JP2007037629A - Radiotherapy apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiotherapy apparatus achieving a specific configuration that allows a user to control a radiation region in response to fluctuations of an affected area and improves the radiation precision. <P>SOLUTION: A particle beam treatment apparatus 1 is provided which radiates, for example, an ion beam to an affected area 3a of a patient 3. The particle beam treatment apparatus comprises a beam generator 4, a radiation field generater 6 for radiating the ion beam from the beam generator 4 in the shape of the affected area 3a and having a patient collimator 23, a patient bolus 24 and a driving device 26 for moving the patient collimator 23 and the patient bolus 24, an affected area detector 7 for detecting fluctuations of the affected area 3a, and a control system 8 for driving and controlling the driving device 26 of the radiation field generator 6 in accordance with the detection result of the affected area detector 7. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a radiotherapy apparatus that performs treatment by irradiating an affected area of a patient with radiation.

  2. Description of the Related Art Radiotherapy apparatuses that perform treatment by irradiating an affected part of a patient with radiation (for example, an ion beam such as a proton beam or a heavy particle beam or an X-ray) are known. For example, a particle beam therapy system that irradiates an ion beam includes a beam generator, a beam transport system that transports an ion beam generated by the beam generator, and an irradiation field forming device connected to the beam transport system. Yes. The beam generation device accelerates the ion beam with an accelerator such as a synchrotron to raise it to a set energy (for example, 250 MeV), and then emits the beam to a beam transport system. In the irradiation field forming apparatus, the irradiation direction is determined by a rotating gantry, and an ion beam from a beam transport system is formed in an affected part shape and irradiated.

  In the planning stage of particle beam therapy, the affected area of a patient is measured from a CT image obtained by an image diagnostic apparatus such as an X-ray CT apparatus, and based on this, ion beam irradiation conditions (irradiation direction, irradiation range, and irradiation) are measured. Time). At this time, it is important to concentrate a large dose on the affected tissue while suppressing irradiation of the normal tissue of the patient as much as possible. However, the position and shape of the affected area often change due to body movements such as the patient's respiratory motion.

  In view of this, for the purpose of improving the accuracy of radiotherapy, a detection device that detects rotation and position change of an affected part caused by body movement such as a respiratory motion of a patient has been proposed (for example, see Patent Document 1). This detection device is provided with, for example, three angular velocity detectors in the affected part in the body, a receiver that receives detection signals from these angular velocity detectors is provided outside the body, and the affected part is rotated based on the detection signal received by the receiver. The displacement (rotation angle) is calculated. In addition, for example, one transmitter is provided at the affected part in the body, and for example, four transmitters / receivers for receiving and transmitting wave signals from the transmitter are provided on the body surface, and wave signals from these transmitters / receivers are respectively received. Four receivers are provided outside the body, and a change in the position of the transmitter provided in the affected area is calculated based on the wave signal received by these receivers. Then, the rotational displacement of the affected area is subtracted from the calculated position change of the transmitter, and the displacement due to the parallel movement of the affected area is calculated. Radiation irradiation conditions are determined based on the rotation and position change of the affected part obtained in this way, and based on this, the energy of the accelerator, the size of the irradiation range, the position and direction of the rotating gantry, and the treatment bed Control position and direction.

Japanese Patent No. 3304441

However, there are the following problems in the above-described prior art.
That is, in the prior art described in Patent Document 1, a detection device is disclosed in which an affected part is provided with an angular velocity detector, a transmitter, or the like to detect a change (temporal position change) of the affected part. The specific configuration for controlling the radiation irradiation range corresponding to the detection result is not clearly shown.

  The present invention has been made on the basis of the above matters, and its purpose is to realize a specific configuration capable of controlling the radiation irradiation range following the change of the affected area, thereby improving the irradiation accuracy. It is an object of the present invention to provide a radiotherapy apparatus that can perform the above-described process.

  (1) In order to achieve the above object, the present invention provides a radiation therapy apparatus for irradiating an affected area of a patient with a radiation generator, a collimator, and a drive device for moving the collimator, and the radiation generator Driving control of the irradiation field forming apparatus according to the detection result of the affected area detecting means, and the affected area detecting means for detecting the variation of the affected area Control means.

