various treatment parameters is provided in the vicinity of the rotating gantry mechanism 35. The display device 37 displays various treatment parameters transmitted from the control device 11 (described later).

  Furthermore, the control apparatus 11 is provided in the radiotherapy system. The control device 11 is communicatively connected to the therapeutic radiation beam irradiator 7, the imaging radiation beam irradiator 13, and the imaging radiation beam detector 17 via cables 19, 23, and 21. FIG. 3 shows the contents of control by the control device 11. The control contents of the control device 11 will be roughly described. The control device 11 is configured so that a fluoroscopic image 25 inside the human body generated by the imaging radiation beam detector 17 is sent over time. When the image information of the fluoroscopic image 25 that is sent automatically matches the image information of the reference fluoroscopic image in a specific respiration phase (for example, at the peak of the inspiration period or expiratory period) that is generated in advance, the therapeutic radiation beam irradiation When the therapeutic radiation beam 9 is irradiated to the tumor 3 in the human body 1 by the device 7 and the image information of the fluoroscopic image 25 obtained from the imaging radiation beam detector 17 does not substantially match the image information of the reference fluoroscopic image, the treatment is performed. The therapeutic radiation beam 9 is not irradiated to the medical radiation beam irradiator 7. Details of control contents in the control device 11 will be described later.

  Next, the operation of the radiotherapy system having such a configuration will be described below. In addition, the control contents of the imaging radiation beam irradiator 13 and the therapeutic radiation beam irradiator 7 by the control device 11 will be described.

  First, before performing the treatment process of the human body 1, a treatment plan is created as shown in Step 1 of FIG. Specifically, a CT image inside the human body 1 (hereinafter referred to as a first CT image) is generated by a CT system different from the radiotherapy system as shown in FIGS. Here, when performing radiation therapy on a tumor 3 that reciprocates in conjunction with respiration, such as a lung tumor, the position of the tumor 3 differs by a few centimeters due to a change in the respiratory phase. For this reason, when preparing a treatment plan, it is necessary to take into account that the position of the tumor 3 differs depending on the respiratory phase. In the present embodiment, the respiratory phase is also detected when the first CT image is generated by using a displacement sensor provided on the body surface such as the chest and abdomen. Here, the reciprocation of the tumor 3 stops at the peak of the expiration period or the inhalation period, particularly at the peak of the expiration period. For this reason, at the peak time of the expiration period or the inhalation period, even if the timing of irradiation of the therapeutic radiation beam 9 with respect to the tumor 3 in actual treatment is slightly shifted, the movement of the tumor 3 is ignored. And safe irradiation of the radiation beam can be performed.

  In creating a treatment plan as shown in Step 1 of FIG. 3, in the present embodiment, the first CT image is obtained for a specific respiratory phase, specifically, for example, at the peak of the expiratory phase or the inspiratory phase (particularly at the peak of the expiratory phase). , And the irradiation direction and irradiation dose plan for the tumor 3 of the human body 1 of the therapeutic radiation beam 9 in a specific respiratory phase are created in advance. Here, it should be noted that the radiation dose varies depending on the irradiation direction of the therapeutic radiation beam 9 with respect to the tumor 3 of the human body 1 in preparing the radiation dose plan of the therapeutic radiation beam 9. Specifically, as shown in FIG. 12, when the therapeutic radiation beam 9 is applied to the tumor 3 of the human body 1, the therapeutic radiation beam 9 is transmitted before the therapeutic radiation beam 9 reaches the tumor 3. A part is absorbed by the tissue in the human body 1 (see the hatched portion in FIG. 12). Therefore, when the irradiation direction of the therapeutic radiation beam 9 on the tumor 3 is different, specifically, for example, the therapeutic radiation beam 9 is irradiated on the tumor 3 from the therapeutic radiation beam irradiator 7 'in FIG. Then, since the amount of the therapeutic radiation beam 9 absorbed by the tissue in the human body 1 is also different (the area of the hatched portion in FIG. 12 is different), the therapeutic radiation beam for the tumor 3 of the human body 1 is different. The irradiation dose must be changed according to the irradiation direction of 9. As described above, in the process of creating a treatment plan as shown in Step 1, the irradiation direction and irradiation dose plan for the tumor 3 of the human body 1 of the therapeutic radiation beam 9 in a specific respiratory phase in advance are taken into account in consideration of the above matters. Will be created.

  Note that the first CT image obtained in Step 1 is generally imaged, for example, only on the chest of the human body 1 due to the configuration of the CT system, and the position of the first CT image does not change due to respiration. Although organs are included, the diaphragm 5 is often not imaged. In the first CT image obtained in Step 1, the position of the tumor 3 in the first CT image is calculated based on the relative positional relationship with the organ.

  Further, instead of generating the first CT image inside the human body 1 with a CT system different from the radiation therapy system, the imaging radiation beam irradiator 13 and the imaging radiation of the radiation therapy system as shown in FIGS. 1 and 2 are used. A first CT image may be generated by the beam detector 17.

