WO2018216087A1

WO2018216087A1 - Particle beam treatment apparatus

Info

Publication number: WO2018216087A1
Application number: PCT/JP2017/019118
Authority: WO
Inventors: 慶加藤
Original assignee: 三菱電機株式会社
Priority date: 2017-05-23
Filing date: 2017-05-23
Publication date: 2018-11-29
Also published as: TW201900236A

Abstract

The purpose of the present invention is to shorten an operation time for determining the position of an affected part and achieve the improvement in throughput of particle beam treatment. A particle beam treatment apparatus (51) of the present invention is provided with: a pair of X-ray imaging apparatuses which includes two X-ray imaging apparatuses (62a, 62b) that image a patient (45) placed on a treatment table (65) from a direction perpendicular to the patient (45); and a current command generation system (10) which generates current commands (Io) of an X-directional scanning electromagnet (32) and a Y-directional scanning electromagnet (33). The present invention is characterized in that the current command generation system (10) generates the current commands (Io) for scanning an irradiation region (70a), which is planned in a treatment plan, with a charged particle beam (31), on the basis of coordinates (planned spot coordinates (Pp)) of the irradiation region (70a) planned in the treatment plan and a movement amount (Am) which corrects a displacement between a reference image (Imr), which is a reference of the irradiation region (70a) planned in the treatment plan for the patient (45), and a collation image (Imc) imaged by the pair of X-ray imaging apparatuses.

Description

Particle beam therapy system

The present invention relates to a particle beam treatment apparatus for performing treatment by irradiating an affected area such as a tumor with a particle beam.

In recent years, development and construction of cancer treatment devices (particularly referred to as particle beam treatment devices) using particle beams such as protons and heavy ions have been promoted in radiotherapy devices intended for cancer treatment. Particle beam therapy uses a device such as an accelerator to accelerate charged particles such as protons or carbon ions to several hundred mega-electron volts, and irradiates the patient with beam-shaped charged particles (particle beams) to treat tumors inside the body. This is a method of treating cancer by giving a dose to the patient. In general, when an object (including a human body) is irradiated with a particle beam accelerated by an accelerator, the three-dimensional dose distribution in the object has a characteristic that has a maximum dose peak at one point. This maximum dose peak is called the Bragg peak. The irradiation field irradiated with the particle beam is formed by irradiating the particle beam while controlling the position of the Bragg peak. As is well known, particle beam therapy using particle beams can irradiate the cancer affected area more intensively than conventional radiotherapy such as X-rays and gamma rays, that is, pinpointing according to the shape of the affected area. Can be irradiated with a particle beam and can be treated without affecting normal cells.

In particle beam therapy, it is important to irradiate the affected area such as cancer with high accuracy. For this reason, the patient is fixed using a fixture or the like so that the position does not shift with respect to the driving treatment table in the treatment room (irradiation room) during the particle beam treatment. In order to accurately position the affected area such as cancer in the radiation irradiation range, two-stage positioning is performed. As a first step, rough positioning is performed by moving the patient to the position of the treatment table during CT (Computed Tomography) imaging for treatment planning by performing settings such as rough installation of the patient using a laser pointer or the like. After that, as the second stage, when performing patient positioning using a reference image such as a DRR (Digital Reconstructed Radiograph) image generated from a CT image for treatment planning, and an image diagnostic device such as an X-ray TV device or CT device The patient's affected part is precisely positioned by translating and rotating the position of the treatment table while confirming the position of the bone and the affected part, using a collation image that is a DR (Digital Radiograph) image taken in (1).

Patent Document 1 describes a radiation therapy system in which an X-ray imaging apparatus and a therapeutic radiation apparatus are installed on a rotating device surrounding a bed that supports a patient. The radiotherapy system of Patent Document 1 is positioned roughly on the bed using markings on the body surface, etc., and then the bed is determined from the amount of misalignment between the target (affected part) of the cone beam CT image and the target of the image at the time of treatment planning It moves to precisely position the patient's target. In Patent Document 2, in a gantry-type particle beam therapy system, a patient's affected area is identified from X-ray images taken from two directions, and the patient's affected area is precisely positioned by moving the treatment table. It is described that.

Japanese Patent Laying-Open No. 2015-29793 (0024 to 0036, 0044, FIGS. 1A and 2) International Publication WO2013 / 065139A1 (Step 0023, FIG. 5)

In the method for positioning the affected area disclosed in

Patent Documents

1 and 2, the current position of the affected area is confirmed by taking an image (position confirmation process), and the affected area is aligned by translating and rotating the treatment table (position adjustment). Step), the position confirmation step is performed again after the movement, and the position confirmation step and the position adjustment step are repeated a plurality of times until the position of the affected part is matched. For this reason, the positioning method of the affected part disclosed in

Patent Documents

1 and 2 has a problem that X-ray exposure of the patient increases by performing image capturing every time the position of the affected part is finely adjusted. Further, the positioning method of the affected part disclosed in

Patent Documents

1 and 2 has a problem that the work time for positioning becomes long by repeating the fine adjustment work, and the treatment throughput decreases.

This invention solves the said subject, and aims at providing the particle beam treatment apparatus which can shorten the operation time which positions an affected part, and can improve the throughput of particle beam treatment.

A particle beam therapy system according to the present invention includes a beam generator that generates a charged particle beam and accelerates it to a predetermined energy by an accelerator, a beam transport system that transports a charged particle beam accelerated by the beam generator, and a beam transport system. A charged particle beam transported by the X-ray scanning magnet and the Y-direction scanning magnet are scanned in the X and Y directions perpendicular to the beam axis of the charged particle beam and irradiated to the patient, and mounted on the treatment table. An X-ray imaging apparatus pair having two X-ray imaging apparatuses for imaging a placed patient from orthogonal directions, and a current command generation system that generates current commands for the X-direction scanning magnet and the Y-direction scanning magnet Yes. The current command generation system is designed based on a treatment plan and a movement amount for correcting a positional deviation between a reference image serving as a reference of an irradiation region planned in a patient treatment plan and a collation image photographed by an X-ray imaging device pair. Based on the coordinates of the irradiated region, a current command for scanning the charged particle beam in the irradiation region planned in the treatment plan is generated.