  In the present invention, a change in the affected part due to body movement such as a respiratory motion of the patient is detected by the affected part detection means. And according to the detection result of this affected part detection means, a control means drives and controls the drive device of an irradiation field forming apparatus, and moves a collimator. Specifically, for example, when the affected part is translated in the horizontal direction, the collimator is moved in a direction perpendicular to the traveling direction of the radiation to translate the radiation irradiation range. For example, when the affected part rotates, the collimator is rotated about the radiation traveling direction as the rotation axis, and the radiation irradiation range is rotated. Thereby, it is possible to make the affected affected area coincide with the radiation irradiation range. Thus, in the present invention, it is possible to realize a specific configuration capable of controlling the irradiation range of the radiation following the change of the affected part, thereby improving the irradiation accuracy.

  (2) In order to achieve the above object, the present invention has a radiation generating apparatus, a collimator, a bolus, and a driving device for moving the collimator and the bolus in a radiotherapy apparatus that irradiates an affected area of a patient. An irradiation field forming device that forms and irradiates the radiation from the radiation generating device in the shape of the affected part, an affected part detection unit that detects a change in the affected part, and a detection result of the affected part detection unit. Control means for driving and controlling the drive device.

  (3) In the above (2), preferably, the drive device of the irradiation field forming device has a drive mechanism for moving the collimator and the bolus as a unit.

  (4) In any one of the above (1) to (3), preferably, the driving device of the irradiation field forming device moves the collimator or / and the bolus in a direction perpendicular to the traveling direction of the radiation. It has a drive mechanism.

  (5) In any one of the above (1) to (3), and preferably, the drive device of the irradiation field forming device rotates the collimator and / or the bolus with the radiation traveling direction as an axis. It has a mechanism.

  (6) In any one of the above (1) to (5), preferably, irradiation stop means for stopping the irradiation of radiation when the variation of the affected area detected by the affected area detection means deviates from a predetermined setting range. Further prepare.

  For example, when the variation of the affected area is too large, even if the collimator or the bolus is moved correspondingly to control the radiation irradiation range, the irradiation accuracy may be lowered. Therefore, in the present invention, when the variation of the affected part detected by the affected part detection unit deviates from a predetermined setting range, the irradiation stop unit stops the radiation irradiation. Thereby, the irradiation accuracy of radiation can be further increased.

  According to the present invention, it is possible to realize a specific configuration capable of controlling the irradiation range of the radiation following the change of the affected part, thereby improving the irradiation accuracy.

Hereinafter, a particle beam therapy system which is a preferred embodiment of a radiotherapy system of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram showing the overall configuration of the particle beam therapy system according to this embodiment, and FIG. 2 is a schematic diagram showing the detailed structure of the irradiation field forming device provided in the particle beam therapy system according to this embodiment together with related devices. FIG.

  1 and 2, a particle beam treatment apparatus 1 irradiates an affected part 3 a of a patient 3 fixed to a treatment bed 2 with an ion beam (for example, a proton beam), and a beam generation apparatus 4 (radiation generation apparatus). ), A beam transport system 5 that transports the ion beam generated by the beam generator 4, and an irradiation field forming device 6 that is connected to the beam transport system 5 and forms and irradiates the ion beam in the shape of the affected part 3a, An affected area detection device 7 that detects a change in the affected area 3a due to body movement such as respiratory motion of the patient 3 and a control system 8 that controls beam irradiation according to the detection result of the affected area detection device 7 are provided.

  The beam generator 4 includes an ion source 9, a front stage accelerator (for example, a linear accelerator) 10 that accelerates ions from the ion source 9, and a synchrotron 11 that further accelerates the ion beam incident from the front stage accelerator 10. Have. A high-frequency acceleration cavity 12 and a high-frequency application device 13 are installed on the beam orbit of the synchrotron 11. The acceleration cavity 12 is connected to a first high-frequency power supply (not shown) that supplies high-frequency power, and the high-frequency application device 13 is connected to a second high-frequency power supply 15 via an open / close switch 14 (irradiation stop means). Yes.