  Next, as shown in Step 2 of FIG. 3, the human body 1 is placed on the bed 39, and the human body 1 is positioned on the central axis of the rotating gantry mechanism 35 by moving the bed 39. A plurality of fluoroscopic images 25 (see FIG. 4) inside the human body 1 are generated by the imaging radiation beam irradiator 13 and the imaging radiation beam detector 17 while rotating in the direction of the arrow 1. Here, the fluoroscopic image 25 obtained in Step 2 is in various respiratory phases. A plurality of fluoroscopic images 25 obtained by the imaging radiation beam detector 17, specifically a plurality of breathing phases and a plurality of irradiation directions of the imaging radiation beam 15 on the human body 1 are varied. A fluoroscopic image 25 is sent to the control device 11 via the cable 21.

  Next, as shown in Step 3 of FIG. 3, the control device 11 generates a plurality of second CT images based on the plurality of fluoroscopic images 25 sent from the imaging radiation beam detector 17. Specifically, among the plurality of fluoroscopic images 25 having various respiratory phases, from the plurality of fluoroscopic images 25 having the same respiratory phase and various irradiation directions of the imaging radiation beam 15 on the human body 1, A second CT image is generated by the projection reconstruction method. The second CT image generated in this way is of a specific respiratory phase. Then, in each respiratory phase, specifically, in each of the 10 respiratory phases when the respiratory phase is divided into ten, by repeating the imaging by the projection reconstruction method as described above, a plurality of second phase in each respiratory phase is obtained. A 2CT image will be obtained.

  Next, as shown in Step 4 of FIG. 3, in the control device 11, one of the plurality of second CT images in each respiratory phase obtained in Step 3 is the one closest to the first CT image obtained in Step 1. A second CT image is selected. This one second CT image is a specific respiratory phase set when the treatment plan of Step 1 is created, specifically, for example, at the peak of the expiration period or the inhalation period. By selecting one second CT image in such a specific respiratory phase, the radiotherapy planned at the time of creating the treatment plan can be reproduced with the actual treatment. However, since only the second CT image having the highest relative position similarity between the contour of the human body 1 and the position of the tumor 3 is selected at this time, it is necessary to adjust the position of the bed 39. Specifically, the rotation center (isocenter) at the time of irradiation set on the first CT image at the time of creating the treatment plan and the image center of one second CT image selected in Step 4 are matched. Next, one CT image is translated in the three-axis direction so that the first CT image and the one second CT image most closely match, or one CT image is rotated around the three axes. Thus, the position and angle of the bed 39 can be corrected so that the image center of the second CT image coincides with the rotation center at the time of treatment planning. This Step 4 process is called positioning or alignment of the patient (human body 1).

  Next, as shown in Step 5, the fluoroscopic image 25 relating to the respiratory phase corresponding to the one second CT image selected in Step 4 is set as the reference fluoroscopic image. Here, such a reference fluoroscopic image has a plurality of various types depending on the irradiation direction of the imaging radiation beam 15 on the human body 1. A reference fluoroscopic image is generated for each gantry angle of the rotating gantry mechanism 35. . The plurality of reference fluoroscopic images corresponding to the respective gantry angles can be easily generated because those generated in Step 2 and stored in the control device 1 can be used as they are. Here, by rotating the rotating gantry mechanism 35 around the human body 1 a plurality of times at Step 2 and generating a fluoroscopic image 25 for a plurality of rotations, a reference fluoroscopic image corresponding to a specific gantry angle is obtained at Step 5. Troubles such as shortage can be prevented in advance.

  Alternatively, the control device 11 can generate a reference fluoroscopic image from the second CT image. Specifically, if the CT values of the traced pixels are added by tracing the trajectory of the imaging radiation beam 15 having a divergence angle emitted from the X-ray tube of the imaging radiation beam irradiator 13 by the ray tracing method. Good.

  In FIG. 3, the reference fluoroscopic image generation process according to Step 5 is performed after the alignment process according to Step 4. However, Step 4 and Step 5 may be executed in reverse order.

  Next, as shown in Step 6 of FIG. 3, irradiation of the therapeutic radiation beam 9 to the human body 1 by the therapeutic radiation beam irradiator 7 is started. At this time, by continuously applying the imaging radiation beam 15 from the imaging radiation beam irradiator 13 to the human body 1, a fluoroscopic image 25 inside the human body 1 is generated over time. Then, only when the image information of the fluoroscopic image 25 generated over time substantially matches the image information of the reference fluoroscopic image generated in Step 5, the therapeutic radiation is applied from the therapeutic radiation beam irradiator 7 to the human body 1. The beam 9 is irradiated. Here, the image information of the fluoroscopic image refers to the image in the frame 27 in the fluoroscopic image 25 as shown in FIG. 4, the boundary line 29 of the diaphragm 5 subjected to binarization processing as shown in FIG. 5, or FIG. The movement locus of the boundary line 29 of the diaphragm 5 on a specific straight line in which the value of the horizontal axis in the graph of FIG. As an index for evaluating the degree of coincidence of image information, a method using inner product calculation or cross-correlation calculation is known. For example, the image information of the fluoroscopic image 25 generated with time in Step 6 and the information generated in Step 5 are used. In addition, when the correlation value with the image information of the reference fluoroscopic image is 0.95 or more, it can be considered that the image information of both is substantially the same. In this way, the therapeutic radiation beam 9 can be irradiated to the human body 1 from the therapeutic radiation beam irradiator 7 only at the peak of the inhalation period or expiratory period, for example. In order to shorten the processing time when performing such calculation in the control device 11, it is effective to reduce the area of the fluoroscopic image in which the correlation calculation is performed or to reduce the spatial resolution of the image. is there.