The particle beam therapy system of the present invention scans a charged particle beam in a planned irradiation region based on a movement amount for correcting a positional deviation between a reference image and a collation image and coordinates of the irradiation region planned in a treatment plan. Since the current command generation system for generating the current command is provided, the work time for positioning the affected part can be shortened, and the throughput of the particle beam therapy can be improved.

It is a figure which shows the structure of the electric current command generation system of the particle beam therapy apparatus by Embodiment 1 of this invention. It is a figure which shows the structure of the irradiation spot coordinate production | generation part of FIG. 1 is a schematic configuration diagram of a particle beam therapy system according to Embodiment 1 of the present invention. It is a figure which shows the structure of the particle beam irradiation apparatus of FIG. It is a figure which shows arrangement | positioning of the X-ray imaging apparatus by Embodiment 1 of this invention. It is a figure which shows arrangement | positioning of the X-ray imaging apparatus seen from the upper side of FIG. It is a figure which shows arrangement | positioning of the X-ray imaging apparatus seen from the right side of FIG. It is a figure explaining the parameter of the treatment table by Embodiment 1 of this invention. It is a figure explaining the conventional irradiation method. It is a figure explaining the irradiation method by Embodiment 1 of this invention. It is a flowchart which shows the positioning operation | work by Embodiment 1 of this invention. It is a flowchart which shows the detail of step S004 of FIG. It is a figure which shows the hardware constitutions which implement | achieve the functional block of the positioning computer and treatment control computer of FIG. It is a figure which shows the position alignment screen of the positioning computer of FIG. It is a figure which shows the position alignment screen of the positioning computer of FIG. It is a figure which shows the other treatment table by Embodiment 1 of this invention. It is a figure which shows other arrangement | positioning of the X-ray imaging apparatus by Embodiment 1 of this invention. It is a figure which shows other arrangement | positioning of the X-ray imaging apparatus by Embodiment 1 of this invention.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a configuration of a current command generation system of a particle beam therapy system according to Embodiment 1 of the present invention, and FIG. 2 is a diagram showing a configuration of an irradiation spot coordinate generation unit in FIG. FIG. 3 is a schematic configuration diagram of the particle beam therapy apparatus according to Embodiment 1 of the present invention, and FIG. 4 is a diagram illustrating a configuration of the particle beam irradiation apparatus of FIG. FIG. 5 is a diagram showing the arrangement of the X-ray imaging apparatus according to the first embodiment of the present invention, FIG. 6 is a diagram showing the arrangement of the X-ray imaging apparatus viewed from the upper side of FIG. 5, and FIG. It is a figure which shows arrangement | positioning of the X-ray imaging apparatus seen from the right side. FIG. 8 is a diagram for explaining parameters of the treatment table according to the first embodiment of the present invention. FIG. 9 is a diagram illustrating a conventional irradiation method, and FIG. 10 is a diagram illustrating an irradiation method according to Embodiment 1 of the present invention.

First, the difference between the conventional patient positioning and irradiation method and the patient positioning and irradiation method according to Embodiment 1 of the present invention will be described with reference to FIG. 8, FIG. 9, and FIG. In the present invention, a coordinate system based on the treatment room is used. The coordinate system based on the treatment room is a coordinate system based on the treatment room defined in the international standard IEC 61217 of IEC (International Electrotechnical Commission) or a coordinate system based on this. . In FIG. 8, the patient 45 is fixed to a treatment table 65 including a top plate 66 and a driving device 67 that drives the top plate 66, and the treatment table 65 is installed on the turntable 68. The Z axis is set in a direction passing through the turntable center 69 of the turntable 68 and the isocenter If of the particle beam therapy system. The coordinate system with reference to the treatment room is Z with the isocenter If of the particle beam therapy system as the origin and the vertical upper direction as the + direction, Y with the head direction of the patient 45 in FIG. 8 as the + direction, and these Z and Y And X, which forms a right hand system. Further, ψ, φ, θ are defined with the clockwise rotation with respect to the + direction of each X, Y, Z as the + direction. The isocenter If is a reference when a charged particle beam (particle beam) is irradiated. The isocenter If is an intersection of the gantry rotation axis and the beam axis of the charged particle beam 31 (see FIG. 4) when the particle beam irradiation device 58 is mounted on the rotating gantry 82 (see FIG. 18). It is a standard. When the particle beam irradiation device 58 is not mounted on the rotating gantry 82, the isocenter If is on the beam axis and is a reference of the irradiation target determined within the adjustable range of the treatment table 65.

In the conventional patient positioning and irradiation method, as shown in the movement direction 73 of FIG. 9, the irradiation area 70b before positioning of the patient fixed to the treatment table 65 is translated and matched with the irradiation area 70a planned in the treatment plan. The top plate 66 of the treatment table 65 was moved while being rotated. After the irradiation area 70b of the patient 45 was aligned with the planned irradiation area 70a, the charged particle beam was irradiated to the position of the irradiation spot 71 along the irradiation path 72a planned in the treatment plan. The translation of the top plate 66 in the translation direction is a movement in the X direction and the Y direction. The movement of the top plate 66 in the rotational direction is movement in the ψ direction, φ direction, and θ direction.

