JP2019150254A - Charged particle beam treatment device and operation method of the charged particle beam treatment device - Google Patents

Abstract

To provide a charged particle beam treatment device that improves an operation efficiency of a facility, and an operation method of the charged particle beam treatment device.SOLUTION: A charged particle beam treatment device 1 includes: a treatment table 4 on which a patient 15 is placed; an irradiation unit 2 for irradiating a charged particle beam B to the patient 15 on the treatment table 4; a control unit 7 for controlling the irradiation unit 2; and an X-ray CT device 40 for measuring a position of a tumor 14 of the patient 15 on the treatment table 4 before the irradiation of the charged particle beam B is started. The control unit 7 controls the irradiation unit 2 so as to correct a scheduled irradiation position based on a treatment plan map on the basis of a deviation between an actually measured position of the tumor 14 acquired by the X-ray CT device 40 before the irradiation of the charged particle beam B is started and an assumed position of the tumor 14 by the treatment plan map created beforehand, and to irradiate the charged particle beam B to the scheduled irradiation position after the correction.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a charged particle beam therapy system and a method for operating the charged particle beam therapy system.

  Conventionally, charged particle beam therapy described in Patent Document 1 below is known as a technique in such a field. In this type of charged particle beam therapy, it is necessary to place the affected part of the patient at an accurate position in accordance with a treatment plan prepared in advance. For this reason, before starting the irradiation of the charged particle beam, the patient is placed on the treatment table, the position of the affected part is confirmed by DR (digital radiography) or CBCT (cone beam CT), and the treatment table is moved. The operation was repeated until the error was less than the tolerance, and the patient was positioned with high accuracy.

Japanese Unexamined Patent Publication No. 2016-152992

  However, according to the above-described method, the repeated operation of confirming the position of the affected area and moving the treatment table may be performed many times. For this reason, it takes time to position the patient, and the entire treatment time becomes long, so that the operating rate of the facility is lowered. In view of such problems, an object of the present invention is to provide a charged particle beam therapy system and a method for operating the charged particle beam therapy system that improve the operating efficiency of the facility.

  A charged particle beam therapy system according to the present invention includes a treatment table on which a patient is placed, an irradiation unit that irradiates the patient on the treatment table with a charged particle beam, an irradiation control unit that controls the irradiation unit, and a charged particle beam. A position measuring unit that measures the position of the affected part of the patient on the treatment table before the start of irradiation, the irradiation control unit, the actual position of the affected part obtained by the position measuring unit before the start of charged particle beam irradiation, The irradiation unit corrects the irradiation planned position based on the treatment plan information based on the deviation from the estimated position of the affected part based on the treatment plan information created in advance, and irradiates the charged particle beam to the irradiation planned position after the correction. To control.

  According to this charged particle beam treatment apparatus, the charged particle beam is not irradiated as it is to the assumed position of the affected part based on the prior treatment plan information, but according to the actually measured position of the affected part obtained by the position measuring unit. Since the planned irradiation position is corrected, the charged particle beam can be irradiated in accordance with the actual position of the affected part. Since such correction of the planned irradiation position is performed, extremely high positioning accuracy is not required for positioning the affected part in the preceding stage. Accordingly, the time required for positioning the affected area is shortened, and the entire treatment time including the positioning work is shortened. As a result, the operation efficiency of the charged particle beam therapy system and the facility including the same is improved.

  The irradiation control unit corrects the planned irradiation position with a correction amount corresponding to the amount of shift in the translation direction and the amount of shift in the rotation direction between the measured position and the assumed position in a plane orthogonal to the irradiation direction of the charged particle beam. It may be.

  The irradiation control unit further corrects the scanning path of the charged particle beam based on the treatment plan information based on the deviation between the actual measurement position and the assumed position, and the charged particle beam is corrected to the corrected irradiation planned position by the corrected scanning path. You may make it control an irradiation part so that may be irradiated.

  An operation method of the charged particle beam therapy system of the present invention includes a treatment table on which a patient is placed, an irradiation unit that irradiates a charged particle beam toward the patient on the treatment table, an irradiation control unit that controls the irradiation unit, A charged particle beam therapy system operating method comprising: a position measuring unit that measures a position of an affected part of a patient on a treatment table before starting irradiation of a charged particle beam, wherein the irradiation control unit starts irradiation of the charged particle beam Planned irradiation position correction step of correcting the planned irradiation position based on the treatment plan information based on the difference between the actual measurement position of the affected part obtained by the position measurement unit in advance and the assumed position of the affected part based on the treatment plan information created in advance And an irradiation control step of controlling the irradiation unit so that the charged particle beam is irradiated to the irradiation planned position corrected by the irradiation planned position correcting step.

