JP2023063024A - Particle beam treatment device - Google Patents

Abstract

To provide a particle beam treatment device which can reduce the variations in the quality of a particle beam in a treatment in a plurality of irradiation spaces.SOLUTION: A particle beam treatment device 1 comprises a plurality of energy change units 50A, 50B which are provided in a plurality of branch paths 31A, 31B to change the energy of a particle beam. Namely, the individual energy change units 50A, 50B are provided for the irradiation spaces of a plurality of irradiation chambers 101A, 101B. In a case, on the downstream with respect to the energy change units 50A, 50B of the respective branch paths 31A, 31B, a difference in a structure related to adjustment of a transport parameter of the particle beam can be easily reduced. Therefore, adjustment in the transport parameter in each transport path 4 to the irradiation spaces of the plurality of irradiation chambers 101A, 101B becomes easy.SELECTED DRAWING: Figure 1

Description

The present invention relates to a particle beam therapy system.

As a particle beam therapy system, for example, one disclosed in Patent Document 1 is known. A particle beam therapy system includes an accelerator that accelerates particles to generate a particle beam, an irradiation device that irradiates the particle beam generated by the accelerator, and a transport path that transports the particle beam from the accelerator to the irradiation device. In the building where the particle beam therapy system is installed, one irradiation device is installed for one accelerator. The transport path thus extends from the accelerator to one irradiation chamber.

JP 2015-163229 A

Here, a building may be provided with a plurality of irradiation devices. In this case, the transport path extends from the accelerator and branches into a plurality of branch paths to transport the particle beam to a plurality of irradiation spaces. In this case, an energy changer for changing the energy of the particle beam is provided in the common route on the upstream side in the transport direction of the branched portion of the transport route. In such a configuration, it is difficult to adjust the transport parameters of the particle beam downstream of the energy changing unit, and there is a problem that the quality of the particle beam tends to vary during treatment in a plurality of irradiation spaces.

Accordingly, an object of the present invention is to provide a particle beam therapy system capable of reducing variations in the quality of particle beams in treatment in a plurality of irradiation spaces.

A particle beam therapy apparatus according to the present invention includes an accelerator that accelerates particles to generate a particle beam, a transport path that extends from the accelerator and branches into a plurality of branch paths, and is provided so that the particle beam can be transported. and a plurality of energy changing units provided in each of the branch paths to change the energy of the particle beam.

A particle beam therapy system according to the present invention has a transport path extending from an accelerator, branching into a plurality of branch paths, and provided so as to transport a particle beam. Therefore, the particle beam generated by the accelerator is irradiated in any irradiation space through any branch route of the transportation route. On the other hand, a particle beam therapy system includes a plurality of energy changing units that are provided in each of a plurality of branch paths and that change the energy of the particle beam. That is, individual energy changing units can be provided for a plurality of irradiation spaces. In this case, it becomes easier to reduce the structural difference related to the adjustment of the transport parameter of the particle beam downstream of the energy change section of each branch path. Therefore, it becomes easy to adjust the transport parameters in each transport route for a plurality of irradiation spaces. As described above, it is possible to reduce variations in particle beam quality in treatment in a plurality of irradiation spaces.

Each branch path may have substantially the same structure on the downstream side in the transport direction of the particle beam from the energy changing section. In this case, the configuration related to the adjustment of the transport parameter of the particle beam can be substantially the same downstream of the energy changing section of each branch path. Therefore, it becomes easy to adjust the transport parameters in each transport route for a plurality of irradiation spaces.

Each branch path may have an irradiation field forming device that forms an irradiation field of the particle beam with which the irradiation target is irradiated, downstream of the energy changing section in the transport direction of the particle beam. In this case, by reducing the difference in the structure of the irradiation field forming device in each irradiation space, it becomes easier to adjust the transport parameters in each transport route for a plurality of irradiation spaces.

Each branch path may have an irradiation direction changing device that changes the irradiation direction of the particle beam with which the irradiation target is irradiated, downstream of the energy changing unit in the transport direction of the particle beam. In this case, by reducing structural differences in the irradiation direction changing device in each irradiation space, adjustment of transport parameters in each transport route for a plurality of irradiation spaces is facilitated.

A selection unit may be provided in each of the plurality of branch paths and configured to select the energy of the particle beam downstream of the energy change unit in the transport direction of the particle beam. In this case, by reducing the difference in the position of the selector in each branch route, it becomes easier to adjust the transport parameter in each transport route for a plurality of irradiation spaces.