  The ion beam incident on the synchrotron 11 from the pre-stage accelerator 10 is accelerated by a high-frequency electromagnetic field generated in the high-frequency acceleration cavity 12, and is increased to a set energy (for example, about 250 MeV). When the open / close switch 14 is closed and the high frequency power from the second high frequency power supply 15 is supplied to the high frequency application device 13, a high frequency electric field is generated from the high frequency application device 13 on the ion beam that circulates within the stability limit. Applied. As a result, the ion beam moves out of the stability limit and is emitted from the extraction deflector 16 to the beam transport system 5.

  An inverted U-shaped beam transport device 17 which is a part of the beam transport system 5 and an irradiation field forming device 6 connected thereto are installed in a rotating gantry 18, and around the patient 3 by the rotating gantry 18. It is designed to rotate. Thereby, irradiation with respect to the affected part 3a of the patient 3 is enabled from a plurality of directions.

  The irradiation field forming device 6 has a casing 19 attached to a rotating gantry 18. The first scatterer 20 and the second scattering are sequentially arranged in the casing 19 from the upstream side in the beam traveling direction (downward direction in FIG. 2). A body 21, a ridge filter 22, a patient collimator 23, and a patient bolus 24 are arranged. The first scatterer 20, the second scatterer 21, and the ridge filter 22 are for expanding the irradiation range (in other words, dose distribution) of the ion beam in the radial direction and the traveling direction. The bolus 24 is for shaping the ion beam irradiation range into the shape of the affected part 3a. In this embodiment, the patient collimator 23 is disposed on the upstream side of the patient bolus 24, but may be disposed on the downstream side.

  The first scatterer 20 and the second scatterer 21 expand the ion beam irradiation range in the radial direction (in other words, the direction perpendicular to the beam traveling direction). The first scatterer 20 is composed of a plate member made of a material (a substance having a large atomic number, such as lead) having a large beam scattering amount with respect to the energy loss amount of the ion beam, and the dose distribution in the radial direction of the ion beam. Is expanded to a normal distribution. In addition, the 1st scatterer 20 may be comprised, for example with a multiple types of material, and may superimpose a some plate member on the beam advancing direction, for example.

  The second scatterer 21 has, for example, a double ring structure, a disk portion 21a made of a material having a large beam scattering angle with respect to the amount of energy loss of the ion beam (a material having a large atomic number, for example, the same), The ring portion 21a is provided on the outer peripheral side of the 21a, and is made of a material having a small beam scattering angle with respect to the energy loss amount of the ion beam (a material having a small atomic number, such as a resin). Further, the thickness dimension of the disk portion 21a is relatively short and the thickness dimension of the ring portion 21b is relatively long so that the energy loss amounts of the ion beams are equal. Thereby, the dose distribution in the radial direction of the ion beam that has been expanded in a normal distribution by the first scatterer 20 is expanded uniformly. The second scatterer 21 may have a structure in which the ratio of the material is changed stepwise in the radial direction, for example, instead of the double ring structure, and the thickness dimension is smoothly changed in the radial direction, for example. It is good also as a structure.

  The ridge filter 22 is a so-called enlarged Bragg peak forming apparatus that widens the energy distribution width of the ion beam and uniformly expands the dose distribution in the depth direction (vertical direction in FIG. 2) of the affected part 3a. The ridge filter 22 has a plurality of wedge-shaped structures, and the thickness dimension through which the ion beam is transmitted differs depending on the beam incident position. Thereby, since the amount of energy loss differs depending on the beam incident position, an ion beam having a plurality of energy components is formed. As a result, when the affected part 3a is irradiated, a plurality of Bragg peaks having different depths are formed, and as a whole, a uniform dose distribution is formed in the depth direction of the affected part 3a. In this embodiment, the ridge filter 22 is used as the enlarged Bragg peak forming device, but instead of this, for example, a range modulation wheel whose thickness dimension changes stepwise in the circumferential direction may be used.