  ADVANTAGE OF THE INVENTION According to this invention, the operating method of the charged particle beam therapy apparatus and charged particle beam therapy apparatus which improve the operating efficiency of a plant | facility can be provided.

It is a figure which shows the charged particle beam therapy apparatus which concerns on embodiment. It is a figure which expands and shows the irradiation part etc. of the charged particle beam therapy apparatus which concerns on embodiment. It is a figure containing the X-ray CT apparatus of the charged particle beam therapy apparatus which concerns on embodiment. It is a flowchart which shows the procedure of the charged particle beam therapy by a charged particle beam therapy apparatus. (A) shows the estimated tumor position of the treatment plan map, and (b) is a diagram showing the actual measured position of the tumor by the X-ray CT apparatus.

  Hereinafter, a charged particle beam therapy system according to an embodiment of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 1, a charged particle beam therapy apparatus 1 according to an embodiment of the present invention is an apparatus used for cancer treatment or the like by radiation therapy, and charged particles generated by an ion source (not shown). An accelerator 3 that accelerates and emits a charged particle beam, an irradiation unit 2 that irradiates the irradiated body with the charged particle beam, and a beam transport line 21 that transports the charged particle beam emitted from the accelerator 3 to the irradiation unit 2. It is equipped with. The irradiation unit 2 is attached to a rotating gantry 5 provided so as to surround the treatment table 4. The irradiation unit 2 can be rotated around the treatment table 4 by a rotating gantry 5. On the treatment table 4, a patient 15 as a target of charged particle beam therapy is placed.

  FIG. 2 is a schematic configuration diagram of the vicinity of the irradiation unit 2 of the charged particle beam therapy system of FIG. In the following description, the terms “X-axis direction”, “Y-axis direction”, and “Z-axis direction” will be used. The “Z-axis direction” is a direction in which the base axis AX of the charged particle beam B extends, and is a depth direction of irradiation of the charged particle beam B. The “base axis AX” is an irradiation axis of the charged particle beam B when it is not deflected by a scanning electromagnet 6 described later. FIG. 2 shows a state in which the charged particle beam B is irradiated along the base axis AX. The “X-axis direction” is one direction in a plane orthogonal to the Z-axis direction. The “Y-axis direction” is a direction orthogonal to the X-axis direction in a plane orthogonal to the Z-axis direction.

  First, a schematic configuration of the charged particle beam therapy apparatus 1 according to the present embodiment will be described with reference to FIG. The charged particle beam therapy apparatus 1 is an irradiation apparatus according to a scanning method. The scanning method is not particularly limited, and line scanning, raster scanning, spot scanning, or the like may be employed. As shown in FIG. 2, the charged particle beam therapy system 1 includes an accelerator 3, an irradiation unit 2, a beam transport line 21, and a control unit 7 (irradiation control unit).

  The accelerator 3 is a device that accelerates charged particles and emits a charged particle beam B having a preset energy. Examples of the accelerator 3 include a cyclotron, a synchrotron, a synchrocyclotron, a linac, and the like. In addition, when employ | adopting the cyclotron which radiate | emits the charged particle beam B of the predetermined energy as the accelerator 3, the energy of the charged particle beam sent to the irradiation part 2 is employ | adopted by employ | adopting the energy adjustment part 20 (refer FIG. 1). It is possible to adjust (decrease). Since the synchrotron can easily change the energy of the emitted charged particle beam, the energy adjusting unit 20 may be omitted when the synchrotron is used as the accelerator 3. The accelerator 3 is connected to the control unit 7 and the supplied current is controlled. The charged particle beam B generated by the accelerator 3 is transported to the irradiation nozzle 9 by the beam transport line 21. The beam transport line 21 connects the accelerator 3, the energy adjustment unit 20, and the irradiation unit 2, and transports the charged particle beam emitted from the accelerator 3 to the irradiation unit 2.