A plurality of branch paths may be provided so that the particle beam can be transported to a plurality of irradiation spaces in which the irradiation target is irradiated with the particle beam.

According to the present invention, it is possible to provide a particle beam therapy system capable of reducing variation in the quality of particle beams in treatment in a plurality of irradiation spaces.

1 is a plan view layout of a particle beam therapy system according to an embodiment of the present invention; FIG. 2 is a schematic configuration diagram of the vicinity of an irradiation unit of the particle beam therapy system of FIG. 1; FIG. FIG. 11 shows layers set for a tumor; FIG. 4 is a schematic diagram for explaining a base axis of an irradiation unit; FIG. 2 is a plan view layout of a particle beam therapy system according to a comparative example; FIG. 2 is a plan view layout of a particle beam therapy system according to a comparative example;

A preferred embodiment of a particle beam therapy system according to the present invention will be described below with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and overlapping descriptions are omitted. In this embodiment, a charged particle beam therapy system is used as the particle beam therapy system. A particle beam therapy system is applied, for example, to cancer treatment, and is a system that irradiates a tumor (irradiation target) in a patient's body with a particle beam such as a proton beam.

A schematic configuration of the particle beam therapy system of this embodiment will be described. FIG. 1 is a plan view layout of a particle beam therapy system according to an embodiment of the present invention. As shown in FIG. 1, a particle beam therapy system 1 includes an accelerator 2 that generates particle beams, and a plurality of rotatable irradiation devices that irradiate a patient 15 on a treatment table 16 with particle beams from arbitrary directions. 3 and a transport path 4 for transporting the particle beam generated by the accelerator 2 to the irradiation device 3 . Further, each device of the particle beam therapy system 1 is installed in a room of the building 100, for example.

In this embodiment, the building 100 has multiple irradiation chambers 101 for one accelerator 2 . One irradiation device 3 is provided in each irradiation chamber 101 . In the example shown in FIG. 1, two irradiation chambers 101 and two irradiation devices 3 are provided, but the number of irradiation chambers 101 and irradiation devices 3 is not particularly limited. Details of the configuration of the transportation route 4 and details of the layout of the particle beam therapy system 1 will be described later. Note that one irradiation device 3 need not be provided in one irradiation chamber 101 , and a plurality of irradiation devices 3 may be provided in one irradiation chamber 101 .

The irradiation device 3 includes an irradiation field forming device 6 and a gantry 5 (irradiation direction changing device). The irradiation field forming device 6 is a device that forms an irradiation field of particle beams with which an irradiation target is irradiated. The irradiation field forming device 6 is attached to a gantry 5 that surrounds the treatment table 16 . The irradiation field forming device 6 is rotatable around the treatment table 16 by the gantry 5 . The gantry 5 is rotatable around a rotation axis. The transport path 4 enters the gantry 5 from the rear end side of the gantry 5 . In the transport path 4, after the trajectory of the particle beam is changed to the outer peripheral side by the bending electromagnet 7, the trajectory of the particle beam is greatly bent by the bending electromagnet 8 (an example of a sextupole magnet or a bending magnet having a sextupole component). , enters the irradiation device 3 from the outer peripheral side.

A momentum analysis slit 55 is provided between the bending electromagnets 7 and 8 . The bending electromagnet 7, the momentum analysis slit 55, and the bending electromagnet 8 function as an analyzer 57 that defines momentum dispersion (defines energy spread). In addition to the momentum analysis slit 55 , a quadrupole magnet 56 may be provided between the bending electromagnets 7 and 8 .

FIG. 2 is a schematic configuration diagram of the vicinity of the irradiation section of the particle beam therapy system of FIG. In the following description, the terms "X-axis direction", "Y-axis direction", and "Z-axis direction" are used. The “X-axis direction” is the direction along the base axis AX of the irradiation device 3 and the depth direction of the particle beam B irradiation. The details of the "key axis AX" will be described later. FIG. 2 shows a state in which the particle beam B is irradiated along the base axis AX. “Y-axis direction” is one direction in a plane perpendicular to the X-axis direction. “Z-axis direction” is a direction orthogonal to the Y-axis direction in a plane orthogonal to the X-axis direction.