  Finally, as shown in Step 7, the control device 11 determines whether or not the absorbed dose of the therapeutic radiation beam 9 in the tumor 3 has reached a preset amount determined in the treatment plan of Step 1. When the absorbed dose of the therapeutic radiation beam 9 in the tumor 3 does not reach the set amount, irradiation of the therapeutic radiation beam 9 to the human body 1 by the therapeutic radiation beam irradiator 7 as shown in Step 6 is continued. On the other hand, when the absorbed dose of the therapeutic radiation beam 9 in the tumor 3 reaches a set amount, the control device 11 detects that a series of treatments is completed.

  As described above, according to the radiation therapy system of the present embodiment as shown in FIGS. 1 to 6, when the tumor 3 in the human body 1 is treated, the imaging radiation beam irradiator 13 and the imaging radiation beam are used. A fluoroscope image 25 inside the human body 1 is generated over time by the detector 17, and the image information of the fluoroscopic image 25 generated over time is the image information of the reference fluoroscopic image in a specific respiratory phase generated in advance. Only when they substantially coincide, the therapeutic radiation beam irradiator 7 irradiates the tumor 3 in the human body 1 with the therapeutic radiation beam 9. Thus, although the position of the tumor 3 periodically changes due to the respiration of the human body 1, the therapeutic radiation beam 9 is irradiated to the tumor 3 only in a specific respiratory phase. The position of the tumor 3 at the time of irradiation is substantially the same, and the therapeutic radiation beam 9 can be accurately irradiated to the tumor 3 that periodically reciprocates.

  Here, when the specific breathing phase is set to the peak period of the expiration period or the inhalation period (especially the peak period of the expiration period), as shown in FIG. Since the tumor 3 temporarily stops at the peak time 31) of the period, the therapeutic radiation beam 9 can be irradiated to the tumor 3 with higher accuracy.

  Further, in the generation of the fluoroscopic image 25 over time in Step 6, the fluoroscopic image 25 including not only the tumor 3 but also the in-vivo reference portion such as the diaphragm 5 that interlocks with the respiration of the human body is generated. Then, when the diaphragm 5 in the fluoroscopic image 25 generated with time in Step 6 substantially coincides with the diaphragm 5 in the reference fluoroscopic image generated in Step 5, the control device 11 applies a therapeutic radiation beam to the tumor 3. 9 is irradiated. Here, in general, the diaphragm 5 is sufficiently larger than the tumor 3, and the diaphragm 5 is clearly depicted in the fluoroscopic image 25. For this reason, by using the position of the diaphragm 5 as the image information rather than using the position of the tumor 3 itself in the fluoroscopic image 25, the image information of the fluoroscopic image 25 generated over time in Step 6 and the generation in Step 5 are more accurately performed. The comparison with the image information of the reference fluoroscopic image in the specified specific respiratory phase can be performed.

  In addition, the radiotherapy system by this Embodiment is not limited to said aspect, A various change can be added. 7 to 9 are schematic configuration diagrams showing other configurations of the radiation therapy system according to the present invention.

Specifically, the radiotherapy system as shown in FIGS. 7 to 9 continuously applies the therapeutic radiation beam to the tumor instead of irradiating the tumor with the therapeutic radiation beam only during a specific respiratory phase. The only difference is that the irradiation position is changed over time so that the irradiation position of the therapeutic radiation beam follows the tumor that is irradiated periodically and that moves periodically. It has the same configuration as the radiation therapy system as shown in FIG.
In the description of the modification of the radiotherapy system as shown in FIGS. 7 to 9, the same parts as those of the radiotherapy system as shown in FIGS.

  In the radiotherapy system according to this modification as shown in FIG. 7, a multi-leaf collimator 33 for changing the irradiation position of the therapeutic radiation beam 9 irradiated from the therapeutic radiation beam irradiator 7 is additionally installed. Has been. The multi-leaf collimator 33 is communicatively connected to the control device 11 via a cable 43. The multi-leaf collimator 33 can change the irradiation position of the therapeutic radiation beam 9 irradiated from the therapeutic radiation beam irradiator 7 over time based on a control signal from the control device 11. Yes.

  The multi-leaf collimator 33 will be specifically described with reference to FIG. As shown in FIG. 8, the multi-leaf collimator 33 has a large number of shielding plates 33s made of tungsten. Each shielding plate (also referred to as a leaf) 33s has a size in the range of 5 mm to 1 cm in the vertical direction in FIG. 8, and a thickness in the depth direction in FIG. 8 is about 8 cm. Each shielding plate 33s can be moved in a one-dimensional direction, that is, in the left-right direction in FIG. 8, independently from the other shielding plates 33s by a motor (not shown). In FIG. 8, when the multi-leaf collimator 33 has an aspect like the upper-stage multi-leaf collimator 33a, the therapeutic radiation beam 9 emitted from the therapeutic radiation beam irradiator 7 is completely blocked, and the human body 1 is not irradiated with the therapeutic radiation beam 9. Here, when a pair of left and right shielding plates 33s are opened in the arrow direction (left and right) in the upper multi-leaf collimator 33a, as shown in the middle multi-leaf collimator 33b, an opening portion (black in FIG. 8). A coating portion) is formed, and the therapeutic radiation beam 9 passes through this opening portion. Further, when the irradiation position of the therapeutic radiation beam 9 on the human body 1 is changed, the pair of left and right shielding plates 33 s move in the arrow direction (both to the left) in the middle multi-leaf collimator 33 b in FIG. In this way, the opening moves as shown in the lower multi-leaf collimator 33c in FIG. As described above, the aspect of the multi-leaf collimator 33 changes in accordance with the movement of the tumor 3, and specifically, each shielding plate 33 s moves appropriately, so that the irradiation position of the therapeutic radiation beam 9 on the human body 1 can be changed. Can be varied. Here, such control of the multi-leaf collimator 33 is based on a control signal from the control device 11.