  The irradiation unit 2 irradiates the tumor (affected part) 14 in the body of the patient 15 with the charged particle beam B. The charged particle beam B is obtained by accelerating charged particles at high speed, and examples thereof include a proton beam, a heavy particle (heavy ion) beam, and an electron beam. Specifically, the irradiation unit 2 is an apparatus that irradiates the tumor 14 with a charged particle beam B emitted from an accelerator 3 that accelerates charged particles generated by an ion source (not shown) and transported by a beam transport line 21. . The irradiation unit 2 includes a scanning electromagnet 6, a quadrupole electromagnet 8, a profile monitor 11, a dose monitor 12, position monitors 13a and 13b, a multi-leaf collimator 24, and a degrader 30. The scanning electromagnet 6, the monitors 11, 12, 13 a, 13 b, the quadrupole electromagnet 8, and the degrader 30 are accommodated in the irradiation nozzle 9. Thus, the irradiation part 2 is comprised by the irradiation nozzle 9 which accommodated each main component in the container. The quadrupole electromagnet 8, the profile monitor 11, the dose monitor 12, the position monitors 13a and 13b, and the degrader 30 may be omitted.

  The scanning electromagnet 6 includes an X-axis direction scanning electromagnet 6a and a Y-axis direction scanning electromagnet 6b. The X-axis direction scanning electromagnet 6a and the Y-axis direction scanning electromagnet 6b are each composed of a pair of electromagnets, change the magnetic field between the pair of electromagnets according to the current supplied from the control unit 7, and pass between the electromagnets. The charged particle beam B is scanned. The X-axis direction scanning electromagnet 6a scans the charged particle beam B in the X-axis direction, and the Y-axis direction scanning electromagnet 6b scans the charged particle beam B in the Y-axis direction. These scanning electromagnets 6 are arranged in this order on the base axis AX and downstream of the accelerator 3 from the charged particle beam B.

  The quadrupole electromagnet 8 includes an X-axis direction quadrupole electromagnet 8a and a Y-axis direction quadrupole electromagnet 8b. The X-axis direction quadrupole electromagnet 8 a and the Y-axis direction quadrupole electromagnet 8 b converge and focus the charged particle beam B according to the current supplied from the control unit 7. The X-axis direction quadrupole electromagnet 8a converges the charged particle beam B in the X-axis direction, and the Y-axis direction quadrupole electromagnet 8b converges the charged particle beam B in the Y-axis direction. The beam size of the charged particle beam B can be changed by changing the current supplied to the quadrupole electromagnet 8 to change the aperture amount (convergence amount). The quadrupole electromagnet 8 is disposed in this order on the base axis AX and between the accelerator 3 and the scanning electromagnet 6. The beam size is the size of the charged particle beam B on the XY plane. The beam shape is the shape of the charged particle beam B on the XY plane.

  The profile monitor 11 detects the beam shape and position of the charged particle beam B for alignment at the time of initial setting. The profile monitor 11 is disposed on the base axis AX and between the quadrupole electromagnet 8 and the scanning electromagnet 6. The dose monitor 12 detects the dose of the charged particle beam B. The dose monitor 12 is disposed downstream of the scanning electromagnet 6 on the base axis AX. The position monitors 13a and 13b detect and monitor the beam shape and position of the charged particle beam B. The position monitors 13 a and 13 b are disposed on the base axis AX and downstream of the charged particle beam B from the dose monitor 12. Each monitor 11, 12, 13 a, 13 b outputs the detected detection result to the control unit 7.

  The degrader 30 finely adjusts the energy of the charged particle beam B by reducing the energy of the charged particle beam B passing therethrough. In the present embodiment, the degrader 30 is provided at the distal end portion 9 a of the irradiation nozzle 9. The tip 9a of the irradiation nozzle 9 is the end on the downstream side of the charged particle beam B.

  The multi-leaf collimator 24 defines an irradiation field 60 of the charged particle beam B in a plane direction perpendicular to the irradiation axis direction based on a signal from the control unit 7, and is a shielding unit 24a including a plurality of comb teeth. , 24b. The shielding portions 24a and 24b are disposed so as to face each other, and an opening 24c is formed between the shielding portions 24a and 24b. An irradiation field of the charged particle beam B is defined by the opening 24c. The multi-leaf collimator 24 allows the charged particle beam B to pass through the opening 24c, thereby shielding the portion of the charged particle beam B irradiated to the peripheral portion of the irradiation field. In addition, when irradiating a charged particle beam by a scanning method, the irradiation field of a charged particle beam is prescribed | regulated by the path | route to which a charged particle beam is irradiated by scanning a charged particle beam. At this time, by using the multi-leaf collimator 24 to shield the charged particle beam at the end of the irradiation field, the penumbra (cut of dose distribution) is improved.