A detailed configuration of the particle beam therapy system 1 according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG. As the particle beam therapy apparatus 1, an irradiation apparatus related to a scanning method is exemplified, but it is not particularly limited, and a broad beam method or other irradiation methods may be employed. The scanning method is not particularly limited, and line scanning, raster scanning, spot scanning, or the like may be employed. The particle beam therapy system 1 includes an accelerator 2 , an irradiation device 3 and a transportation path 4 , as well as a controller 80 and a treatment planning device 90 . In FIG. 2, one of the plurality of irradiation devices 3 is shown.

The accelerator 2 is a device that accelerates charged particles to generate a particle beam B with a preset energy. A particle beam B generated by the accelerator 2 passes through a trajectory formed by the transportation path 4 and is guided to the irradiation device 3 . Examples of the accelerator 2 include a cyclotron, a synchrocyclotron, a linac, and the like. These are fixed energy accelerators that generate a fixed energy particle beam B. A cyclotron that emits a particle beam B with a predetermined energy is employed as the accelerator 2 in this embodiment.

The irradiation device 3 irradiates the particle beam B generated by the accelerator 2 . Specifically, as shown in FIG. 2, the irradiation device 3 irradiates a tumor (irradiation target) 14 in the body of a patient 15 with a particle beam B. As shown in FIG. The charged particles, which are the particle beam B, are obtained by accelerating charged particles at high speed, and include, for example, proton beams, heavy particle (heavy ion) beams, and electron beams. Specifically, the irradiation device 3 is a device that irradiates the tumor 14 with a particle beam B emitted from an accelerator 2 that accelerates charged particles generated by an ion source (not shown) and transported through a transport path 4 . The irradiation field forming device 6 of the irradiation device 3 includes a scanning electromagnet 10 , a duct 11 , a dose monitor 12 (an example of a monitor), a position monitor 13 (an example of a monitor), a collimator 17 and a range shifter 30 . The scanning electromagnet 10, the duct 11, the monitors 12 and 13, the collimator 17 and the range shifter 30 are housed in the irradiation nozzle 9 as a housing. In this manner, the irradiation field forming device 6 is configured by housing each main component in the irradiation nozzle 9 . In addition to the elements described above, a sextupole magnet or a bending magnet having a sextupole component and a profile monitor may be provided on the upstream side of the scanning electromagnet 10 .

The scanning electromagnet 10 includes a Y-axis direction scanning electromagnet 10a and a Z-axis direction scanning electromagnet 10b. The Y-axis direction scanning electromagnet 10a and the Z-axis direction scanning electromagnet 10b are each composed of a pair of electromagnets, and the magnetic field between the pair of electromagnets is changed according to the current supplied from the control unit 80 to pass between the electromagnets. A particle beam B is scanned. By the scanning electromagnet 10, the Y-axis direction scanning electromagnet 10a scans the particle beam B in the Y-axis direction, and the Z-axis direction scanning electromagnet 10b scans the particle beam B in the Z-axis direction. These scanning electromagnets 10 are arranged on the base axis AX and downstream of the particle beam B from the accelerator 2 in this order. The scanning electromagnet 10 scans the particle beam B so that the particle beam B is emitted along the scanning path planned in advance by the treatment planning device 90 . Note that the particle beam B may be scanned in the X direction and the Y direction by one scanning electromagnet.

The duct 11 is arranged downstream with respect to the scanning electromagnet 10 on the base axis AX. The duct 11 guides the particle beam B scanned by the scanning electromagnet 10 to the dose monitor 12 arranged downstream with respect to the duct 11 . The duct 11 has, for example, a truncated cone shape that widens from upstream to downstream of the base axis AX. The duct 11 penetrates along the base axis AX. The inside of the duct 11 is exposed to the atmosphere. That is, the duct 11 contains the atmosphere (air) inside. Atmosphere (air) includes, for example, nitrogen and oxygen. The inside of the duct 11 is exposed to the atmosphere, for example. At this time, the entire interior of the irradiation nozzle 9 may be exposed to the atmosphere, or only the interior of the duct 11 may be exposed to the atmosphere. It should be noted that the above locations may not be exposed to the atmosphere, may be filled with helium, or may be evacuated.

The dose monitor 12 is arranged downstream of the duct 11 on the base axis AX. The position monitor 13 detects and monitors the beam shape and position of the particle beam B. FIG. The position monitor 13 is arranged on the base axis AX and downstream of the particle beam B from the dose monitor 12 . Each of the monitors 12 and 13 outputs the detected detection result to the control section 80 .

