JP7271142B2 - Particle beam therapy system - Google Patents

Description

An embodiment of the present invention relates to a particle beam therapy system.

Conventionally, a particle beam therapy system includes an energy modulation filter for expanding the range in which the Bragg peak of the particle beam occurs in the direction of travel of the beam. By widening the Bragg peak of the particle beam with this energy modulation filter, it is possible to annihilate lesion tissue in a wide range in the depth direction with a single irradiation of the particle beam. Therefore, the number of times of particle beam irradiation can be reduced.

U.S. Patent Application Publication No. 2010/0264327

In some cases, multiple filters for energy modulation are stacked to facilitate the manufacture of individual filters. In the particle beam therapy system, the filter used may be changed in order to make the range in which the Bragg peak occurs suitable for the patient. Here, if there are a plurality of filters, there is a problem that it takes time and effort to change each filter.

The embodiments of the present invention have been made in consideration of such circumstances, and it is an object of the present invention to provide a particle beam therapy technique capable of simplifying the work of changing the energy modulation section.

A particle beam therapy system according to an embodiment of the present invention includes a first energy modulation unit arranged on a trajectory of the particle beam during irradiation of the particle beam and widening a Bragg peak of the passing particle beam; a second energy modulation section movable between a position retracted from the orbit and a position on the orbit overlapping the first energy modulation section and widening the Bragg peak, wherein the second energy modulation section The energy distribution generated when used alone does not approximate a Gaussian distribution , and the energy distribution generated by overlapping with the first energy modulation unit at a position on the orbit approximates the Gaussian distribution. have

An embodiment of the present invention provides a particle beam therapy technique capable of simplifying the work of changing the energy modulation section.

1 is a conceptual diagram showing the overall configuration of a particle beam therapy system according to a first embodiment; FIG. Sectional drawing which shows a rotating gantry. Sectional drawing which shows an irradiation port. FIG. 4 is a cross-sectional view showing the irradiation port with the opening opened. FIG. 4 is a cross-sectional view showing an irradiation port when replacing the second energy modulation unit; FIG. 5 is a plan view showing an irradiation port corresponding to FIG. 4; FIG. 6 is a plan view showing an irradiation port corresponding to FIG. 5; FIG. 4 is an enlarged perspective view showing a ridge filter as an energy modulation section; FIG. 4 is an enlarged side view showing a state in which a particle beam passes through a ridge bar; FIG. 4 is an enlarged side view showing a ridge bar; The perspective view which shows the arrangement|positioning state of the ridge filter of 2 sheets. Graph showing the relationship between relative dose and depth. Explanatory drawing which shows the slice plane set to the affected part. FIG. 4 is an explanatory diagram showing an irradiation spot that scans a slice surface; FIG. 4 is an enlarged side view showing each stepped portion of the ridge bar; The graph which shows the relationship between each step part and a Bragg peak. FIG. 5 is an explanatory diagram showing a Gaussian distribution when the first energy modulation section is used alone; Explanatory drawing which shows Gaussian distribution at the time of using a 2nd energy modulation|alteration part independently. FIG. 5 is an explanatory diagram showing a Gaussian distribution when the first energy modulation section and the second energy modulation section are used in combination; FIG. 2 is a block diagram showing the system configuration of a particle beam therapy system; 6 is a flow chart showing replacement processing of the second energy modulator. 6 is a flow chart showing replacement processing of the second energy modulator. 4 is a flowchart showing particle beam therapy processing; Sectional drawing which shows the irradiation port of the particle beam therapy apparatus of 2nd Embodiment. Sectional drawing which shows the irradiation port of the particle beam therapy apparatus of 3rd Embodiment. Sectional drawing which shows the irradiation port of the particle beam therapy apparatus of 4th Embodiment. Sectional drawing which shows the irradiation port of the particle beam therapy apparatus of 5th Embodiment. Sectional drawing which shows the irradiation port of the particle beam therapy apparatus of 6th Embodiment. Sectional drawing which shows the irradiation port of the particle beam therapy apparatus of 7th Embodiment. Sectional drawing which shows the irradiation port of the particle beam therapy apparatus of 8th Embodiment.