On the other hand, in the patient positioning and irradiation method according to the first embodiment, the patient 45 fixed to the top plate 66 of the treatment table 65 is first moved to the treatment position, and the irradiation region 70b of the patient before positioning and the treatment. The amount of positional deviation from the irradiation area 70a planned in the plan is calculated. This positional deviation amount is based on the irradiation area 70a. Thereafter, each of the irradiation spots 71 in the planned irradiation area 70 a is irradiated with a charged particle beam at a position moved to the irradiation area 70 b of the patient 45 as in the movement direction 74. In FIG. 10, the irradiation spot 71 is omitted. Here, the treatment position is the position of the treatment table 65 designated in the treatment plan or the position of the treatment table 65 determined by rehearsal. In the patient positioning and irradiation method according to the first embodiment, the planned current command to the scanning magnet power source 37 for exciting the X-direction scanning magnet 32 and the Y-direction scanning magnet 33 for scanning the charged particle beam 31 is applied to the irradiation region 70a. The charged particle beam 31 is scanned and irradiated on the basis of the current command converted by the reference positional deviation amount. Since the displacement amount is used for moving the irradiation region, it can also be referred to as a movement amount. In general, the particle beam therapy apparatus cannot scan the charged particle beam 31 in the φ direction and the ψ direction, and the adjustment in the Z direction is complicated. Adjusts by driving the driving device 67 of the treatment table 65. In this manner, by irradiating the charged particle beam 31 to the position moved to the irradiation region 70b of the patient 45, the patient 45 fixed to the treatment table 65 is moved in detail in the X direction, the Y direction, and the θ direction from the treatment position. Irradiation planned in the treatment plan is performed by irradiating the charged particle beam 31 to the position of the irradiation spot 71 along the irradiation route 72b converted from the irradiation route 72a planned in the treatment plan without moving by positioning. Region 70a can be reproduced in the patient.

The patient positioning and irradiation method according to the first embodiment will be described in detail. The particle beam therapy system 51 of the first embodiment includes a beam generation device 52, a beam transport system 59, particle

beam irradiation devices

58a and 58b, a treatment table 65 (see FIG. 5) on which a patient 45 is placed, and a patient The X-ray imaging apparatus pair (refer FIG. 5) which has two

X-ray imaging apparatuses

62a and 62b which image | photograph 45 from the orthogonal direction is provided, and the electric current command generation system 10 (refer FIG. 1). The current command generation system 10 includes a positioning computer 1 and a treatment control computer 20. The beam generator 52 includes an ion source (not shown), a pre-stage accelerator 53, and a charged particle accelerator 54. The particle beam irradiation device 58b is installed in a rotating gantry (see FIG. 18). The particle beam irradiation device 58a is installed in a treatment room having no rotating gantry. The role of the beam transport system 59 is in communication between the charged particle accelerator 54 and the particle

beam irradiation devices

58a and 58b. A part of the beam transport system 59 is installed in the rotating gantry, and the part has a plurality of deflecting

electromagnets

55a, 55b, and 55c.

The charged particle beam 31, which is a particle beam such as a proton beam generated in the ion source, is accelerated by the pre-stage accelerator 53 and is incident on the charged particle accelerator 54 from the incident device 46. The charged particle accelerator 54 is, for example, a synchrotron. The charged particle beam 31 is accelerated to a predetermined energy. The charged particle beam 31 emitted from the emission device 47 of the charged particle accelerator 54 is transported to the particle

beam irradiation devices

58a and 58b through the beam transport system 59. The particle

beam irradiation devices

58 a and 58 b irradiate the affected part of the patient 45 with the charged particle beam 31. The reference numeral 58 of the particle beam irradiation apparatus is used as a whole, and 58a and 58b are used in the case of distinction.

The charged particle beam 31 generated by the beam generator 52 and accelerated to a predetermined energy is guided to the particle beam irradiation device 58 via the beam transport system 59. In FIG. 4, the particle beam irradiation apparatus 58 includes an X-direction scanning electromagnet 32 and a Y-direction scanning electromagnet 33 that scan the charged particle beam 31 in the X direction and the Y direction that are perpendicular to the charged particle beam 31, and a position monitor 34. A dose monitor 35, a dose data converter 36, a beam data processing device 41, a scanning electromagnet power source 37, and a treatment management device 38 that controls the particle beam irradiation device 58. The treatment management device 38 includes a treatment control computer 20 and a treatment control device 40. The dose data converter 36 includes a trigger generation unit 42, a spot counter 43, and an inter-spot counter 44. In FIG. 4, the traveling direction of the charged particle beam 31 is the −Z direction. The treatment control computer 20 of the treatment management device 38 is the same as the treatment control computer 20 of the current command generation system 10.

The X-direction scanning electromagnet 32 is a scanning electromagnet that scans the charged particle beam 31 in the X direction, and the Y-direction scanning electromagnet 33 is a scanning electromagnet that scans the charged particle beam 31 in the Y direction. The position monitor 34 detects beam information for calculating a passing position (center of gravity position) and a size of a beam through which the charged particle beam 31 scanned by the X direction scanning electromagnet 32 and the Y direction scanning electromagnet 33 passes. The beam data processing device 41 calculates the passing position (center of gravity position) and size of the charged particle beam 31 based on beam information composed of a plurality of analog signals detected by the position monitor 34. Further, the beam data processing device 41 generates an abnormality detection signal indicating an abnormal position or size abnormality of the charged particle beam 31 and outputs this abnormality detection signal to the treatment management device 38.