  In addition, the multi-leaf collimator 24 can change the position and shape of the opening 24c, that is, the irradiation field, by moving the shielding portions 24a and 24b back and forth in a direction orthogonal to the Z-axis direction. Further, the multi-leaf collimator 24 is guided along the irradiation axis direction by the linear guide 28 and is movable along the Z-axis direction. The multi-leaf collimator 24 is disposed on the downstream side of the position monitor 13b.

  The control part 7 is comprised by CPU, ROM, RAM, etc., for example. The control unit 7 controls the accelerator 3, the scanning electromagnet 6, the quadrupole electromagnet 8, and the multi-leaf collimator 24 based on the detection results output from the monitors 11, 12, 13a, and 13b.

  The control unit 7 of the charged particle beam therapy apparatus 1 is connected to a treatment planning apparatus 100 that performs a treatment plan for charged particle beam therapy. The treatment planning apparatus 100 measures the tumor 14 of the patient 15 by CT or the like before the treatment, and plans a dose distribution (a dose distribution of a charged particle beam to be irradiated) at each position of the tumor 14. Specifically, the treatment planning apparatus 100 creates a treatment plan map (treatment plan information) for the tumor 14. The treatment planning apparatus 100 transmits the created treatment plan map to the control unit 7.

  When performing charged particle beam irradiation by the scanning method, the tumor 14 is virtually divided into a plurality of layers in the Z-axis direction so that the charged particle beam follows a scanning path (scanning pattern) determined in the treatment plan in one layer. Scan and irradiate. Then, after the irradiation of the charged particle beam in the one layer is completed, the charged particle beam B is irradiated in the next adjacent layer. In this way, irradiation with the charged particle beam B is performed on the entire three-dimensional tumor 14 by repeating irradiation one layer at a time for each layered region divided in the Z-axis direction.

  The treatment plan map includes information on the position of the tumor 14 that is assumed to be positioned on the treatment table 4 (hereinafter referred to as “tumor assumed position”). In addition, the treatment plan map includes information on the scanning path of the charged particle beam B with respect to the estimated tumor position. The control unit 7 reads the estimated tumor position and the scanning path determined in the treatment plan map, and in principle, uses the estimated tumor position as the planned irradiation position, and sets the charged particle beam to the planned irradiation position according to the scanning path. The irradiation unit 2 is controlled so that irradiation is performed. Therefore, in principle, if the tumor 14 of the patient 15 on the treatment table 4 is accurately positioned according to the treatment plan, the charged particle beam is scanned and irradiated at the position of the tumor 14.

  Note that the above-mentioned “tumor expected position”, “scheduled irradiation position”, and “tumor measurement position” described later are all the three-dimensional shape and three-dimensional position (X, Y, and Z axes of the tumor 14). And a position in the rotational direction around three axes of X, Y, and Z).

  Furthermore, the charged particle beam treatment apparatus 1 includes a position measurement unit that measures the position of the tumor 14 of the patient 15 on the treatment table 4 before the irradiation of the charged particle beam B is started. As such a position measurement unit, for example, an X-ray CT apparatus, DR (digital radiography), or the like is employed. In the following description, the charged particle beam therapy system 1 will be described as including the X-ray CT apparatus 40 as a position measurement unit.

  The X-ray CT apparatus 40 is a type of CT apparatus called a CBCT apparatus (cone beam CT apparatus), and is used for the purpose of accurately recognizing the position of the tumor 14 on the treatment table 4 with respect to the irradiation unit 2. Specifically, prior to the charged particle beam treatment, a tomographic image (CT image) of the patient 15 in a state set on the treatment table 4 is created using the X-ray CT apparatus 40, and the patient 15 is based on the CT image. The position of the tumor 14 is recognized.