(First embodiment)
The present embodiment will be described below with reference to the accompanying drawings. First, the particle beam therapy system of the first embodiment will be described with reference to FIGS. 1 to 23. FIG. Reference numeral 1 in FIG. 1 denotes a particle beam therapy system. The particle beam therapy system 1 performs treatment by irradiating a beam of particles such as carbon ions to a lesion tissue (cancer) of a patient as a subject.

Radiation therapy technology using the particle beam therapy system 1 is also called heavy particle beam cancer therapy technology. With this technology, carbon ions are pinpointed at cancer lesions (affected areas), and it is possible to minimize damage to normal cells while damaging cancer lesions. Particle beams are defined as radiation heavier than electrons, and include proton beams, heavy particle beams, and the like. Heavy ions are defined as heavier than helium atoms.

Cancer treatment using heavy ion beams has a higher ability to kill cancer lesions than conventional cancer treatments using X-rays, gamma rays, and proton beams. It has the characteristic that the radiation dose peaks at cancer lesions. Therefore, the number of times of irradiation and side effects can be reduced, and the treatment period can be shortened.

FIG. 1 is a plan view schematically showing the overall configuration of a particle beam therapy system 1. FIG. FIG. 2 is a cross-sectional view of the rotating gantry 5 as viewed from the side. Note that the left side of the paper surface of FIG. 2 will be described as the front side (front side) of the particle beam therapy system 1 .

As shown in FIGS. 1 and 2, a particle beam therapy system 1 includes a beam generator 2 having an ion source that generates carbon ions, which are charged particles, and a ring-shaped beam generator 2 that accelerates the carbon ions to form a particle beam B. , a beam transport line 4 for transporting a particle beam B, and a rotating gantry 5 on which a patient P to be irradiated with the particle beam is placed.

First, carbon ions generated by the ion source are injected from the beam generator 2 into the circular accelerator 3 . The carbon ions are accelerated to about 70% of the speed of light while circling the circular accelerator 3 about one million times, and become a particle beam B. This particle beam B is then guided to a rotating gantry 5 via a beam transport line 4 .

The circular accelerator 3 and the beam transport line 4 comprise vacuum ducts D (beam pipes) inside which are evacuated. A particle beam B travels through this vacuum duct D. As shown in FIG. The circular accelerator 3 and the vacuum duct D of the beam transport line 4 are integrated to form a transport path for guiding the particle beam B to the rotating gantry 5 . That is, the vacuum duct D is a closed continuous space having a degree of vacuum sufficient to allow the particle beam B to pass through.

The circular accelerator 3 includes a high-frequency acceleration cavity 22 that accelerates carbon ions by controlling the frequencies of the magnetic field and acceleration electric field, and a bending electromagnet 23 that controls the traveling direction of the particle beam B to be circular.

The beam transport line 4 also includes a bending electromagnet 24 that is used to change the traveling direction of the particle beam B, and a control quadrupole electromagnet 25 that controls the convergence and divergence of the particle beam B. FIG.

Each of the electromagnets 23-25 is arranged so as to surround the outer circumference of the vacuum duct D. As shown in FIG. A plurality of electromagnets 23 to 25 are arranged along the direction in which the vacuum duct D extends. Note that other devices or electromagnets may be provided in the circular accelerator 3 or beam transport line 4 .

As shown in FIG. 2, the rotating gantry 5 is a large cylindrical device. The rotating gantry 5 is installed so that the rotation axis J of the cylinder is oriented horizontally. The rotary gantry 5 is rotatable around this rotary axis J. As shown in FIG.

A support roller 7 that rotatably supports the rotating gantry 5 and a drive motor 8 that rotates the rotating gantry 5 around the rotation axis J are provided below the rotating gantry 5 .

The rotating gantry 5 is supported by support rollers 7 via an end ring 9 fixed to its outer periphery. A rotational driving force of the drive motor 8 is applied to the rotating gantry 5 via the support rollers 7 and the end rings 9 .