The dose monitor 35 detects the dose of the charged particle beam 31. The treatment management device 38 irradiates the charged particle beam 31 at the affected area of the patient 45 based on the treatment plan data created by the treatment planning device 30 (see FIG. 1) and the irradiation spot coordinates Pi generated by the positioning computer 1. When the dose measured by the dose monitor 35 and converted into digital data by the dose data converter 36 reaches the target dose, the charged particle beam 31 is moved to the next irradiation position. The scanning electromagnet power source 37 scans the X direction scanning electromagnet 32 and the Y direction based on a control command (current command Io) that is a control input to the X direction scanning electromagnet 32 and the Y direction scanning electromagnet 33 output from the treatment management device 38. The set current (excitation current) of the electromagnet 33 is changed.

Here, the scanning irradiation method of the particle beam irradiation device 58 is a raster scanning irradiation method in which the charged particle beam 31 is not stopped when the irradiation position of the charged particle beam 31 is changed. A method of moving between spot positions one after another is adopted. The spot counter 43 measures the irradiation dose while the beam irradiation position of the charged particle beam 31 is stopped. The spot-to-spot counter 44 measures the irradiation dose while the beam irradiation position of the charged particle beam 31 is moving. The trigger generation unit 42 generates a dose expiration signal when the dose of the charged particle beam 31 at the beam irradiation position reaches the target irradiation dose.

The

X-ray imaging apparatuses

62a and 62b for imaging the affected part of the patient 45 are arranged at positions orthogonal to each other. The X-ray imaging apparatus 62a includes an X-ray tube 63a that emits X-rays and an X-ray detector 64a that detects X-rays. The

irradiation ports

61a and 61b shown in FIG. 5 are the tip portions of the two particle beam irradiation apparatuses 58 arranged in the treatment room. FIG. 5 shows an example of a treatment room in which two

irradiation ports

61 a and 61 b are arranged and the treatment table 65 is installed on the turntable 68. The X-ray tube 63a is disposed inside the irradiation port 61a, and the X-ray tube 63b is disposed inside the irradiation port 61b. When X-ray images are taken by the

X-ray imaging devices

62a and 62b, the

X-ray imaging devices

62a and 62b are placed on the beam axis through which the charged particle beam 31 not scanned by the X-direction scanning electromagnet 32 and the Y-direction scanning electromagnet 33 passes. Is arranged. When taking an X-ray image, the X-ray X-ray emission axis 85a emitted from the X-ray tube 63a of the X-ray imaging apparatus 62a and the X-ray X-ray emitted from the X-ray tube 63b of the X-ray imaging apparatus 62b are used. The radial axes 85b are arranged so as to be orthogonal to each other. When the X-ray image is not taken as in the case where the charged particle beam 31 is irradiated, the

X-ray imaging apparatuses

62a and 62b are retracted to a position where the charged particle beam 31 is not irradiated.

The current command generation system 10 will be described. The current command generation system 10 is an X-ray image that is an alignment reference created by the treatment planning device 30 or a reference image Imr that is an X-ray image that is an alignment reference imaged during rehearsal, and a current image that is captured for alignment. Based on the collation image Imc that is an X-ray image of the patient position, a current command Io for the X-direction scanning electromagnet 32 that scans the charged particle beam 31 and the scanning electromagnet power source 37 that excites the Y-direction scanning magnet 33 is generated. The X-ray image serving as the alignment reference created by the treatment planning apparatus 30 is a DRR image generated from a treatment planning CT image, for example. The positioning computer 1 includes a collation image input unit 2 that inputs a collation image Imc, a reference image input unit 3 that inputs a reference image Imr, and a movement amount of an irradiation field (irradiation region) based on the collation image Imc and the reference image Imr. Am, that is, a movement amount calculation unit 4 that calculates a movement amount Am of the irradiation spot 71, and an irradiation spot that generates an irradiation spot coordinate Pi obtained by correcting the planned spot coordinate Pp of the treatment plan generated by the treatment planning apparatus 30 by the movement amount Am. Coordinate generation unit 5, movement amount output unit 6 that outputs movement amount Am to treatment table 65, irradiation spot coordinate output unit 7 that outputs irradiation spot coordinates Pi to treatment control computer 20, and input devices such as a keyboard and a mouse 24, an operation input unit 8 for inputting an operation signal from the input device 24, a display device 25, and a display unit 9 for displaying an alignment screen or the like on the display device 25. Obtain. The treatment control computer 20 outputs an irradiation spot coordinate input unit 21 that inputs the irradiation spot coordinate Pi, a current command generation unit 22 that generates a current command Io from the irradiation spot coordinate Pi, and outputs the current command Io to the scanning electromagnet power source 37. A current command output unit 23. The treatment control computer 20 includes an input device 24 and a display device 25 as in the positioning computer 1, but only the main part is shown in FIG.

The irradiation spot coordinate generation unit 5 includes a planned spot coordinate input unit 11 that inputs the planned spot coordinate Pp, a movement amount input unit 12 that inputs the movement amount Am, and corrects the planned spot coordinate Pp by the movement amount Am. And a coordinate conversion unit 13 that converts the coordinates Pi. The irradiation spot coordinate generation unit 5 generates a corrected irradiation spot coordinate Pi that is a coordinate for executing the irradiation of the charged particle beam 31, that is, a correction coordinate, and can also be referred to as an irradiation execution coordinate generation unit. Each of the positioning computer 1 and the treatment control computer 20 includes a processor 98 and a memory 99 shown in FIG. FIG. 13 is a diagram illustrating a hardware configuration for realizing the functional blocks of the positioning computer and the treatment control computer of FIG. Functions of the functional blocks of the positioning computer 1 and the treatment control computer 20 are realized by the processor 98 and the memory 99. Collation image input unit 2, reference image input unit 3, movement amount calculation unit 4, irradiation spot coordinate generation unit 5, movement amount output unit 6, irradiation spot coordinate output unit 7, operation input unit 8, display unit 9 of positioning computer 1 The planned spot coordinate input unit 11, the movement amount input unit 12, and the coordinate conversion unit 13 are realized when the processor 98 mounted on the positioning computer 1 executes a program stored in the memory 99. Similarly, the irradiation spot coordinate input unit 21, the current command generation unit 22, and the current command output unit 23 of the treatment control computer 20 execute a program stored in the memory 99 by the processor 98 mounted on the treatment control computer 20. Is realized. A plurality of processors 98 and a plurality of memories 99 may cooperate to execute the above function.