  The patient collimator 23 is constituted by a shield that shields the ion beam, and a through-hole corresponding to the shape of the affected part 3a in the lateral direction (in other words, the direction perpendicular to the beam traveling direction) is formed in the shield. . Thereby, the irradiation range of the ion beam is shaped according to the shape of the affected part 3a in the lateral direction.

  The patient bolus 24 is formed by, for example, excavating a resin block body, and the thickness dimension changes according to the beam incident position. Thereby, the beam range is adjusted for each beam incident position, and the arrival depth of the ion beam is adjusted to the depth shape of the affected part 3a.

  Here, as a major feature of the present embodiment, the patient collimator 23 and the patient bolus 24 are arranged so as to be close to each other in the beam traveling direction, and are fixed to, for example, a cylindrical support body 25. And the drive device 26 which moves this support body 25, ie, the patient collimator 23, and the patient bolus 24 as one is provided.

  The drive device 26 of the present embodiment includes a first parallel drive mechanism 27 that moves the support 25 in a first direction (left and right direction in FIG. 2) perpendicular to the beam traveling direction, and a perpendicular to the beam traveling direction and A second parallel drive mechanism (not shown) for moving the support 25 in a second direction (perpendicular to the paper surface in FIG. 2) orthogonal to the first direction, and a beam traveling direction as a rotation axis. And a rotation drive mechanism 28 for rotating the body 25.

  The first parallel drive mechanism 27 is fixed to a ball screw 29 extending in the first direction and rotatably provided around the axis, and one end (right side in FIG. 2) of the ball screw 29. The motor 30 includes a gear 30, a gear 31 a meshing with the gear 30, and a slide 32 through which a ball screw 29 is threaded. A support body 25 is provided below the slide 32 via an annular rail member 33 so as to be rotatable about the beam traveling direction as a rotation axis. When the rotational power of the motor 31 is transmitted through the gears 31a and 32 and the ball screw 29 is rotated to one side or the opposite side, the slide 32 and the support 25 are moved to one side in the axial direction of the ball screw 29 (left side in FIG. 2) or It moves to the other side (right side in FIG. 2).

  Although the details of the second parallel drive mechanism are not illustrated, for example, like the first parallel drive mechanism 27, the second parallel drive mechanism extends in the second direction (in other words, a direction orthogonal to the axial direction of the ball screw 29) and has an axial center. The ball screw is configured to be rotatable around, a motor for rotating the ball screw through a gear, a slider screwed to the ball screw, and the like. For example, the entire first parallel drive mechanism 27 (specifically, the ball screw 29 and the motor 31) is moved in a second direction perpendicular to the beam traveling direction.

  The rotational drive mechanism 28 includes a gear 34 provided on the outer peripheral side of the support 25 and a motor 35 having a gear 35 a fixed to the slide 32 of the first parallel drive mechanism 27 and meshing with the gear 34. ing. Then, the rotational power of the motor 35 is transmitted through the gears 35a and 35, so that the support 25 rotates to one side or the opposite side with the beam traveling direction as the rotation axis.

  The affected area detection device 7 receives, for example, X-ray generators 36A and 36B that respectively irradiate X-rays from two directions toward the affected area 3a of the patient 3, and X-rays irradiated to the affected area 3a. X-ray receivers 37A and 37B that respectively acquire X-ray fluoroscopic images. X-ray fluoroscopic images acquired by the X-ray receivers 37 </ b> A and 37 </ b> B are transmitted to the control system 8.

  The control system 8 includes an irradiation control device 38, a parallel drive control device 39, and a rotation drive control device 40. Note that the irradiation control device 38, the parallel drive control device 39, and the rotation drive control device 40 may not be provided individually, and the control system 8 may be configured to perform each of these functions.