The range shifter 30 reduces the energy of the passing particle beam B to shift the range of the particle beam B. In this embodiment, the range shifter 30 is provided at the tip portion 9 a of the irradiation nozzle 9 . Note that the tip 9a of the irradiation nozzle 9 is the end of the particle beam B on the downstream side.

The collimator 17 is provided at least downstream of the particle beam B from the scanning electromagnet 10, and is a member that shields part of the particle beam B and allows part of the particle beam B to pass through. Here, the collimator 17 is provided downstream of the position monitor 13 . The collimator 17 is connected to a collimator driver 18 that moves the collimator 17 .

The control unit 80 is composed of, for example, a CPU, a ROM, a RAM, and the like. This control unit 80 controls the accelerator 2 , the scanning electromagnet 10 and the collimator driving unit 18 based on the detection results output from the monitors 12 and 13 .

The controller 80 of the particle beam therapy system 1 is also connected to a treatment planning system 90 that plans treatment for particle beam therapy. The treatment planning device 90 measures the tumor 14 of the patient 15 by CT or the like before treatment and plans the dose distribution at each position of the tumor 14 . Specifically, treatment planning system 90 creates a treatment planning map for tumor 14 . The treatment planning device 90 transmits the created treatment planning map to the controller 80 . In the treatment planning map created by the treatment planning device 90, the scanning path of the particle beam B is planned.

When the particle beam B is irradiated by the scanning method, the tumor 14 is virtually divided into a plurality of layers in the X-axis direction, and one layer is scanned and irradiated with the particle beam following the scanning path determined in the treatment plan. do. Then, after the irradiation of the particle beam B on the one layer is completed, the irradiation of the particle beam B on the next adjacent layer is performed.

When performing particle beam irradiation by the scanning method, first, the particle beam B is emitted from the accelerator 2 . The emitted particle beam B is scanned by controlling the scanning electromagnet 10 so as to follow the scanning path determined in the treatment plan. As a result, the particle beam B irradiates the tumor 14 while scanning the irradiation range in one layer set in the Z-axis direction. After the irradiation of one layer is completed, the particle beam B is applied to the next layer. In this manner, the irradiation field forming device 6 can form an irradiation field in one layer.

A particle beam irradiation image of the scanning electromagnet 10 according to the control of the control unit 80 will be described with reference to FIGS. 3(a) and 3(b). FIG. 3 is a diagram showing layers set for a tumor. FIG. 3(a) shows an irradiated object virtually sliced into multiple layers in the depth direction, and FIG. 3(b) shows a scanning image of a particle beam in one layer viewed from the depth direction. each shown.

As shown in FIG. 3A, the object to be irradiated is virtually sliced into a plurality of layers in the irradiation depth direction. , layer L ₁ , layer L ₂ , . . . layer L _n−1 , layer L _n , layer L _{n + 1} , . Further, as shown in FIG. 3B, the particle beam B draws a beam trajectory along the scanning path TL, and in the case of continuous irradiation (line scanning or raster scanning), along the scanning path TL of the layer _Ln , and in the case of spot scanning, multiple irradiation spots on the layer _Ln . The particle beam B is irradiated along a scanning path TL1 extending in the Z-axis direction, slightly shifted in the Y-axis direction along a scanning path TL2, and irradiated along an adjacent scanning path TL1. Thus, the particle beam B emitted from the irradiation device 3 controlled by the controller 80 moves along the scanning path TL.

FIG. 4 is a schematic diagram for explaining the base axis of the irradiation section. The “base axis AX” of the irradiation device 3 will be described with reference to FIG. The base axis AX is a virtual reference line that serves as a reference when the irradiation device 3 irradiates the particle beam B. As shown in FIG. When the treatment planning apparatus 90 creates a scanning pattern when planning treatment, treatment planning is also performed with reference to the axis AX. For example, when setting the layers shown in FIG. 3A, each layer is a plane perpendicular to the base axis AX. Also, the position of the base axis AX is used as a reference when setting the amount of movement in the Y-axis direction and the amount of movement in the Z-axis direction. As shown in FIG. 4A, the base axis AX is orthogonal to the centerline CL of the gantry 5 and passes through the centerline CL. Axis AX passes through isocenter AC on centerline CL of gantry 5 . As shown in FIG. 4B, when the gantry 5 is rotated to rotate the irradiation device 3 around the isocenter AC, the base axis AX is positioned at the isocenter AC on the gantry 5 regardless of the position of the irradiation device 3. pass through. Note that the XYZ coordinate system is a relative coordinate system that changes depending on the orientation of the base axis AX. FIG. 4 shows the XYZ coordinate system with the base axis AX extending in the vertical direction. In addition, FIG. 1 described above shows a state in which the base axis AX extends in the horizontal direction in order to show the state of the irradiation device 3 . Therefore, FIG. 1 shows an XYZ coordinate system corresponding to this state.