The operation of the current command generation system 10 will be described. FIG. 11 is a flowchart showing the positioning operation according to Embodiment 1 of the present invention, and FIG. 12 is a flowchart showing details of step S004 in FIG. 14 and 15 are diagrams showing alignment screens of the positioning computer of FIG. In step S001, the treatment table 65 is moved to the initial position P0 (initial position arranging step). The initial position P0 is a position determined as an apparatus so that the patient 45 can be easily placed on the treatment table 65. When the treatment table 65 is mounted on the turntable 68, the θ direction is controlled by the turntable 68, and the X direction, Y direction, Z direction, ψ direction, and φ direction are controlled by the driving device 67. Is done. As shown in FIG. 16, when the treatment table 65 is installed on the floor 80 without the turntable 68, the driving device 67 has six directions of X direction, Y direction, Z direction, ψ direction, φ direction, and θ direction. Control. FIG. 16 is a diagram showing another treatment table according to the first embodiment of the present invention. The position of the top plate 66 and the position of the affected part of the patient 45 are defined by six parameters of the treatment table 65. The initial position P0 is expressed as (x0, y0, z0, ψ0, φ0, θ0) using six parameters. ψ0, φ0, and θ0 are each zero. z0 is a coordinate of a position as close as possible to the floor of the treatment room or the turntable 68 so that the patient 45 can be easily placed on the top plate 66 of the treatment table 65. x0 and y0 are the positions where the patient 45 is unlikely to contact the

irradiation ports

61a and 61b, that is, the coordinates of the retracted position.

In step S002, the patient 45 is placed on the treatment table 65 and fixed (patient fixing step). More specifically, the patient 45 is fixed to the top plate 66 of the treatment table 65 by a fixing portion. In step S003, the treatment table 65 is moved to the treatment position P1 (treatment position placement step). The treatment position P1 is a treatment table position designated by the treatment plan or a treatment table position determined by rehearsal. The treatment position P1 is expressed as (x1, y1, z1, ψ1, φ1, θ1) using six parameters. In step S004, the movement amount calculation unit 4 calculates the movement amount Am (movement amount calculation step). Details of the movement amount calculation step will be described with reference to the flowchart of FIG. In step S005, the irradiation spot coordinate generation unit 5 generates irradiation spot coordinates Pi based on the movement amount Am and the planned spot coordinates Pp (irradiation spot coordinate generation step).

The irradiation spot coordinate Pi generated by the irradiation spot coordinate generation unit 5 is output to the treatment control computer 20 by the irradiation spot coordinate output unit 7. The irradiation spot coordinate input unit 21 of the treatment control computer 20 inputs the irradiation spot coordinate Pi and outputs the irradiation spot coordinate Pi to the current command generation unit 22. The current command generation unit 22 converts the irradiation spot coordinate Pi into a current command Io using a conversion method of a conventional method. Conventional conversion methods have been established, and any conversion method may be used. The current command output unit 23 outputs a current command Io to the scanning electromagnet power source 37. As described above, the scanning electromagnet power source 37 is based on the control command (current command Io) that is a control input to the X direction scanning electromagnet 32 and the Y direction scanning electromagnet 33 output from the treatment management device 38. The setting current (excitation current) of the 32 and Y direction scanning electromagnets 33 is changed, and the charged particle beam 31 is irradiated so as to form an irradiation field based on the current command Io.

Since the particle beam therapy system 51 of the first embodiment includes the current command generation system 10, the planned spot coordinates Pp of the plurality of irradiation spots 71 along the irradiation path 72a formed in the irradiation region 70a planned in the treatment plan and An irradiation spot coordinate Pi is generated based on the movement amount Am, and the charged particle beam 31 can be irradiated along the irradiation path 72b to the position of the irradiation spot coordinate Pi. The particle beam therapy system 51 according to the first embodiment plans the patient 45 fixed to the treatment table 65 from the treatment position P1 by the treatment plan without performing detailed positioning in the X, Y, and θ directions. By irradiating the charged particle beam 31 to the position of the irradiation spot 71 along the irradiation path 72b converted from the irradiation path 72a, the irradiation region 70a planned in the treatment plan can be reproduced in the patient.

The movement amount calculation process will be described with reference to FIG. In step S011, the positioning computer 1 reads the reference image Imr and displays the reference image Imr on the alignment screen 75 of the display device 25 (reference image display step). More specifically, the reference image input unit 3 inputs the reference image Imr, and displays the reference image Imr on the alignment screen 75 of the display device 25 via the display unit 9. In step S012, the collation image Imc is imaged using the

X-ray imaging devices

62a and 62b, and the collation image Imc is displayed on the alignment screen 75 of the display device 25 via the display unit 9 (collation image display step). . More specifically, the collation image input unit 2 inputs the collation image Imc, and displays the collation image Imc on the alignment screen 75 of the display device 25 via the display unit 9.

The alignment screen 75 shown in FIG. 14 is a screen on which the reference image display process and the collation image display process are completed. The collation image Imc includes a collation image 15 a photographed from the front and a collation image 15 b photographed from the side, and these two are displayed on the alignment screen 75. For example, the collation image 15a is an image photographed by the X-ray imaging apparatus 62a of FIG. 5, and the collation image 15b is an image photographed by the X-ray imaging apparatus 62b arranged orthogonal to the X-ray imaging apparatus 62a. . The reference image Imr includes a reference image 14 a generated for the front side and a reference image 14 b generated for the side surface, and these two are displayed on the alignment screen 75.