  The irradiation control device 38 is provided with a memory 41. The memory 41 stores, for example, physical information of the patient 3, irradiation conditions of the ion beam (specifically, irradiation direction, irradiation range, irradiation time, etc.) and the like. Stored in advance. The irradiation control device 38 analyzes the X-ray fluoroscopic image received from the affected part detection device 7 using information stored in the memory 41. Specifically, for example, a mark (for example, a metal ball) is embedded in advance in or near the affected part 3a of the patient 3, and the positional relationship between the affected part 3a and the mark stored in advance in the memory 41 is used. The X-ray fluoroscopic image is analyzed, and the position and shape of the affected part 3a and the amount of change are calculated. Then, the patient collimator 23 is formed so as to form an optimum irradiation range (specifically, an irradiation range in which a large dose is concentrated on the affected tissue while suppressing irradiation of the normal tissue as much as possible) corresponding to the variation of the affected portion 3a. The movement direction and the movement amount of the patient bolus 24 are calculated, and the calculation results are output to the parallel drive control device 39 and the rotation drive control device 40, respectively.

  The parallel drive control device 39 generates a drive signal in accordance with the parallel movement direction and the movement amount of the patient collimator 23 and the patient bolus 24 input from the irradiation control device 38, and the motor 31 of the first parallel drive mechanism 27 and Each is output to a motor (not shown) of the second parallel drive mechanism. As a result, the positions of the patient collimator 23 and the patient bolus 24 in the plane perpendicular to the beam traveling direction are controlled.

  The rotation drive control device 40 generates a drive signal according to the rotation direction and rotation angle of the patient collimator 23 and the patient bolus 24 input from the irradiation control device 38 and outputs the drive signal to the motor 35 of the rotation drive mechanism 28. As a result, the rotational positions of the patient collimator 23 and the patient bolus 24 are controlled.

  Further, the irradiation control device 38 may not be able to obtain an optimal irradiation range because the variation of the affected area 3a and a predetermined setting range stored in advance in the memory 41 (specifically, for example, the variation of the affected area 3a is too large). If the fluctuation of the affected area 3a deviates from the predetermined setting range, a stop signal is output and the open / close switch 14 is opened. Thereby, the power supply to the high-frequency applying device 13 is cut off, the beam emission from the cyclotron 11 to the beam transport system 5 is stopped, and the beam irradiation to the affected part 3a is stopped.

  In the above description, the affected area detection device 7 constitutes an affected area detection unit that detects a change in the affected area described in the claims. The control system 8 constitutes control means for driving and controlling the drive device of the irradiation field forming device according to the detection result of the affected area detection means, and the control system 8 and the open / close switch 14 include the affected area detected by the affected area detection means. An irradiation stopping means is configured to stop the irradiation of radiation when the fluctuation deviates from a predetermined setting range.

  Next, the operation of the particle beam therapy system 1 according to this embodiment will be described. FIG. 3 is a schematic diagram for explaining an example of the operation of the irradiation field forming apparatus 6.

  First, the treatment bed 2 is moved so that the affected area 3a of the patient 3 in the initial state is aligned with the beam axis of the irradiation field forming device 6 (see FIG. 3A). For example, when an operator inputs a treatment start signal from an operation panel (not shown), the open / close switch 14 is closed and an ion beam is emitted from the synchrotron 11 to the beam transport system 5. The ion beam that has reached the irradiation field forming device 6 through the beam transport system 5 passes through the first scatterer 20, the second scatterer 21, the ridge filter 22, the patient collimator 23, and the patient bolus 24, thereby causing the affected part 3 a. It is formed into a shape and irradiated.

  At the same time, an X-ray fluoroscopic image of the affected area 3 a is acquired by the affected area detection device 6 and is output to the irradiation control apparatus 38. The irradiation control device 38 analyzes the X-ray fluoroscopic image using information stored in advance in the memory 41, and calculates the position and shape of the affected part 3a and the amount of change thereof. Then, the movement direction and the movement amount of the patient collimator 23 and the patient bolus 24 are calculated so as to form an optimal irradiation range corresponding to the variation of the affected part 3a, and the calculation results are calculated by the parallel drive control device 39 and the rotation drive control. Output to the device 40 respectively.