Next, with reference to FIG. 1, the detailed configuration of the transportation route 4 of the particle beam therapy system 1 and the layout of the building 100 according to this embodiment will be described.

The building 100 has irradiation chambers 101A and 101B arranged in the X-axis direction. The irradiation chamber 101A is arranged on the positive side in the X-axis direction with respect to the irradiation chamber 101B. Irradiation devices 3A and 3B are arranged in the irradiation chambers 101A and 101B, respectively. At this time, the irradiation devices 3A and 3B are arranged so that the rotation axis of the gantry 5 is parallel to the Y-axis direction. Also, the front side of the gantry 5 is arranged to be the positive side in the Y-axis direction, and the rear side of the gantry 5 is arranged to be the negative side in the Y-axis direction. The building 100 also includes an accelerator room 102 adjacent to the irradiation rooms 101A and 101B on the negative side in the Y-axis direction.

The irradiation chambers 101A and 101B and the accelerator chamber 102 are provided with a wall portion 103 extending in the X-axis direction. A wall portion 104 extending in the Y-axis direction is provided on the positive side in the X-axis direction of the irradiation chamber 101A. A wall portion 106 extending in the Y-axis direction is provided on the negative side of the irradiation chamber 101A in the X-axis direction. The wall portion 106 is a partition between the irradiation chamber 101A and the irradiation chamber 101B. A wall portion 107 extending in the X-axis direction is provided on the positive side in the Y-axis direction of the irradiation chamber 101A. A wall portion 108 extending in the Y-axis direction is provided on the negative side in the X-axis direction of the irradiation chamber 101B. A wall portion 109 extending in the X-axis direction is provided on the positive side in the Y-axis direction of the irradiation chamber 101B. A wall portion 111 extending in the Y-axis direction is provided on the positive side of the accelerator chamber 102 in the X-axis direction. The wall portion 111 is provided so as to be continuous with the wall portion 104 . A wall portion 112 extending in the Y-axis direction is provided on the negative side of the accelerator chamber 102 in the X-axis direction. A wall portion 113 extending in the X-axis direction is provided on the negative side in the Y-axis direction of the accelerator chamber 102A.

Between the wall portion 104 and the wall portion 107, an entrance 121 of the irradiation chamber 101A is formed. Between the wall portion 106 and the wall portion 109, an entrance 122 of the irradiation chamber 101B is formed. Each wall of the building 100 functions as a radiation shielding wall.

The transport path 4 extends from the accelerator 2 and is provided so as to transport the particle beam. The transport path 4 extends from the accelerator 2 and branches into a plurality of branch paths 31A and 31B to transport the particle beam to a plurality of irradiation chambers 101A and 101B that irradiate the irradiation target with the particle beam. The transport path 4 has a common path 32 extending from the accelerator 2 in the X-axis direction. The branch routes 31A and 31B branch off from the common route 32 at a branched portion. A plurality of branch paths 31A and 31B are provided so as to be able to transport particle beams to a plurality of irradiation spaces where particle beams are applied to an irradiation target.

Branch path 31A extends in the X-axis direction so as to be continuous from common path 32 . The branch path 31A bends to the positive side in the Y-axis direction at a position behind the gantry 5 in the X-axis direction. The branch path 31A enters the irradiation device 3A from the rear surface of the gantry 5 via the wall portion 103 . In the irradiation device 3A, the branch path 31A extends obliquely toward the bending electromagnet 8 at the bending electromagnet 7 position. Inside the bending electromagnet 8 , the branch path 31</b>A curves like the bending electromagnet 8 and extends to the irradiation port on the downstream side of the irradiation field forming device 6 . The branch path 31B bends toward the positive side in the Y-axis direction at the branched portion of the common path 32 . The branch path 31B enters from the rear surface of the gantry 5 through the wall 103 into the irradiation device 3B. The configuration inside the irradiation device 3B of the branched route 31B is the same as that of the branched route 31A. In the following description, the terms "upstream side" and "downstream side" are used with reference to the transport direction of the particle beam.