  The control contents of the control device 11 in the radiotherapy system according to this modification will be roughly described. The control device 11 transmits the fluoroscopic image 25 inside the human body generated by the imaging radiation beam detector 17 with time. By controlling the multi-leaf collimator 33 based on the image information of the fluoroscopic image 25 sent over time and the reference fluoroscopic images in various respiratory phases generated in advance, the inside of the human body 1 The irradiation position is changed over time so that the irradiation position of the therapeutic radiation beam 9 irradiated from the therapeutic radiation beam irradiator 7 is made to follow the tumor 3.

  Next, the operation of the radiotherapy system as shown in FIGS. 7 and 8 will be described below. In addition, the control contents of the imaging radiation beam irradiator 13, the therapeutic radiation beam irradiator 7, the multi-leaf collimator 33 and the like by the control device 11 will be described with reference to FIG. 9. In the description of this control content, detailed description of the same parts as the control content as shown in FIG. 3 is omitted.

  First, before performing the treatment process of the human body 1, a treatment plan is created as shown in Step 1 of FIG. Specifically, a CT image inside the human body 1 (hereinafter referred to as a first CT image) is generated. Here, unlike the treatment plan creation step by Step 1 of FIG. 3, Step 1 of FIG. 9 generates a plurality of first CT images in various respiratory phases. And the plan of the irradiation direction and irradiation dose with respect to the tumor 3 of the human body 1 of the therapeutic radiation beam 9 is prepared in advance for each of various respiratory phases. Here, when creating the radiation dose plan for the therapeutic radiation beam 9, if the respiratory phase is different, the relationship between the irradiation direction of the therapeutic radiation beam 9 on the tumor 3 of the human body 1 and the radiation dose changes. It should be noted. Specifically, as shown in FIG. 13, when the therapeutic radiation beam 9 is applied to the tumor 3 of the human body 1, the irradiation direction of the therapeutic radiation beam 9 on the tumor 3 of the human body 1 is the same. Even so, the amount of the therapeutic radiation beam 9 absorbed by the tissue in the human body 1 varies depending on the position of the tumor 3 that changes depending on the respiratory phase (see the hatched portion in FIG. 13). FIG. 13 is a diagram schematically showing the irradiation of the therapeutic radiation beam 9 from the same direction at the peak of the expiration period and the peak of the inhalation period. As described above, in the process of creating the treatment plan as shown in Step 1 of FIG. 9, the irradiation direction and the irradiation dose of the therapeutic radiation beam 9 in various respiratory phases of the tumor 3 of the human body 1 in various respiratory phases are also taken into consideration. A plan is created in advance for each respiratory phase.

  Next, as shown in Step 2 of FIG. 9, a fluoroscopic image 25 (inside the body of the human body 1) by the imaging radiation beam irradiator 13 and the imaging radiation beam detector 17 while rotating the rotating gantry mechanism 35 around the human body 1. A plurality of data are generated (see FIG. 4). Here, the fluoroscopic image 25 obtained in Step 2 is in various respiratory phases.

  Next, as shown in Step 3 of FIG. 9, a plurality of second CT images in each respiratory phase are generated based on the plurality of fluoroscopic images 25 generated in Step 2. Such a method for generating a plurality of second CT images is substantially the same as the method according to Step 3 in FIG. 3 (specifically, the projection reconstruction method).

  Next, as shown in Step 4 of FIG. 9, in the control device 11, a plurality of first CT images obtained in Step 1 for one second CT image among a plurality of second CT images in each respiratory phase obtained in Step 3. The first CT image that is most approximated is selected. Then, the position of the bed 39 is adjusted based on the first CT image and the second CT image which are related to each other. Specifically, the rotation center (isocenter) at the time of irradiation set on one first CT image at the time of creating a treatment plan is made to coincide with the image center of one second CT image. Next, one CT image is translated in the direction of three axes so that one first CT image and one second CT image most closely match, or one CT image is rotated around the three axes. Thus, the position or angle of the bed 39 can be corrected so that the image center of the second CT image coincides with the rotation center at the time of treatment planning. In this way, the patient (human body 1) is positioned (or aligned).

  Next, as shown in Step 5 of FIG. 9, the second CT images that are closest to each of the first CT images of the plurality of first CT images generated in Step 1 and the plurality of second CT images generated in Step 3. And the perspective image 25 related to the second CT image is associated. That is, the first CT image and the second CT image are associated with each other in various respiratory phases from the peak of the expiratory phase to the peak of the inspiratory phase, and thereby used to generate the second CT image in each respiratory phase. The perspective images 25 of various gantry angles are associated with the first CT image. Here, the fluoroscopic image 25 associated with the first CT image is set as a reference fluoroscopic image.