  As shown in FIG. 3, the X-ray CT apparatus 40 includes an X-ray tube 41 that irradiates the patient 15 with X-rays. One X-ray tube 41 is installed on each side of the irradiation nozzle 9. The X-ray CT apparatus 40 includes two X-ray detectors 42 that detect X-rays from the respective X-ray tubes 41. The pair of X-ray tubes 41 and the X-ray detector 42 are arranged at positions opposite to each other across the treatment table 4. The X-ray tube 41 and the X-ray detector 42 are supported by the rotating gantry 5 and configured to be rotatable, and rotate around the treatment table 4 as a unit. X-rays are emitted from the X-ray tube 41 and X-rays passing through the patient 15 on the treatment table 4 are detected by the X-ray detector 42, and X-ray image data of the patient 15 is acquired by the X-ray detector 42. The The X-ray image data is sent to the control unit 7, and the control unit 7 executes an image reconstruction process by a predetermined calculation based on the X-ray image data, and generates a CT image inside the patient 15. The control unit 7 obtains the actual position of the tumor 14 of the patient 15 on the treatment table 4 based on this CT image.

  Prior to the start of irradiation with the charged particle beam B, the control unit 7 acquires the actual position of the tumor 14 obtained by the X-ray CT apparatus 40 (hereinafter referred to as “tumor measurement position”). In addition, the control unit 7 acquires the estimated tumor position included in the treatment plan map from the treatment plan apparatus 100. And the control part 7 calculates the shift | offset | difference of tumor actual measurement position and tumor estimated position, and correct | amends the irradiation scheduled position and scanning path | route based on a treatment plan map based on the said shift | offset | difference. After the start of irradiation of the charged particle beam B, the control unit 7 controls the irradiation unit so that the corrected irradiation planned position is irradiated with the charged particle beam through the corrected scanning path.

  Next, with reference to FIG. 4 and FIG. 5, the procedure of the charged particle beam therapy by the charged particle beam therapy system 1 including the operation of the charged particle beam therapy system 1 will be described.

(Positioning step: S101 in FIG. 4)
First, the patient 15 is placed on the treatment table 4, and the patient 15 is positioned using a positioning laser marker (not shown) of the charged particle beam therapy apparatus 1. Specifically, the treatment table 4 is moved with the goal of aligning the position of the tumor 14 of the patient 15 with the assumed tumor position determined in advance in the treatment plan map. Here, a relatively coarse positioning accuracy is allowed. For example, the positional error of the tumor 14 is allowed to about 5 mm.

(Position measurement step: S103 in FIG. 4)
After positioning the patient 15, the X-ray CT apparatus 40 is driven based on the control of the control unit 7, and a CT image inside the patient 15 is acquired. Based on this CT image, the control unit 7 recognizes the actual position of the tumor 14 (tumor measurement position P1) relative to the irradiation unit 2, as shown in FIG.

(Expected irradiation position correction step: S105 in FIG. 4)
As shown in FIG. 5A, the control unit 7 separately reads the treatment plan map of the treatment plan apparatus 100 and recognizes the estimated tumor position P0 and the scanning path Q0 included in the treatment plan map. And the control part 7 calculates the position shift | offset | difference of tumor actual measurement position P1 and tumor estimated position P0. The positional deviation calculated here is a translational deviation and a rotational deviation in a plane (XY plane) orthogonal to the irradiation direction (Z direction) of the charged particle beam B. The translational shift includes a biaxial shift including an X-direction shift and a Y-direction shift. The former is referred to as “ΔX” and the latter is referred to as “ΔY”. Further, the shift in the rotation direction is a shift in the rotation direction around the Z axis, which is referred to as “ΔΦZ”.

  Next, based on the calculated ΔX, ΔY, and ΔΦZ, the control unit 7 corrects (converts) the irradiation planned position and the scanning path with the same correction amount as that of ΔX, ΔY, and ΔΦZ. That is, as shown in FIG. 5 (b), the irradiation planned position P ′ after correction is the whole of the irradiation planned position P before correction (that is, the same position as the estimated tumor position P0 in the treatment plan map). Thus, the position is translated by + ΔX, + ΔY and rotated by + ΔΦZ. Further, the pattern of the corrected scanning path Q ′ is translated by + ΔX and + ΔY as a whole relative to the pattern of the scanning path before correction (that is, the same path as the scanning path Q0 of the treatment plan map), and + ΔΦZ It becomes a pattern that is rotated and moved only.