In the accelerator chamber 102, a bending magnet 41A, a quadrupole magnet 42A, a bending magnet 43A, a quadrupole magnet 44A, and a quadrupole magnet 46A are provided in order from the upstream side to the downstream side near the curved portion of the branch path 31A. The deflection magnets 41A and 43A are electromagnets for bending the trajectory of the particle beam. The quadrupole magnets 42A, 44A, and 46A are magnets for converging the particle beam and adjusting the shape of the particle beam. Similar to the branch path 31A, a bending magnet 41B, a quadrupole magnet 42B, a bending magnet 43B, a quadrupole magnet 44B, and a quadrupole magnet 46B are provided in order from upstream to downstream near the curved portion of the branch path 31B. A plurality of quadrupole magnets 47 are provided in the linear portion of the branch path 31A on the upstream side of the bending magnet 41A. A profile monitor (not shown) and a beam stopper may be provided between the plurality of quadrupole magnets 47 . Note that these magnets may be electromagnets.

The particle beam therapy apparatus 1 includes a plurality of energy changing units 50A and 50B that are provided in each of the plurality of branch paths 31A and 31B and that change the energy of the particle beam. The energy changing sections 50A and 50B are provided downstream of the quadrupole magnet 46A in the branch paths 31A and 31B and away from the wall section 103 toward the negative side in the Y-axis direction. The energy changing units 50A and 50B are configured by, for example, degraders 51A and 51B having attenuation members that attenuate the energy of the passed particle beam. The degraders 51A and 51B can adjust the attenuation of energy by adjusting the thickness of the attenuation member. Furthermore, the energy changers 50A, 50B may include collimators 52A, 52B on the downstream side of the degraders 51A, 51B. The collimators 52A and 52B define the emittance of the beams spread by the degrader (spreading of beam positions and variations in direction), and are made of, for example, a hollow metal material and have a hollow shape or a slit shape. The collimators 52A and 52B can be provided downstream of the degraders 51A and 51B and spaced from the wall 103 toward the negative side in the Y direction.

The energy changing units 50A and 50B, the bending electromagnet 7, the quadrupole magnet 56, the momentum analysis slit 55, and the bending electromagnet 8 described above constitute a selection system (ESS: Energy Selection System) for selecting the energy of the particle beam. Thus, a separate selection system is provided for each branch path 31A, 31B. That is, a separate selection system is provided for each irradiation device 3A, 3B. The selection system for the irradiation device 3A and the selection system for the irradiation device 3B are arranged such that the relative positions of the constituent elements constituting the respective selection systems are the same, and have the same structure. In this embodiment, the selection system is composed of the energy changing units 50A and 50B, the bending electromagnet 7, the quadrupole magnet 56, the momentum analysis slit 55, and the bending electromagnet 8. The system only needs to have at least the energy changers 50A and 50B.

The respective branch paths 31A, 31B have substantially the same structure on the downstream side of the energy changers 50A, 50B. Specifically, the irradiation field forming device 6 and the gantry 5 on the downstream side of the energy changing unit 50A in the branch path 31A, and the irradiation field forming device 6 and the gantry on the downstream side of the energy changing unit 50B in the branch path 31B. 5 have the same structure as each other. That is, the irradiation field forming device 6 of the irradiation device 3A and the irradiation field forming device 6 of the irradiation device 3B have the same components arranged in the same manner. The gantry 5 of the irradiation device 3A and the gantry 5 of the irradiation device 3B have similar components arranged in a similar manner.

Next, actions and effects of the particle beam therapy system 1 according to this embodiment will be described.

First, a particle beam therapy system 201 according to a comparative example shown in FIG. 5 will be described. A particle beam therapy apparatus 201 according to a comparative example includes an accelerator 2 in an accelerator room 202 of a building 200, an irradiation device 3 that irradiates a particle beam generated by the accelerator 2, and a particle beam that is transported from the accelerator 2 to the irradiation device 3. and a transportation route 204 . In the building 200 where the particle beam therapy system 201 is installed, one irradiation device 3 is installed for one accelerator 2 . Therefore, the transportation path 204 extends from the accelerator 2 to one irradiation chamber 203 . In such a particle beam therapy system 201, the accelerator 2, the selection system 250, the transportation path 204, and the irradiation device 3 are linearly arranged. Therefore, this structure cannot be extended to a particle beam therapy system in which irradiation devices are arranged in a plurality of irradiation chambers.