  Next, as shown in Step 6 of FIG. 9, irradiation of the therapeutic radiation beam 9 to the human body 1 by the therapeutic radiation beam irradiator 7 is started. Here, unlike Step 6 of FIG. 3, the human body 1 is continuously irradiated with the therapeutic radiation beam 9 without interruption. At this time, by continuously applying the imaging radiation beam 15 from the imaging radiation beam irradiator 13 to the human body 1, a fluoroscopic image 25 inside the human body 1 is generated over time. Then, the image information of the fluoroscopic image 25 generated with time and the image information of each reference fluoroscopic image related to the plurality of first CT images in various respiratory phases are compared, and the closest reference image information is supported. Based on the first CT image, the irradiation position of the therapeutic radiation beam 9 is changed over time by the multi-leaf collimator 33. Specifically, the corresponding first CT images in various respiratory phases are set in Step 1, but the corresponding first CT images are selected by the fluoroscopic image 25 generated by the imaging radiation beam detector 17 in Step 6. Since it is possible, the respiratory phase regarding this 1st CT image can be specified. As a result, the position of the tumor 3 corresponding to this respiratory phase can be specified from the first CT image, so that the irradiation position of the therapeutic radiation beam 9 follows this tumor 3. The irradiation position can be changed by the multi-leaf collimator 33. Here, when the irradiation position of the therapeutic radiation beam 9 is made to follow the tumor 3 that periodically moves back and forth, as described above, even if the gantry angle is the same for different therapeutic phases, Although the irradiation dose of the radiation beam 9 is different, the irradiation direction of the therapeutic radiation beam 9 on the tumor 3 of the human body 1 for each respiratory phase in Step 1 and the plurality of first CT images related to various respiratory phases and Since the irradiation dose plan is created, the irradiation direction and irradiation dose of the therapeutic radiation beam 9 can be made appropriate even when the respiratory phase changes.

  Finally, as shown in Step 7, the control device 11 determines whether or not the absorbed dose of the therapeutic radiation beam 9 in the tumor 3 has reached a preset amount determined in the treatment plan of Step 1. When the absorbed dose of the therapeutic radiation beam 9 in the tumor 3 does not reach the set amount, irradiation of the therapeutic radiation beam 9 to the human body 1 by the therapeutic radiation beam irradiator 7 as shown in Step 6 is continued. On the other hand, when the absorbed dose of the therapeutic radiation beam 9 in the tumor 3 reaches a set amount, the control device 11 detects that a series of treatments is completed.

  As described above, according to the radiotherapy system as shown in FIGS. 7 to 9, when the tumor 3 in the human body 1 is treated, the imaging radiation beam irradiator 13 and the imaging radiation beam detector 17 perform the human body. 1 is generated over time, and based on the image information of the fluoroscopic image 25 generated over time and the image information of the reference fluoroscopic image in each respiratory phase generated in advance, The irradiation position is changed with time so that the irradiation position of the therapeutic radiation beam 9 irradiated from the radiation beam irradiator 7 follows the tumor 3 in the human body 1. Thus, although the position of the tumor 3 periodically changes due to the respiration of the human body 1, the tumor is always changed by changing the irradiation position of the therapeutic radiation beam 9 corresponding to the change in the position of the tumor 3. Therefore, the therapeutic radiation beam 9 can be accurately irradiated to the tumor 3 that periodically reciprocates.

  In the radiotherapy system in which the control as shown in FIG. 9 is performed, the mechanism for changing the irradiation position of the therapeutic radiation beam 9 is not limited to the multi-leaf collimator 33, and other types of collimators are used. May be. In addition to the collimator, various types of irradiation position changing mechanisms can be used as long as the irradiation position of the therapeutic radiation beam 9 can be changed over time.

  Next, still another configuration of the radiotherapy system according to the present invention will be described with reference to FIGS. 10 and 11.

Specifically, the radiotherapy system as shown in FIGS. 10 and 11 is different from the radiotherapy system as shown in FIGS. 7 to 9 in that the therapeutic radiation beam is applied to a periodically moving tumor. Instead of changing the irradiation position over time to follow the irradiation position, the only difference is that the bed on which the human body is placed is moved over time according to the periodic movement of the tumor. 7 to 9 have the same configuration as that of the radiotherapy system shown in FIGS.
10 and 11, in the description of the modification of the radiation therapy system, the radiation therapy system as shown in FIGS. 1 to 3 or the same part as the radiation therapy system as shown in FIGS. Are denoted by the same reference numerals, and detailed description thereof is omitted.

  The control contents of the control device 11 in the radiotherapy system according to this modification will be roughly described. The control device 11 transmits the fluoroscopic image 25 inside the human body generated by the imaging radiation beam detector 17 with time. Based on the image information of the fluoroscopic image 25 sent over time and the reference fluoroscopic images in various respiratory phases generated in advance, the therapeutic radiation beam irradiated from the therapeutic radiation beam irradiator 7 is used. The bed 39 is moved with time so that the radiation beam 9 always irradiates the tumor 3 in the human body 1. The bed 39 is communicatively connected to the control device 11 as shown in FIG.