A vacuum duct D extending from the beam transport line 4 and a bending electromagnet 6 are attached to the rotating gantry 5 . In the rotating gantry 5, the vacuum duct D is first led from the outside of the rotating gantry 5 along its rotation axis J, extends toward the cylindrical outer periphery of the rotating gantry 5, and then reaches the inner periphery of the rotating gantry 5 again. extending to the side. A bending electromagnet 6 is used to change the traveling direction of the particle beam B along the vacuum duct D. FIG.

An irradiation port 10 for irradiating the patient P with the particle beam B guided by the beam transport line 4 is provided at the end of the vacuum duct D. As shown in FIG. This irradiation port 10 is fixed to the inner peripheral surface of the rotating gantry 5 . The particle beam B is emitted from the irradiation port 10 in a direction perpendicular to the rotation axis J. As shown in FIG.

A rotating mechanism is provided in a portion of the vacuum duct D along the rotation axis J of the rotating gantry 5 so that this portion rotates as the rotating gantry 5 rotates.

As shown in FIGS. 3 and 11, a scanning electromagnet 11 is provided near the end of the vacuum duct D. As shown in FIGS. The scanning electromagnet 11 has an X deflection scanning magnet that deflects and scans the particle beam B in the X direction and a Y deflection scanning magnet that deflects and scans the particle beam B in the Y direction. By controlling the particle beam B, the scanning electromagnet 11 can three-dimensionally conform the narrow particle beam B to the shape of the affected area of the patient P for scanning. That is, the particle beam B emitted from the irradiation port 10 can scan over a predetermined scanning range F in two directions (X direction and Y direction) perpendicular to the beam traveling direction.

As shown in FIG. 2, inside the rotating gantry 5, a treatment space 12 for performing particle beam therapy is provided. A patient P is placed on a treatment table 13 provided in this treatment space 12 . The treatment table 13 is movable with the patient P placed thereon. By moving the treatment table 13, the patient P can be moved to the irradiation position of the particle beam B and aligned. Therefore, the lesion tissue of the patient P can be irradiated with the particle beam B with optimum accuracy.

Further, by rotating the rotating gantry 5, the irradiation port 10 can be rotated with the patient P as the center. For example, the irradiation port 10 can be rotated clockwise or counterclockwise by 180 degrees around the patient P (rotational axis J) when viewed from the front. Then, the particle beam B can be irradiated from any direction around the patient P. In other words, the rotating gantry 5 is a device capable of changing the irradiation direction of the particle beam B guided by the beam transport line 4 to the patient P. FIG. Therefore, it is possible to accurately irradiate the affected area with the particle beam B from the optimum direction while reducing the burden on the patient P.

The particle beam B loses its kinetic energy as it passes through the body of the patient P, slows down, receives resistance that is approximately inversely proportional to the square of the speed, and stops abruptly when it reaches a certain speed. This stopping point of the particle beam B is called a Bragg peak, and high energy is emitted. By aligning this Bragg peak with the position of the lesion tissue (affected area) of the patient P, the particle beam therapy apparatus 1 can kill only the lesion tissue while suppressing damage to normal tissue.

As shown in FIG. 2 , a treatment space 12 provided inside the rotating gantry 5 is formed integrally with a treatment room 15 connected to a building 14 . The floor, walls, and ceiling of the treatment room 15 on the building 14 side are provided so as to be continuous with the treatment space 12 . The treatment table 13 is fixed to the floor of the treatment room 15 on the building 14 side. That is, even if the rotating gantry 5 and the irradiation port 10 are rotated, the position of the treatment table 13 does not change.

In addition, the patient P enters the treatment space 12 through the treatment room 15 . When viewing the irradiation port 10 from the treatment room 15, the surface facing the line-of-sight direction G1 of the patient P, that is, the surface visible from the patient P is the front side of the irradiation port 10, and the opposite surface is the rear surface of the irradiation port 10. described as a side.