Next, a particle beam therapy system 301 according to a comparative example shown in FIG. 6 will be described. This particle beam therapy system 301 has a plurality of irradiation chambers 301A, 301B and irradiation devices 3A, 3B. The transport path 304 extends from the accelerator 2 and branches into a plurality of branch paths 331A and 331B to transport particle beams to a plurality of irradiation chambers 301A and 301B. In this case, a selection system 350 including an energy changer 351 that changes the energy of the particle beam is provided in the common route 330 on the upstream side in the transport direction of the branched portion of the transport route 304 . In such a configuration, it is difficult to adjust the particle beam transport parameter downstream of the energy changer 351 . There is a problem that the quality of particle beams tends to vary in treatment between the plurality of irradiation chambers 301A and 301B.

For example, branch path 331B for irradiation chamber 301B is longer than branch path 331A for irradiation chamber 301A. Therefore, in the branch path 331B, the particle beam tends to spread downstream of the energy changer 351 . Therefore, more electromagnets and the like are provided downstream than the energy changer 351 in the transport route 304 for the irradiation chamber 301B than in the transport route 304 for the irradiation chamber 301A. Therefore, the particle beam therapy system 301 requires a transport parameter for each energy in the transport path in order to distribute the beams to the irradiation chambers 301A and 301B, but the adjustment is difficult. Here, if a large electromagnet is used to facilitate adjustment, the cost will increase. Therefore, if a small electromagnet is used to suppress the cost, the quality of the treatment beam will vary in each irradiation space.

Also, in order to shorten the treatment time and make the Bragg peak thicker, it is necessary to widen the momentum dispersion. However, in the particle beam therapy apparatus 301 according to the comparative example, since the selection system 350 needs to be provided far from the irradiation apparatuses 3A and 3B, it is difficult to shorten the treatment time.

On the other hand, the particle beam therapy apparatus 1 according to the present embodiment extends from the accelerator 2 and branches into a plurality of branch paths 31A and 31B, and a plurality of irradiation chambers 101A and 101B in which particle beam irradiation is performed on the irradiation target. It has a transport path 4 for transporting the particle beam to. Therefore, the particle beam generated by the accelerator 2 is irradiated in one of the irradiation chambers 101A and 101B via one of the branch paths 31A and 31B of the transportation path 4. FIG. On the other hand, the particle beam therapy system 1 includes a plurality of energy changing units 50A, 50B provided in each of the plurality of branch paths 31A, 31B to change the energy of the particle beam. That is, individual energy changers 50A and 50B can be provided for the plurality of irradiation chambers 101A and 101B. In this case, it becomes easier to reduce structural differences related to the adjustment of particle beam transport parameters downstream of the energy changers 50A and 50B of the respective branch paths 31A and 31B. Therefore, it becomes easy to adjust the transport parameters in each transport route 4 for the plurality of irradiation chambers 101A and 101B. As described above, in the treatment in the irradiation spaces of the plurality of irradiation chambers 101A and 101B, variations in particle beam quality can be reduced.

The respective branch paths 31A and 31B may have substantially the same structure on the downstream side in the transport direction of the particle beam from the energy changers 50A and 50B. In this case, downstream of the energy changing units 50A and 50B of the respective branch paths 31A and 31B, the configuration related to the adjustment of the particle beam transport parameters can be substantially the same. Therefore, it becomes easy to adjust the transport parameter in each transport route 4 for the irradiation space of the plurality of irradiation chambers 101A and 101B.

Each of the branch paths 31A and 31B has an irradiation field forming device 6 that forms an irradiation field of the particle beam with which the irradiation target is irradiated, downstream of the energy changing units 50A and 50B in the transport direction of the particle beam. good. In this case, by reducing the structural difference of the irradiation field forming device 6 in the irradiation space of each irradiation chamber 101A, 101B, adjustment of the transport parameter in each transport route 4 for the irradiation space of the plurality of irradiation chambers 101A, 101B becomes easier.

Each of the branch paths 31A and 31B has a gantry 5 (irradiation direction changing device) that changes the irradiation direction of the particle beam to be irradiated to the irradiation target downstream of the energy changing units 50A and 50B in the transport direction of the particle beam. You can In this case, by reducing structural differences in the gantry 5 between the irradiation chambers, it becomes easier to adjust the transport parameters in each transport route 4 for the irradiation spaces of the plurality of irradiation chambers 101A and 101B.