  Hereinafter, the control contents of the imaging radiation beam irradiator 13, the therapeutic radiation beam irradiator 7, the bed 39 and the like by the control device 11 will be described with reference to FIG. 11. In the description of this control content, detailed description of the same parts as the control content as shown in FIG. 9 is omitted.

  First, before performing the treatment process of the human body 1, a treatment plan is created as shown in Step 1 of FIG. 11. Specifically, a CT image inside the human body 1 (hereinafter referred to as a first CT image) is generated. Here, similarly to the treatment plan creation step by Step 1 of FIG. 9, Step 1 of FIG. 11 generates a plurality of first CT images in various respiratory phases. Further, in Step 1 of FIG. 11, similarly to the treatment plan creation step in Step 1 of FIG. 9, the irradiation direction and irradiation dose plan for the tumor 3 of the human body 1 of the therapeutic radiation beam 9 in various respiratory phases are determined for each respiration. Each phase is created in advance. Further, in Step 1 of FIG. 11, for each first CT image in each respiratory phase, the reference point coordinates of the tumor 3, specifically, coordinates related to the center of gravity of the tumor 3 are set, and the set coordinates are controlled. It is stored in the device 11.

  Next, as shown in Step 2 of FIG. 11, a fluoroscopic image 25 (inside the body of the human body 1) by the imaging radiation beam irradiator 13 and the imaging radiation beam detector 17 while rotating the rotating gantry mechanism 35 around the human body 1. A plurality of data are generated (see FIG. 4). Here, the fluoroscopic image 25 obtained in Step 2 is in various respiratory phases.

  Next, as shown in Step 3 of FIG. 11, a plurality of second CT images in each respiratory phase are generated based on the plurality of fluoroscopic images 25 generated in Step 2. Such a method for generating a plurality of second CT images is substantially the same as the method according to Step 3 in FIG. 3 (specifically, the projection reconstruction method).

  Next, as shown in Step 4 of FIG. 11, in the control device 11, a plurality of first CT images obtained in Step 1 for one second CT image among a plurality of second CT images in each respiratory phase obtained in Step 3. The first CT image that is most approximated is selected. Then, the initial position of the bed 39 is adjusted based on the first CT image and the second CT image that are related to each other. Here, the setting method of the initial position of the bed 39 is substantially the same as the method according to Step 3 of FIG.

  Next, as shown in Step 5 of FIG. 11, the second CT images that are closest to each of the first CT images of the plurality of first CT images generated in Step 1 and the plurality of second CT images generated in Step 3. And the perspective image 25 related to the second CT image is associated. That is, the first CT image and the second CT image are associated with each other in various respiratory phases from the peak of the expiratory phase to the peak of the inspiratory phase, and thereby used to generate the second CT image in each respiratory phase. The perspective images 25 of various gantry angles are associated with the first CT image. Here, the fluoroscopic image 25 associated with the first CT image is set as a reference fluoroscopic image.

  Next, as shown in Step 6 of FIG. 11, irradiation of the therapeutic radiation beam 9 to the human body 1 by the therapeutic radiation beam irradiator 7 is started. Here, similarly to Step 6 in FIG. 9, the human body 1 is continuously irradiated with the therapeutic radiation beam 9 without interruption. At this time, by continuously applying the imaging radiation beam 15 from the imaging radiation beam irradiator 13 to the human body 1, a fluoroscopic image 25 inside the human body 1 is generated over time. Then, the image information of the fluoroscopic image 25 generated with time and the image information of each reference fluoroscopic image related to the plurality of first CT images in various respiratory phases are compared, and the closest reference image information is supported. Based on the first CT image, the reference point coordinates set so as to correspond to the first CT image are calculated. Then, the bed 39 on which the human body 1 is placed so that the irradiation position of the therapeutic radiation beam 9 irradiated from the therapeutic radiation beam irradiator 7 is located at the reference point coordinates set corresponding to the first CT image. Are moved over time. Specifically, the control device 11 translates the bed 39 in the three-axis directions and rotates the bed 39 around the three axes, thereby moving the bed 39 to an appropriate place, that is, the therapeutic radiation beam irradiator 7. Thus, the therapeutic radiation beam 9 irradiated from is always located at a location where the therapeutic radiation beam 9 always hits the tumor 3 of the human body 1. Here, in the case where the irradiation position of the therapeutic radiation beam 9 is made to follow the tumor 3 that periodically moves back and forth, as described above, even if the gantry angle is the same if the respiratory phase is different, the therapeutic radiation beam 9, the irradiation direction and the irradiation dose of the therapeutic radiation beam 9 with respect to the tumor 3 of the human body 1 for each respiratory phase in Step 1 for a plurality of first CT images related to various respiratory phases. Therefore, even if the respiratory phase changes, the irradiation direction and irradiation dose of the therapeutic radiation beam 9 can be made appropriate.

  Finally, as shown in Step 7, the control device 11 determines whether or not the absorbed dose of the therapeutic radiation beam 9 in the tumor 3 has reached a preset amount determined in the treatment plan of Step 1. When the absorbed dose of the therapeutic radiation beam 9 in the tumor 3 does not reach the set amount, irradiation of the therapeutic radiation beam 9 to the human body 1 by the therapeutic radiation beam irradiator 7 as shown in Step 6 is continued. On the other hand, when the absorbed dose of the therapeutic radiation beam 9 in the tumor 3 reaches a set amount, the control device 11 detects that a series of treatments is completed.