An inner wall portion 16 is provided inside the rotating gantry 5 . The inner wall portion 16 has a disk shape, and its peripheral edge is supported by a support portion 17 provided along the entire inner peripheral surface of the rotating gantry 5 . The inner wall portion 16 is supported by a support portion 17 so as to be freely rotatable in the circumferential direction. The inner wall portion 16 partitions the inside of the rotating gantry 5 into a treatment space 12 portion and other portions.

A reverse rotation synchronous motor 18 is connected to the central portion of the inner wall portion 16 on the side opposite to the treatment space 12 . This reverse rotation synchronous motor 18 is fixed to the inner peripheral surface of the rotating gantry 5 . When the rotating gantry 5 is rotated by the driving force of the drive motor 8 , the reverse rotation synchronous motor 18 rotates the inner wall portion 16 in a direction opposite to the rotating direction of the rotating gantry 5 .

For example, when rotating the rotating gantry 5 clockwise in a front view, the inner wall portion 16 is rotated counterclockwise. At this time, the rotational speed of the rotating gantry 5 and the rotational speed of the inner wall portion 16 are made the same. That is, the inner wall portion 16 appears stationary even when the rotating gantry 5 is rotated. A decorative wall 19 is provided on the treatment space 12 side of the inner wall portion 16 to hide the inner wall portion 16 from being seen from the treatment space 12 side.

Inside the rotating gantry 5, there are a front side track rail 20a provided on one end side (front side), a rear side track rail 20b provided on the other end side (rear side), and these track rails. A plurality of moving floors 21 spanning between 20a and 20b are provided.

The moving floor 21 is a rectangular plate-like member elongated in the front-rear direction. The moving floor 21 forms the floor, walls and ceiling of the treatment space 12 . The track rail 20a on the front side is fixed to the floor, wall, and ceiling of the treatment room 15 on the building 14 side. On the other hand, the track rail 20 b on the rear side is fixed to the inner wall portion 16 . Even if the rotating gantry 5 and the irradiation port 10 rotate, the front and rear track rails 20a, 20b remain stationary without rotating.

The movable floor 21 spanned over the track rails 20a and 20b is aligned along the track rails 20a and 20b and is movable along the track rails 20a and 20b. When the irradiation port 10 is rotated along with the rotation of the rotating gantry 5, the movable bed 21 is moved along with the rotation of the irradiation port 10. FIG. Then, even if the irradiation port 10 is moved to any position, the moving floor 21 maintains the floor, walls, and ceiling of the treatment space 12 .

In this way, the floor, walls and ceiling of the treatment space 12 are formed by the decorative wall 19 and the moving floor 21, so that the patient P in the treatment space 12 does not need to use the mechanical members that make up the rotating gantry 5. is hidden from view. Therefore, the appearance of the interior of the treatment space 12 can be improved. In addition, since it is possible to prevent the patient P from feeling that he or she is inside a huge apparatus, the patient P does not feel a sense of psychological oppression.

3 to 5 are cross-sectional views of the irradiation port 10 as viewed from the rear. In addition, in FIG. 3, the case where the irradiation port 10 is arrange|positioned above the patient P is illustrated. Here, since the irradiation port 10 is rotated along with the rotation of the rotating gantry 5, the irradiation port 10 may be arranged below the patient P in some cases. In that case, the configuration of the irradiation port 10 in FIG. 3 is inverted upside down. For convenience of explanation, the state in which the irradiation port 10 is arranged above the patient P is defined as a fixed position, and the upper side of the irradiation port 10 in FIGS. 6 and 7 are cross-sectional views of the irradiation port 10 in plan view. 6 and 7 are described as the front side (front side) of the irradiation port 10 .

As shown in FIG. 3, inside the irradiation port 10, a beam emitting section 30 is provided. A particle beam B is emitted toward the affected area K of the patient P through the beam emitting unit 30 . The position and orientation of the beam emitting unit 30 with respect to the patient P can be changed according to the rotation of the rotating gantry 5 .

The beam emission part 30 is the downstream end of the vacuum duct D extending from the beam transport line 4, and is the part where the particle beam B guided along the vacuum duct D is emitted into the atmosphere. The opening at the downstream end of the vacuum duct D that forms the beam emission part 30 is closed with a polyimide film, so that the particle beam B can be emitted while the inside of the vacuum duct D is kept vacuum. That is, the opening at the downstream end of the vacuum duct D serves as a thin-film vacuum window through which the particle beam B emerges.