(Correction allowable amount determination step: S107 in FIG. 4)
Here, when the above ΔX, ΔY, and ΔΦZ exceed the correction allowable amount, the processing is restarted from the above-described coarse positioning step (S101). In the correction of the planned irradiation position and the like as described above, there are cases where the beam path after the correction has a different internal organ state (bone, cavity, etc.) at the passing position and the attenuation curve is different from the beam path before the correction. However, it is necessary to avoid such correction as described above that the state of the internal organ on the beam path changes extremely. From such a viewpoint, the allowable amount of correction as described above is set, and the allowable amounts are set such that ΔX and ΔY are about 5 mm and ΔΦZ is about several degrees.

(Irradiation control process: S109 in FIG. 4)
When the above ΔX, ΔY, and ΔΦZ do not exceed the allowable correction amount, the irradiation control process is executed. In the irradiation control step, the control unit 7 controls the irradiation unit 2 so that the charged particle beam B is irradiated to the corrected irradiation planned position P ′ through the corrected scanning path Q ′. Specifically, the control unit 7 controls the current supplied to the scanning electromagnet 6 (FIG. 2) by transmitting a drive signal to the scanning controller 6c (FIG. 2), and the charged particle beam B is converted into two axes X and Y. By scanning in the direction, the charged particle beam B is irradiated to the corrected irradiation planned position P ′ along the pattern of the corrected scanning path Q ′.

  The control unit 7 is physically configured as a computer system including, for example, a CPU, RAM, ROM, auxiliary storage device, input device such as a keyboard and a mouse, an output device such as a display, a communication module, and the like. . Then, by executing a predetermined irradiation control program in the computer system constituting the control unit 7, the position measurement step S103, the planned irradiation position correction step S105, the correction allowable amount determination step S107, and the irradiation control step S109 as described above. The charged particle beam therapy system 1 is operated so as to execute. Steps S103 to S109 as described above may be automatically advanced under the control of the control unit 7, or may be advanced in a batch according to the operation of the operator.

  The effects of the charged particle beam therapy system 1 and the operation method thereof will be described. The control unit 7 of the charged particle beam therapy system 1 executes the planned irradiation position correction step S105 and the irradiation control step S109 as described above. With these executions, the charged particle beam B is not irradiated as it is to the estimated tumor position P0 in the prior treatment plan, but the tumor 14 obtained by the X-ray CT apparatus 40 as shown in FIG. The irradiation planned position and the scanning path are corrected to P ′ and Q ′, respectively, following the actual position (tumor measurement position P1). By this correction, the charged particle beam B is irradiated in accordance with the tumor actual measurement position P1, which is the actual position of the tumor 14.

  Since the irradiation planned position and the scanning path are corrected as described above, extremely high accuracy is not required as the positioning accuracy of the tumor 14 of the patient 15 in the preceding positioning step S101. That is, in the case of the conventional charged particle beam therapy apparatus, the positioning accuracy of the tumor 14 such as a positional error of less than 1 mm is required. Therefore, after placing the patient on the treatment table, the position of the tumor 14 is determined by DR or CBCT or the like. It was necessary to repeat the operation of confirming and moving the treatment table 4 many times in some cases.

  On the other hand, according to the charged particle beam therapy system 1, the required positioning accuracy of the tumor 14 is relatively small, and it is considered that, for example, a position error of about 5 mm is allowed. Therefore, the number of trials of the positioning step S101 can be reduced. If the allowable position error is about 5 mm as described above, in most cases, it is considered that the positioning operation of the patient 15 is completed without a re-execution by one positioning step S101. Accordingly, the time for positioning the tumor 14 of the patient 15 is shortened, and the entire treatment time including the positioning work is shortened. As a result, the operation efficiency of the charged particle beam therapy system 1 and the facility including the same is improved. For example, conventionally, the irradiation time of the charged particle beam to the patient 15 is about 2 minutes, but the positioning operation of the tumor 14 takes about 5 minutes. Therefore, it is considered that the shortening of the positioning operation time greatly contributes to the shortening of the entire treatment time. Moreover, X-ray exposure of the patient 15 is also reduced by reducing the number of trials of the positioning process.

  When the patient 15 is placed on the treatment table 4 in the positioning step S101, the translational displacement (ΔZ) of the tumor 14 in the Z direction, the rotational displacement (ΔΦX) around the X axis, and the Y axis around The deviation in the rotational direction (ΔΦY) tends to be small from the beginning, and can often be ignored even if correction is not performed. However, ΔZ, ΔΦX, and ΔΦY may be corrected based on the same principle as that of ΔX, ΔY, and ΔΦZ as described above.