In step S013, the positioning computer 1 operates, that is, moves the position of the collation image Imc so that the reference image Imr and the collation image Imc coincide with each other according to an instruction from the operator (collation image manipulation step). First, the operator turns on the operation button 77b displayed on the alignment screen 75 with the mouse of the input device 24 or the like. The operation button 77b is an operation button for setting the alignment screen to the superimposing mode. The alignment screen in the superposition mode is the alignment screen 76 shown in FIG. The matching image 15c and the matching image 15d correspond to the matching image 15a and the matching image 15b of the matching image Imc. The image displayed by superimposing the reference image Imr and the collation image Imc on the display area of the reference image is an image obtained by subtracting the pixel values of the reference image Imr and the collation image Imc as an image. Subtraction is a well-known technique for image processing and will not be described in detail here. The superposed image of the reference image Imr and the collation image Imc that has undergone subtraction becomes an image with a lot of unevenness when the amount of deviation is large, and becomes a flat image with little unevenness when the amount of deviation is small.

On the alignment screen 76 shown in FIG. 15, the operator sets the operation amount Aop of the image with the mouse of the input device 24 using the

operation buttons

77d, 77e, 77f, 77g, 77h, 77i, 77j, and 77k. The operation input unit 8 of the positioning computer 1 inputs the operation amount Aop of the image, and the display unit 9 displays the collation image Imc that has been moved by the operation amount Aop of the image on the alignment screen 76. That is, when the operator sets the image operation amount Aop, the collation image Imc moves according to the designated image operation amount Aop. The position of the verification image Imc is the position of the verification image Imc that the operator visually changes so that the positions of the bones and organs of the reference image Imr and the verification image Imc match, that is, the verification image position P3. The collation image position P3 can be expressed as (x3, y3, z3, 0, 0, θ3) using six parameters. There are four parameters that can be manipulated as a collation image: the X direction, the Y direction, the Z direction, and the θ direction, and the ψ direction and the φ direction cannot be manipulated. For this reason, it is expressed as (x3, y3, z3, θ3) as appropriate using four parameters capable of operating the collation image position P3. In addition, the collation image position is also denoted as P3 (x3, y3, z3, θ1) by appropriately continuing P3 and parameter notation.

The operation button 77d is an operation button for setting an operation amount in the + θ direction, and the operation button 77e is an operation button for setting an operation amount in the −θ direction. The operation amount in the θ direction is displayed on the numerical display 78a. The operation button 77f is an operation button for setting an operation amount in the + Y direction, and the operation button 77g is an operation button for setting an operation amount in the -Y direction. The operation amount in the Y direction is displayed on the numerical value display 78b. The operation button 77h is an operation button for setting an operation amount in the -X direction, and the operation button 77i is an operation button for setting an operation amount in the + X direction. The operation amount in the X direction is displayed on the numerical value display 78c. The operation button 77j is an operation button for setting an operation amount in the -Z direction, and the operation button 77k is an operation button for setting an operation amount in the + Z direction. The operation amount in the Z direction is displayed on the numerical value display 78d. The operation in the Z direction corresponds to enlargement or reduction of the collation image Imc. The operation in + Z direction enlarges the collation image Imc, and the operation in −Z direction reduces the collation image Imc.

In step S014, the positioning computer 1 calculates the movement amount Am from the operation amount Aop performed on the collation image Imc, and displays this movement amount Am on the alignment screen 76 (movement amount calculation step). More specifically, the movement amount calculation unit 4 calculates the movement amount Am from the operation amount Aop, and displays this movement amount Am on the movement amount display 79 of the alignment screen 76 via the display unit 9. The movement amount Am can be expressed by a reciprocal parameter obtained by multiplying each parameter of the operation amount Aop by -1. The manipulated variable Aop can be expressed as (Δx, Δy, Δz, 0, 0, Δθ) using six parameters. In addition, the operation amount Aop is appropriately expressed as (Δx, Δy, Δz, Δθ) using four operable parameters. Further, the operation amount is also expressed as Aop (Δx, Δy, Δz, Δθ) as appropriate. The movement amount Am can be expressed as (−Δx, −Δy, −Δz, 0, 0, −Δθ) using six parameters. In addition, the moving amount Am is appropriately expressed as (−Δx, −Δy, −Δz, −Δθ) using four operable parameters. Further, the amount of movement is also expressed as Am (−Δx, −Δy, −Δz, −Δθ) as appropriate. In order to correct misalignment in the ψ direction and φ direction that cannot be operated in the verification image operation process, the movement amount (rotation angle) is changed on the operation panel (not shown) of the treatment table 65. Therefore, the movement amount Am that moves the treatment table 65 can be expressed as (−Δx, −Δy, −Δz, −Δψ, −Δφ, −Δθ). The movement amounts in the ψ direction and φ direction are the same as the four parameters that can be operated in the collation image operation process.

In step S015, the operator determines whether or not the movement amount Am is within an allowable range (operation continuation necessity determination step). In the work continuation necessity determination step, when it is determined that the movement amount Am is not within the allowable range, that is, when it is determined that continuation is necessary, the process proceeds to step S016. If it is determined in the work continuation necessity determination step that the amount of movement Am is within the allowable range, that is, if it is determined that continuation is not required, the process is terminated. In addition, the displacement in the ψ direction and φ direction that cannot be operated with respect to the collation image Imc determines whether or not the operator is subjectively within the allowable range from the degree of overlap between the reference image Imr and the collation image Imc.