A selection unit 57 may be provided in each of the plurality of branch paths 31A and 31B and selects the energy of the particle beam downstream of the energy change units 50A and 50B in the transport direction of the particle beam. In this case, by reducing the difference in the position of the selector 57 in each of the branch routes 31A and 31B, it becomes easier to adjust the transport parameters in each of the transport routes 4 with respect to the irradiation spaces of the plurality of irradiation chambers 101A and 101B.

For example, the transport parameters and the position parameters of the gantry 5 employed in the particle beam therapy apparatus 201 used in the comparative example shown in FIG. 5 can be used as they are for the irradiation apparatuses 3A and 3B shown in FIG. can't. Therefore, it takes time to adjust transport parameters and position parameters. In addition, since the isocenter characteristics of the particle beams in the irradiation apparatuses 3A and 3B are different from those in the particle beam therapy apparatus 201, the patient treated by the particle beam therapy apparatus 201 in FIG. ), it is not possible to shift to the particle beam therapy system 301 in FIG. 6 from the middle, or vice versa.

On the other hand, in the irradiation devices 3A and 3B of the particle beam therapy system 1 according to this embodiment, it is possible to make the structure downstream of the energy changing units 50A and 50B substantially the same as the particle beam therapy system 201 in FIG. is. Therefore, in the irradiation devices 3A and 3B of the particle beam therapy system 1, the transport parameters and the positional parameters of the gantry 5, etc., which are used in the particle beam therapy system 201 of FIG. 5, can be used.

In addition, by providing individual energy changing units 50A and 50B for the irradiation spaces of the plurality of irradiation chambers 101A and 101B, the degree of freedom in arranging the accelerator 2 and the transportation route 4 is improved. Therefore, as shown in FIG. 1, it is possible to employ a layout in which the area of the entire building 100 is made compact while increasing the radiation shielding properties in each room.

The invention is not limited to the embodiments described above.

For example, the specific configuration of the irradiation field forming device is not limited to the above-described embodiments. Further, the irradiation method of the irradiation field forming device is not limited to the scanning method described above, and for example, a broad beam method such as a wobbler method or a double scatterer method may be employed.

Further, the specific configuration of the irradiation direction changing device is not limited to the above-described embodiments. For example, instead of a rotary device, a non-rotary device may be employed as the irradiation direction changing device.

The structure of the building 100 and the layout of each component may be changed as appropriate without departing from the gist of the present invention.

For example, the method of branching the transport route is not particularly limited, and a pattern in which a set of bending magnets distributes the particle beam to a plurality of irradiation chambers may be employed. For example, in the configuration shown in FIG. 1, there may be a branched path extending downward from the plane of the paper from the bending magnet 41B.

DESCRIPTION OF SYMBOLS 1... Particle beam therapy apparatus, 2... Accelerator, 4... Transport path, 5... Gantry (irradiation direction changing apparatus), 6... Irradiation field formation apparatus, 31A, 31B... Branch path, 32... Common path, 50A, 50B... Energy changing section, 57... selecting section, 101A, 101B... irradiation chamber.

Claims (6)

an accelerator that accelerates particles to generate a particle beam;
a transport path extending from the accelerator and branched into a plurality of branch paths, and provided so as to transport the particle beam;
and a plurality of energy changing units provided in each of the plurality of branch paths to change the energy of the particle beam. 2. The particle beam therapy system according to claim 1, wherein each of said branch paths has substantially the same structure on a downstream side of said energy changing unit in the transport direction of said particle beam. 2. The branch path according to claim 1, wherein each of said branch paths has an irradiation field forming device that forms an irradiation field of said particle beam with which an irradiation target is irradiated, on a downstream side of said energy changing unit in a transport direction of said particle beam. 3. The particle beam therapy system according to 2. Each of said branch paths has an irradiation direction changing device for changing the irradiation direction of said particle beam with which an irradiation target is irradiated, on a downstream side of said energy changing unit in the transport direction of said particle beam. The particle beam therapy system according to any one of . 5. The method according to any one of claims 1 to 4, further comprising a selection unit that is provided in each of the plurality of branch paths and that selects the energy of the particle beam downstream of the energy change unit in the transport direction of the particle beam. The particle beam therapy system according to item 1. The particle beam according to any one of claims 1 to 5, wherein the plurality of branch paths are provided so as to transport the particle beam to a plurality of irradiation spaces in which the particle beam is irradiated onto an irradiation target. therapeutic device.

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