  The present invention can be implemented in various forms including various modifications and improvements based on the knowledge of those skilled in the art including the above-described embodiments. In addition, the following modifications may be configured using the technical matters described in the above-described embodiments. You may use combining the structure of each embodiment suitably.

  In the above-described embodiment, the irradiation to the irradiation planned position after correction is realized by scanning the scanning electromagnet 6 in the scanning method, but the present invention is not limited to this method. For example, the present invention may be applied to a broad beam irradiation method in which the irradiation field of the charged particle beam B is defined by the opening state of the multi-leaf collimator 24 (FIG. 2). In this case, in the irradiation control step S109, the position of the opening 24c of the multi-leaf collimator 24 (for example, X, Y, ΦZ position) is controlled by the control unit 7 so as to correspond to the corrected irradiation planned position P ′. May be.

  If the patient collimator is used, the position of the patient collimator may be controlled in the irradiation control step S109 instead of the control of the multi-leaf collimator 24. That is, the position of the patient collimator (for example, the X, Y, and ΦZ positions) may be controlled by the control unit 7 so as to correspond to the corrected irradiation scheduled position P ′. In this case, an actuator for moving the position of the patient collimator may be provided, and the actuator may be controlled by the control unit 7.

  Moreover, the above-described scanning control of the scanning electromagnet 6 and the control of the position of the opening 24c of the multi-leaf collimator 24 may be executed in parallel. Moreover, although the charged particle beam therapy apparatus 1 of the embodiment includes both the scanning electromagnet 6 and the multi-leaf collimator 24, it is not essential to include both of these components and may be omitted as appropriate.

  DESCRIPTION OF SYMBOLS 1 ... Charged particle beam therapy apparatus, 2 ... Irradiation part, 4 ... Treatment table, 6 ... Scanning magnet, 6c ... Scanning controller (irradiation control part), 7 ... Control part (irradiation control part), 14 ... Tumor (affected part), DESCRIPTION OF SYMBOLS 15 ... Patient, 24 ... Multi-leaf collimator (irradiation control part), 40 ... X-ray CT apparatus (position measurement part), B ... Charged particle beam.

Claims (4)

A treatment table on which the patient is placed;
An irradiation unit for irradiating a charged particle beam toward a patient on the treatment table;
An irradiation control unit for controlling the irradiation unit;
A position measuring unit that measures the position of the affected part of the patient on the treatment table before the start of irradiation of the charged particle beam,
The irradiation control unit
Based on the treatment plan information based on the difference between the measured position of the affected part obtained by the position measurement unit before the start of irradiation of the charged particle beam and the assumed position of the affected part based on the treatment plan information created in advance Correct the planned irradiation position,
A charged particle beam therapy apparatus that controls the irradiation unit such that the charged particle beam is irradiated to the irradiation planned position after correction. The irradiation control unit
The projected irradiation position is corrected with a correction amount corresponding to a translation amount shift amount and a rotation direction shift amount between the measured position and the assumed position in a plane orthogonal to the irradiation direction of the charged particle beam. Item 2. A charged particle beam therapy apparatus according to Item 1. The irradiation control unit
Based on the deviation between the measured position and the assumed position, further correct the scanning path of the charged particle beam based on the treatment plan information,
The charged particle beam therapy apparatus according to claim 1, wherein the irradiation unit is controlled so that the charged particle beam is irradiated on the corrected scanning path on the corrected irradiation planned position. A treatment table on which the patient is placed;
An irradiation unit for irradiating a charged particle beam toward a patient on the treatment table;
An irradiation control unit for controlling the irradiation unit;
A position measuring unit that measures the position of the affected area of the patient on the treatment table before the start of irradiation with the charged particle beam, and an operation method of the charged particle beam therapy apparatus comprising:
The irradiation control unit is based on a deviation between an actually measured position of the affected part obtained by the position measuring unit before the start of irradiation of the charged particle beam and an assumed position of the affected part by treatment plan information created in advance. A planned irradiation position correction step for correcting the planned irradiation position based on the treatment plan information;
An irradiation control step in which the irradiation control unit controls the irradiation unit to irradiate the charged particle beam to the irradiation planned position corrected by the planned irradiation position correction step. Actuation method.

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