  For example, as shown in FIG. 3B, when the affected part 3a is translated in the lateral direction (left side in FIG. 3B), the movement direction of the patient collimator 23 and the patient bolus 24 calculated by the irradiation control device 39 and An information signal including the amount of movement is input to the parallel drive control device 39, and the parallel drive control device 39 outputs a drive signal to the motor 31 of the first parallel drive mechanism 27. Then, the motor 31 is driven to rotate the ball screw 29, and the patient collimator 23 and the patient bolus 24 move in a first direction perpendicular to the beam traveling direction. As a result, the irradiation range of the ion beam can be translated in the lateral direction, and can be matched with the affected part 3a that fluctuates.

  For example, when the affected part 3a rotates and moves in the lateral direction, an information signal including the rotation direction and rotation angle of the patient collimator 23 and the patient bolus 24 calculated by the irradiation control device 38 is input to the rotation drive control device 40 and rotated. The drive control device 40 outputs a drive signal to the motor 35 of the rotation drive mechanism 28. Then, the motor 35 is driven, and the patient collimator 23 and the patient bolus 24 rotate with the beam traveling direction as the rotation axis. Thereby, the irradiation range of the ion beam can be rotated and matched with the affected part 3a which fluctuates.

  As described above, in the present embodiment, the irradiation range of the ion beam can be controlled following the variation of the affected part 3a, and thereby the irradiation accuracy can be increased. In addition, by making the irradiation range of the ion beam follow the fluctuation of the affected part 3a, continuous irradiation can be performed while improving the irradiation accuracy, and the treatment time can be shortened.

  In this embodiment, when the variation of the affected part 3a detected by the affected part detection device 7 is out of a predetermined setting range, the irradiation control device 38 outputs a stop signal to close the open / close switch 14 to the affected part 3a. Stop the beam irradiation. Thereby, irradiation accuracy can further be improved.

  In the above-described embodiment, the diseased part detection device 7 that acquires an X-ray fluoroscopic image is described as an example of the diseased part detection unit that detects a change in the diseased part 3a. However, the present invention is not limited thereto. That is, for example, a method of applying an ultrasonic wave to the affected part 3a and measuring a reflected wave thereof, a method of introducing a positron emission source to the affected part 3a and measuring an annihilation gamma ray, a living tissue moving in cooperation with the affected part 3a (for example, bone, diaphragm, A method of measuring the position of the chest, skin, etc.) and using the positional relationship between the affected part 13a and the biological tissue stored in advance in the memory 41 may be used. Alternatively, for example, a method may be used in which the patient 3 breathes in accordance with a signal simulating a breathing pattern and is obtained from the relationship between the breathing phase of the patient 3 stored in the memory 41 in advance and the variation of the affected part 3a. In these cases, the same effect as described above can be obtained.

  In the above-described embodiment, the drive device 26 has been described by taking as an example a configuration including the parallel drive mechanism 27 and the rotary drive mechanism 28 that move the patient collimator 23 and the patient bolus 24 together, but the present invention is not limited thereto. Absent. That is, for example, a configuration including a drive mechanism for moving the patient collimator 23 and the patient bolus 24 separately from each other may be provided, and such a modification will be described with reference to FIGS. 4 and 5.

  FIG. 4 is a schematic diagram illustrating the detailed structure of the irradiation field forming apparatus according to the present modification together with related devices, and FIG. 5 is a schematic diagram for explaining an example of the operation of the irradiation field forming apparatus according to the present modification. . 4 and 5, the same reference numerals are given to the same parts as those in the above embodiment, and the description will be omitted as appropriate.

  The driving device 26 ′ of the present modification has a first collimator parallel drive mechanism 42 that moves the patient collimator 23 in a first direction (left-right direction in FIG. 4) perpendicular to the beam traveling direction (downward direction in FIG. 4). A second collimator parallel drive mechanism (not shown) that moves in a second direction perpendicular to the beam traveling direction (direction perpendicular to the paper surface in FIG. 4), and a patient collimator with the beam traveling direction as the rotation axis A collimator rotation drive mechanism 43 for rotating the head 23, a first bolus parallel drive mechanism 44 for moving the patient bolus 24 in a first direction perpendicular to the beam traveling direction, and a second direction perpendicular to the beam traveling direction. And a second bolus parallel drive mechanism (not shown) for moving the patient bolus, and a bolus rotation drive mechanism 45 for rotating the patient bolus 24 about the beam traveling direction as a rotation axis.