  As described above, according to the radiation therapy system as shown in FIGS. 10 and 11, when the tumor 3 in the human body 1 is treated, the imaging radiation beam irradiator 13 and the imaging radiation beam detector 17 perform the human body. 1 is generated over time, and based on the image information of the fluoroscopic image 25 generated over time and the image information of the reference fluoroscopic image in each respiratory phase generated in advance, The bed 39 is moved with time so that the therapeutic radiation beam 9 emitted from the radiation beam irradiator 7 always irradiates the tumor 3 in the human body 1. Thus, although the position of the tumor 3 periodically changes due to the respiration of the human body 1, the therapeutic radiation beam is always applied to the tumor 3 by moving the bed 39 corresponding to the change in the position of the tumor 3. Therefore, the therapeutic radiation beam 9 can be accurately irradiated to the tumor 3 that periodically reciprocates.

It is a schematic perspective view which shows the structure of the radiotherapy system in one embodiment of this invention. It is a schematic block diagram of the radiotherapy system shown in FIG. It is a block diagram which shows the control content in the control apparatus of the radiotherapy system shown in FIG. 1, FIG. 3 is a perspective image of the inside of a human body obtained by the in-vivo imaging device of the radiotherapy system shown in FIGS. 1 and 2. It is a figure which shows the position fluctuation | variation of the diaphragm in the fluoroscopic image shown in FIG. It is a figure which shows the respiration phase calculated | required from the position fluctuation | variation of the diaphragm shown in FIG. It is a schematic perspective view which shows the structure of the other radiotherapy system in this invention. It is a schematic block diagram of the multileaf collimator in the radiotherapy system shown in FIG. It is a block diagram which shows the control content in the control apparatus of the radiotherapy system shown to FIG. 7, FIG. It is a schematic perspective view which shows the structure of the other radiotherapy system in this invention. It is a block diagram which shows the control content in the control apparatus of the radiotherapy system shown in FIG. It is a figure which shows typically the irradiation state of the therapeutic radiation beam with respect to the tumor in a human body. It is a figure which shows typically the irradiation state of the therapeutic radiation beam with respect to the tumor in a human body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Human body 3 Tumor 5 Diaphragm 7, 7 'Treatment radiation beam irradiation device 9 Treatment radiation beam 11 Control apparatus 13 Imaging radiation beam irradiation device 15 Imaging radiation beam 17 Imaging radiation beam detector 19, 21, 23 Cable 25 Perspective image 27 Frame 29 Boundary line 31 Peak period 33 Multi-leaf collimator 33s Shield plate 35 Rotating gantry mechanism 37 Display device 39 Bed 43 Cable

Claims (15)