In step S016, the positioning computer 1 transmits the movement amount Am (−Δx, −Δy, −Δz, none, none, −Δθ) to the treatment table 65 and the turntable 68. A command is issued to the driving device so as to move the top plate 66 and the turntable 68 by each value of the movement amount Am (treatment table moving step). Further, the displacement in the ψ direction and φ direction that cannot be operated with respect to the collation image Imc is determined by the operator subjectively determining the amount of movement (rotation angle) from the degree of overlap between the reference image Imr and the collation image Imc. The amount of movement (rotation angle) is changed on the operation panel (not shown). The validity of the rotation angles in the ψ direction and φ direction is determined by the collation image Imc that is taken after shifting.

After the execution of step S016, the process returns to step S012, the steps S012 to S015 are executed, and the movement amount calculation step is executed until it is determined in step S015 that the movement amount Am is within the allowable range. In step S012 after step S016, the normal mode alignment screen 75 which is the initial setting is changed to the superposition mode alignment screen 76, and the degree of overlap between the reference image Imr and the collation image Imc is confirmed. At this time, if it is not necessary to operate the position of the collation image Imc, steps S013 and S014 are omitted, and the work continuation necessity determination step of step S015 is executed. In the step of determining whether or not to continue the work in step S015, if it is determined that the movement amount Am is within the allowable range, that is, if it is determined that continuation is not possible, determination of the superimposed image of the reference image Imr and the matching image Imc at that time Can also be referred to as confirmation determination of the movement amount Am. Normally, even when the treatment table moving process of step S016 is executed, it is determined that the movement amount Am is within the allowable range in the work continuation necessity determination process of step S015 by executing the treatment table moving process once. The

There are operation buttons that have not yet been explained on the alignment screens 75 and 76. The operation button 77c is an operation button for ending the alignment screen. When the operator turns on with the mouse of the input device 24, the alignment screen is ended. The operation button 77a is an operation button for setting the alignment screen to the normal mode. When the operator turns on the operation button 77 a with the mouse of the input device 24 on the alignment screen 76, the normal mode alignment screen 75 shown in FIG. 14 is displayed on the display device 25.

The current command generation system 10 according to the first embodiment calculates a movement amount Am that corrects a deviation between the reference image Imr and the collation image Imc, and uses the treatment plan planned spot coordinates Pp generated by the treatment planning apparatus 30 as the movement amount Am. A control command (current command Io), which is a control input for changing the set current (excitation current) of the X-direction scanning electromagnet 32 and the Y-direction scanning electromagnet 33, is generated based on the irradiation spot coordinates Pi corrected only. The particle beam therapy system 51 of the first embodiment changes the set current (excitation current) of the X-direction scanning electromagnet 32 and the Y-direction scanning electromagnet 33 based on this control command (current command Io) to change the charged particle beam 31. Since the affected area of the patient 45 is irradiated, the irradiation spot 71 is moved along the irradiation path 72b converted from the irradiation path 72a planned in the treatment plan without moving by detailed positioning in the X direction, the Y direction, and the θ direction. The irradiation region 70a planned in the treatment plan can be reproduced in the patient 45 by irradiating the charged particle beam 31 to the position. Therefore, the particle beam therapy system 51 according to the first embodiment does not move the treatment table 65 by detailed positioning in the X direction, the Y direction, and the θ direction, thereby reducing the work time for positioning the affected part of the patient 45. And the throughput of particle beam therapy can be improved.

The example of the

X-ray imaging apparatuses

62a and 62b in the treatment room in which the two

irradiation ports

61a and 61b are arranged has been described so far. However, the

X-ray imaging apparatuses

62a and 62b are provided in the treatment room or the rotating gantry having one irradiation port. May be installed. FIG. 17 is a diagram showing another arrangement of the X-ray imaging apparatus according to Embodiment 1 of the present invention, and FIG. 18 is a diagram showing still another arrangement of the X-ray imaging apparatus according to Embodiment 1 of the present invention. . FIG. 17 is an example in which

X-ray imaging apparatuses

62a and 62b are arranged at positions orthogonal to each other in a treatment room having one irradiation port, and FIG. 18 is an X-ray imaging apparatus 62a at positions orthogonal to the rotating gantry 82. This is an example in which 62b is arranged. In FIG. 17, since there is no irradiation port in the Z direction, an X-ray tube 63 a is arranged inside the ceiling 81.

In the rotating gantry 82, a cylindrical rotating frame 83 on which the particle beam irradiation device 58 and the deflecting

electromagnets

55a, 55b, and 55c are mounted is rotatably supported by a roller 84, and the roller 84 is rotated by a driving device (not shown). It is configured to be able to rotate 360 degrees. An irradiation port 61 that is a tip portion of the particle beam irradiation apparatus 58 is disposed in a treatment space where the treatment table 65 is installed. The X-ray tube 63a is disposed inside the irradiation port 61, and the X-ray tube 63b is disposed at a position orthogonal to the gantry rotation axis including the isocenter If and the X-ray radiation axis 85a of the X-ray imaging apparatus 62a. . Since the

X-ray imaging apparatuses

62a and 62b are arranged in this way, the X-ray radiation axis 85b of the X-ray imaging apparatus 62b is orthogonal to the X-ray radiation axis 85a of the X-ray imaging apparatus 62a.