  The control system 8 ′ of the present modification includes the irradiation control device 38, the collimator parallel drive control device 46, the collimator rotation drive control device 47, the bolus parallel drive control device 48, and the bolus rotation drive control device 49. Note that the irradiation control device 38, the collimator parallel drive control device 46, the collimator rotation drive control device 47, the bolus parallel drive control device 48, and the bolus rotation drive control device 49 are not provided individually, and the control system 8 provides these functions. You may comprise so that it may exhibit.

  The irradiation control device 38 analyzes the X-ray fluoroscopic image received from the affected area detection device 7 using information stored in the memory 41, and calculates the position and shape of the affected area 3a and the amount of change thereof. Then, the movement direction and the movement amount of the patient collimator 23 and the patient bolus 24 are respectively calculated so as to form an optimal irradiation range corresponding to the variation of the affected part 3a, and the calculation results are calculated as a collimator parallel drive control device 46, a collimator. It outputs to the rotation drive control device 47, the bolus parallel drive control device 48, and the bolus rotation drive control device 49, respectively.

  For example, when the affected part 3a is translated laterally from the initial state (see FIG. 5A) (see FIG. 5B), the irradiation control device 39 determines the beam incident point of the irradiation field forming device 6 and the affected part 3a. The parallel movement direction and the movement amount of the patient collimator 23 and the patient bolus 24 are calculated so that the patient collimator 23 and the patient bolus 24 are arranged on a straight line connecting the two. Then, an information signal including the parallel movement direction and movement amount of the patient collimator 23 is output to the collimator parallel drive control device 46, and the collimator parallel drive control device 46 outputs a drive signal to the motor of the first collimator parallel drive mechanism 42. Then, the patient collimator 23 is moved in a first direction perpendicular to the beam traveling direction. Further, an information signal including the parallel movement direction and the movement amount of the patient bolus 24 is output to the bolus parallel drive control device 48, and the bolus parallel drive control device 48 outputs a drive signal to the motor of the first bolus parallel drive mechanism 44. Then, the patient bolus 23 is moved in a first direction perpendicular to the beam traveling direction. As a result, the irradiation range of the ion beam can be translated in the horizontal direction, and can be matched with the affected part 3a that fluctuates.

  For example, when the affected part 3a is rotated in the horizontal direction, an information signal including the rotation direction and rotation angle of the patient collimator 23 and the patient bolus 24 calculated by the irradiation control device 38 is output from the collimator rotation drive control device 47 and the bolus rotation drive control. Each is output to the device 49. The collimator rotation drive control device 47 outputs a drive signal to the motor of the collimator rotation drive mechanism 43 to rotate the patient collimator 23 with the beam traveling direction as the rotation axis, and the bolus rotation drive control device 49 is a bolus rotation drive mechanism 45. A drive signal is output to the motor and the patient bolus 24 is rotated about the beam traveling direction as a rotation axis. As a result, the irradiation range of the ion beam can be rotated and matched with the affected affected part 3a.

  Also in the present modified example configured as described above, the irradiation range of the ion beam can be controlled following the variation of the affected part 3a as in the above-described embodiment, thereby improving the irradiation accuracy.