A radiation treatment system for treating a treatment target portion by irradiating the treatment target portion in a human body with a radiation beam,
A human body imaging device that generates a fluoroscopic image inside the human body by irradiating the human body with an imaging radiation beam;
A therapeutic radiation beam irradiation apparatus for irradiating the human body with a therapeutic radiation beam; and
A control device for controlling the human body imaging device and the therapeutic radiation beam irradiation device, wherein the human body imaging device generates a fluoroscopic image inside the human body over time, and the fluoroscopic image generated over time When the image information of the image substantially coincides with the image information of the reference fluoroscopic image in the specific respiratory phase generated in advance, the therapeutic radiation beam is irradiated to the treatment target portion in the human body by the therapeutic radiation beam irradiation device. A control device that performs such control,
A radiation therapy system comprising:   The radiotherapy system according to claim 1, wherein the specific respiration phase of the reference fluoroscopic image generated in advance in the control device is a peak time of an expiration period or an inhalation period. The human body imaging device is configured to generate a fluoroscopic image including each of the treatment target portion and a body reference portion that is larger than the treatment target portion and interlocks with the respiration of the human body,
When the in-vivo reference portion in the fluoroscopic image generated over time substantially matches the in-vivo reference portion in the reference fluoroscopic image, the control device treats the treatment target portion in the human body by the therapeutic radiation beam irradiation device. 3. The radiotherapy system according to claim 1, wherein control is performed so as to irradiate a radiation beam for medical use.   The radiotherapy system according to claim 3, wherein the internal body reference portion is a diaphragm in a human body.   In the control device, the first CT image inside the human body in a specific respiratory phase is input in advance before the treatment of the human body, and the inside of the human body is changed while changing the irradiation direction of the imaging radiation beam to the human body by the human body imaging device. A plurality of fluoroscopic images are generated, a plurality of second CT images in various respiratory phases are generated based on the plurality of fluoroscopic images, and the first CT image is most approximated from the plurality of second CT images. The second CT image is selected, and the fluoroscopic image related to the respiratory phase corresponding to the one second CT image is set as the reference fluoroscopic image. A radiation therapy system according to claim 1.   The control device is configured to generate a second CT image from a plurality of fluoroscopic images at the same respiration phase by a projection reconstruction method when performing the setting of a reference fluoroscopic image. 5. The radiation therapy system according to 5. A mounting table for mounting a human body is further provided, and the position of the mounting table is set in advance in a certain place by the control device,
The control device, when performing the setting of the reference fluoroscopic image, is based on a positional deviation amount between one second CT image that is most approximate to the first CT image among the plurality of second CT images and the first CT image. 7. The radiation therapy system according to claim 5, wherein the position of the mounting table is preset. A radiation treatment system for treating a treatment target portion by irradiating the treatment target portion in a human body with a radiation beam,
A human body imaging device that generates a fluoroscopic image inside the human body by irradiating the human body with an imaging radiation beam;
A therapeutic radiation beam irradiation apparatus for irradiating a human body with a therapeutic radiation beam, the therapeutic radiation beam irradiation apparatus capable of changing the irradiation position of the therapeutic radiation beam;
A control device for controlling the human body imaging device and the therapeutic radiation beam irradiation device, wherein the human body imaging device generates a fluoroscopic image inside the human body over time, and the fluoroscopic image generated over time The irradiation position of the therapeutic radiation beam emitted from the therapeutic radiation beam irradiation apparatus follows the treatment target portion in the human body based on the image information of the reference and the image information of the reference fluoroscopic image in each respiratory phase generated in advance. A control device that performs control to change the irradiation position with time so as to
A radiation therapy system comprising:   9. The radiation treatment system according to claim 8, wherein the therapeutic radiation beam irradiation apparatus includes a collimator, and the collimator changes the irradiation position of the therapeutic radiation beam.   The radiotherapy system according to claim 9, wherein the collimator is a multi-leaf collimator.   In the control device, a plurality of first CT images inside the human body in various respiratory phases are input in advance before treatment of the human body, and the human body is changed while the irradiation direction of the imaging radiation beam to the human body is changed by the human body imaging device. A plurality of fluoroscopic images are generated, a plurality of second CT images in various respiratory phases are generated based on the plurality of fluoroscopic images, and the plurality of second CT images are compared with the plurality of first CT images. Then, the fluoroscopic image related to the second CT image that is the most approximate for each first CT image is related to the reference fluoroscopic image, and when the therapeutic radiation beam is irradiated to the human body by the therapeutic radiation beam irradiation device, the human body imaging is performed. Image information relating to a fluoroscopic image inside the human body obtained by the apparatus, and images of each reference fluoroscopic image respectively associated with the plurality of first CT images The control is performed such that the irradiation position of the therapeutic radiation beam irradiated from the therapeutic radiation beam irradiation apparatus is changed over time based on the first CT image related to the closest approximate image information. The radiation therapy system according to claim 8, wherein the radiation therapy system is configured as follows. A mounting table for mounting a human body is further provided, and the position of the mounting table is set in advance in a certain place by the control device,
The control device approximates the second CT image of one of the plurality of second CT images obtained by the human body imaging device most closely before the therapeutic radiation beam is irradiated onto the human body by the therapeutic radiation beam irradiation device. The radiotherapy system according to claim 11, wherein the position of the mounting table is set in advance based on a positional deviation amount between the first CT image and the second CT image. A radiation treatment system for treating a treatment target portion by irradiating the treatment target portion in a human body with a radiation beam,
A mounting table for mounting the human body;
A human body imaging device that generates a fluoroscopic image inside the human body by irradiating the human body mounted on the mounting table with an imaging radiation beam;
A therapeutic radiation beam irradiation apparatus for irradiating the human body mounted on the mounting table with a therapeutic radiation beam;
A control device for controlling the mounting table, the human body imaging device, and the therapeutic radiation beam irradiation device, wherein the human body imaging device generates a fluoroscopic image inside the human body over time, and the time generation The therapeutic radiation beam emitted from the therapeutic radiation beam irradiation device is based on the image information of the fluoroscopic image to be performed and the image information of the reference fluoroscopic image in each respiratory phase generated in advance before the treatment of the human body. A control device that controls to move the mounting table over time so as to always irradiate the treatment target part of
A radiation therapy system comprising:   In the control device, a plurality of first CT images inside the human body in various respiratory phases and coordinates of a treatment target portion corresponding to each first CT image are input in advance before treatment of the human body, and the human body imaging device A plurality of fluoroscopic images inside the human body are generated while changing the irradiation direction of the imaging radiation beam to the human body, a plurality of second CT images in various respiratory phases are generated based on the plurality of fluoroscopic images, The second CT image is compared with the plurality of first CT images, and the fluoroscopic image related to the second CT image that is most approximate for each first CT image is associated with the reference CT image, and the human body is treated by the therapeutic radiation beam irradiation apparatus. When irradiating a radiation beam for medical use, image information relating to a fluoroscopic image inside the human body obtained by the human body imaging device, and the plurality of The image information of each reference fluoroscopic image associated with each 1CT image is compared, and the above-mentioned mounting table is changed over time based on the coordinates of the treatment target portion corresponding to the first CT image related to the most approximate image information. The radiotherapy system according to claim 13, which is configured as described above.   The control device approximates the second CT image of one of the plurality of second CT images obtained by the human body imaging device most closely before irradiating the human body with the therapeutic radiation beam by the therapeutic radiation beam irradiation device. The radiotherapy system according to claim 13 or 14, wherein an initial position of the mounting table is set based on a positional deviation amount between the first CT image and the one second CT image.