As described above, the particle beam therapy system 51 according to Embodiment 1 generates the charged particle beam 31 and accelerates it to a predetermined energy by the accelerator (charged particle accelerator 54), and the beam generator 52. A beam transport system 59 that transports the accelerated charged particle beam 31, and the charged particle beam 31 transported by the beam transport system 59 is perpendicular to the beam axis of the charged particle beam 31 by the X-direction scanning magnet 32 and the Y-direction scanning magnet 33. A particle beam irradiation device 58 that scans in the X and Y directions and irradiates the patient 45, and two

X-ray imaging devices

62a and 62b that image the patient 45 placed on the treatment table 65 from a direction orthogonal to each other. A pair of X-ray imaging devices, and a current command generation system 10 that generates a current command Io for the X-direction scanning electromagnet 32 and the Y-direction scanning electromagnet 33. That. The current command generation system 10 according to the first embodiment corrects misalignment between the reference image Imr serving as the reference of the irradiation region 70a planned in the treatment plan for the patient 45 and the collation image Imc taken by the X-ray imaging apparatus pair. Current command Io for scanning the charged particle beam 31 in the irradiation area 70a planned in the treatment plan based on the movement amount Am to be performed and the coordinates (planning spot coordinates Pp) of the irradiation area 70a planned in the treatment plan. It is characterized by generating. With this feature, the particle beam therapy system 51 according to the first embodiment does not move by detailed positioning in the X direction, the Y direction, and the θ direction, so that the work time for positioning the affected part of the patient 45 can be shortened. The throughput of particle beam therapy can be improved.

The scanning irradiation method of the particle beam irradiation apparatus 58 has been described as the raster scanning irradiation method in which the beam irradiation positions move one after another between the spot positions as in the spot scanning irradiation method. However, the scanning is performed without stopping. The present invention can also be applied to a scanning irradiation method or a spot scanning irradiation method. In the case of the raster scanning irradiation method in which scanning is performed without stopping, the charged particle beam 31 may be irradiated along the irradiation path 72b obtained by correcting the irradiation path 72a planned in the treatment plan with the movement amount Am. Further, the present invention can be combined with each other within the scope of the present invention, and each embodiment can be appropriately modified or omitted.

DESCRIPTION OF SYMBOLS 4 ... Movement amount calculation part, 5 ... Irradiation spot coordinate generation part (irradiation execution coordinate generation part), 9 ... Display part, 10 ... Current command generation system, 14a, 14b ... Reference | standard image, 15a, 15b, 15c, 15d ... Collation Image, 25 ... Display device, 31 ... Charged particle beam, 32 ... X direction scanning electromagnet, 33 ... Y direction scanning electromagnet, 45 ... Patient, 51 ... Particle beam therapy device, 52 ... Beam generator, 54 ... Charged particle accelerator ( Accelerator), 58, 58a, 58b ... Particle beam irradiation device, 59 ... Beam transport system, 62a, 62b ... X-ray imaging device, 65 ... Treatment table, 68 ... Turntable, 70a, 70b ... Irradiation area, 71 ...

Irradiation spot

75, 76 ... alignment screen, 77a, 77b, 77c, 77d, 77e, 77f, 77g, 77h, 77i, 77j, 77k ... operation buttons, 78a, 78b, 7 c, 78d ... numeric display, Am ... movement amount, Aop ... operation amount, Io ... current command, Imc ... collation image, Imr ... reference image, Pi ... irradiation spot position (corrected coordinates), Pp ... Planning spot position

Claims

Beam generator for generating charged particle beam and accelerating to predetermined energy by accelerator, beam transport system for transporting charged particle beam accelerated by said beam generator, and charged particle beam transported by said beam transport system A particle beam irradiation apparatus for irradiating a patient by scanning in the X direction and the Y direction perpendicular to the beam axis of the charged particle beam by an X direction scanning magnet and a Y direction scanning magnet, and the patient placed on a treatment table. An X-ray imaging apparatus pair having two X-ray imaging apparatuses for imaging from orthogonal directions, and a current command generation system that generates current commands for the X-direction scanning electromagnet and the Y-direction scanning electromagnet,
The current command generation system includes:
A movement amount for correcting a positional deviation between a reference image serving as a reference of an irradiation region planned in the patient treatment plan and a collation image photographed by the X-ray imaging apparatus pair;
The coordinates of the irradiation area planned in the treatment plan;
And generating the current command for scanning the charged particle beam in the irradiation region planned in the treatment plan.
The current command generation system includes:
A movement amount calculation unit that calculates the movement amount, an irradiation execution coordinate generation unit that generates correction coordinates obtained by correcting the coordinates of the irradiation region by the movement amount, and the current command based on the correction coordinates. The particle beam therapy system according to claim 1, further comprising a current command generation unit.
The current command generation system includes a display unit that displays the reference image and the collation image on the display device,
3. The particle beam therapy system according to claim 2, wherein the movement amount calculation unit generates −1 times as much the operation amount moved from the initial position of the collation image to the changed position as the movement amount.
The display unit
On the alignment screen on which the reference image and the collation image are displayed in an overlapping manner,
4. A plurality of operation buttons for moving the collation image for each movement direction, and a numerical value of an operation amount to which the collation image is moved by operating the operation button are displayed. Particle beam therapy device.
The display unit
5. The particle beam therapy system according to claim 4, wherein each time the operation button is operated, the collation image is moved by the operation amount and a numerical value of the operation amount is displayed.
6. The current command generation system generates the current command with the coordinates of the irradiation path in the irradiation region irradiated with the charged particle beam as the coordinates of the irradiation region. The particle beam therapy apparatus according to claim 1.
6. The current command generation system generates the current command by using the coordinates of an irradiation spot irradiated with the charged particle beam as coordinates of the irradiation region. The particle beam therapy apparatus according to claim 1.
The current command generation system outputs the movement amount to the treatment table and moves the treatment table when it is determined that the movement amount is not within an allowable range. The particle beam therapy apparatus of any one of Claims.
The treatment table is installed on a turntable that rotates the treatment table with respect to the beam axis of the charged particle beam,
The rotation angle about the beam axis in the position where the treatment table captures the verification image is set by the turntable after the patient is placed on the treatment table. The particle beam therapy apparatus according to any one of 1 to 8.