  In the one embodiment and the modified example, the driving devices 26 and 26 ′ include a parallel driving mechanism that moves the patient collimator 23 and the patient bolus 24 in a direction perpendicular to the beam traveling direction as a single body or a separate body. The configuration provided with the rotation drive mechanism that rotates the beam traveling direction as the rotation axis has been described as an example, but is not limited thereto. That is, for example, a drive mechanism that moves the patient collimator 23 and the patient bolus 24 in the beam traveling direction as a single body or as a separate body may be provided. If the patient collimator 23 is moved to the upstream side of the beam by this driving mechanism, the irradiation range in the radial direction of the ion beam is enlarged in a similar manner. On the contrary, if the patient collimator 23 is moved to the downstream side of the beam, the radial irradiation of the ion beam is performed. It is possible to reduce the range similarly. Further, if the patient bolus 24 is moved to the upstream side of the beam, the shape of the arrival depth of the ion beam is similarly enlarged, and conversely, if the patient bolus 24 is moved to the downstream side of the beam, the shape of the arrival depth of the ion beam is similarly reduced. Is possible. Further, for example, a drive mechanism that tilts the patient collimator 23 and the patient bolus 24 as a single body or as a separate body may be provided. When the patient collimator 23 is tilted by this drive mechanism, the radial irradiation range of the ion beam on one side of the tilt direction can be reduced, and the radial irradiation range of the ion beam on the opposite side of the tilt direction can be expanded. . In addition, when the patient bolus 24 is tilted, it is possible to enlarge the shape of the ion beam arrival depth on one side of the tilt direction and reduce the shape of the ion beam reach depth on the opposite side of the tilt direction. In these modified examples, the same effect as described above can be obtained.

It is the schematic showing the whole structure of the particle beam therapy apparatus which is one Embodiment of this invention. It is the schematic showing the detailed structure of the irradiation field forming apparatus with which the particle beam therapy apparatus which is one Embodiment of this invention is equipped with a related apparatus. It is the schematic for demonstrating an example of operation | movement of the irradiation field formation apparatus in one Embodiment of this invention. It is the schematic showing the detailed structure of the irradiation field forming apparatus which is one modification of this invention with a related apparatus. It is the schematic for demonstrating an example of operation | movement of the irradiation field formation apparatus in one modification of this invention.

Explanation of symbols

1 Particle beam therapy system (radiation therapy system)
3 Patient 3a Affected part 4 Beam generator (radiation generator)
6 Irradiation field forming device 7 affected area detection device (affected area detection means)
8 Control system (control means, irradiation stop means)
14 Open / close switch (irradiation stop means)
23 patient collimator 24 patient bolus 26 drive device 27 first parallel drive mechanism 28 rotation drive mechanism 42 first collimator parallel drive mechanism 43 collimator rotation drive mechanism 44 first bolus parallel drive mechanism 45 bolus rotation drive mechanism

Claims (6)

In a radiotherapy device that irradiates the affected area of a patient,
A radiation generator;
An irradiation field forming device that includes a collimator and a driving device that moves the collimator, and irradiates the radiation from the radiation generation device in the form of an affected area; and
An affected area detecting means for detecting a change in the affected area;
A radiotherapy apparatus comprising: a control unit that drives and controls a driving device of the irradiation field forming device according to a detection result of the affected part detection unit. In a radiotherapy device that irradiates the affected area of a patient,
A radiation generator;
A collimator, a bolus, a driving device that moves the collimator and the bolus, and an irradiation field forming device that forms and irradiates the radiation from the radiation generating device in the shape of the affected area; and
An affected area detecting means for detecting a change in the affected area;
A radiotherapy apparatus comprising: a control unit that drives and controls a driving device of the irradiation field forming device according to a detection result of the affected part detection unit.   The radiotherapy apparatus according to claim 2, wherein the driving device of the irradiation field forming device has a driving mechanism that moves the collimator and the bolus as a unit.   The radiotherapy apparatus according to any one of claims 1 to 3, wherein the driving device of the irradiation field forming device has a parallel driving mechanism that moves the collimator and / or the bolus in a direction perpendicular to a traveling direction of the radiation.   4. The radiotherapy apparatus according to claim 1, wherein the driving device of the irradiation field forming device includes a rotation driving mechanism that rotates the collimator and / or the bolus with a traveling direction of radiation as a rotation axis.   The radiotherapy apparatus according to any one of claims 1 to 5, further comprising irradiation stopping means for stopping irradiation of radiation when a change in the affected area detected by the affected area detection means deviates from a predetermined setting range.

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