The irradiation port 10 has an irradiation port cover 31 and a body cover 32 . Furthermore, the irradiation port 10 has a beam output section 30 covered by an irradiation port cover 31 . The irradiation port cover 31 is the part that is closest to the patient P and forms a substantially square shape when viewed from the rear. The trunk cover 32 is a portion forming a substantially trapezoidal shape when viewed from the rear. The irradiation port cover 31 and the body cover 32 are made of a nonmetallic material such as synthetic resin (for example, GFRP). Also, the irradiation port cover 31 and the body cover 32 are attached to a frame 33 fixed to the inner peripheral surface of the rotating gantry 5 . A vacuum duct D arranged inside the rotating gantry 5 is covered with an irradiation port cover 31 and a body cover 32 .

The mount 33 is formed by combining a plurality of metal frames. Also, the vacuum duct D and the scanning electromagnet 11 are supported by a frame 33 .

A dose monitor 34 , a position monitor 35 and a range shifter 36 are provided below the beam emission unit 30 . The dose monitor 34 is a device that measures the dose of the particle beam B emitted from the beam emission section 30 . The position monitor 35 is a device that measures the position of the particle beam B emitted from the beam emission section 30 . The range shifter 36 is a device that adjusts the flight distance (stop position) of the particle beam B. FIG. That is, the range shifter 36 adjusts the position where the Bragg peak occurs in the depth direction inside the patient's P body.

The inside of the dose monitor 34 is filled with gas that is ionized when the particle beam B passes through. Electrodes and wires are provided in the space filled with this gas. When the particle beam B passes through the dose monitor 34, the gas is ionized and current flows between the electrode and the wire. Using this principle, the intensity of the particle beam B is measured.

The inside of the position monitor 35 is also filled with gas that is ionized when the particle beam B passes through. Then, the gas is ionized by the particle beam B, and the passing position of the particle beam B is measured using the principle that the current flows between the electrode and the wire.

Inside the irradiation port 10, a first energy modulating section 41 and a second energy modulating section 42 are provided below the portion where the dose monitor 34, the position monitor 35, and the range shifter 36 are provided. The first and second energy modulators 41 and 42 are members for expanding the range in which the Bragg peak of the passing particle beam B occurs in the direction of travel of the beam.

In the first embodiment, the scanning electromagnet 11, the dose monitor 34, the position monitor 35, the range shifter 36, the second energy modulating section 42, and the first energy modulating section 41 are arranged in order from the upstream side to the downstream side of the particle beam B. lined up with That is, the first energy modulation section 41 is provided at the position closest to the patient P. As shown in FIG. The upstream side of the particle beam B is the side away from the patient P, and the downstream side of the particle beam B is the side closer to the patient P. For example, in FIG. 3, the upper side of the paper is the upstream side.

The first and second energy modulators 41 and 42 are provided downstream of irradiation-related components including the scanning electromagnet 11 , the dose monitor 34 , the position monitor 35 and the range shifter 36 . In other words, components related to irradiation are not arranged downstream of the first and second energy modulation units 41 and 42 . In addition, the parts related to irradiation indicate the parts related to the control or measurement of the particle beam B. FIG.

The first and second energy modulators 41 and 42 of the first embodiment are composed of flat ridge filters. These first and second energy modulators 41 and 42 form a square shape in plan view (see FIG. 7). A ridge filter is sometimes called a mini-ridge filter or a ripple filter, but these terms are synonymous.

The first energy modulation unit 41 is always arranged on the trajectory of the particle beam B when the particle beam B is irradiated. In addition, the second energy modulation section 42 is movable between a position retracted from the trajectory of the particle beam B and a position overlapping the first energy modulation section 41 . That is, the second energy modulation section 42 is replaceable. In the first embodiment, the retracted position of the particle beam B is outside the irradiation port cover 31 .

As shown in FIG. 8, a plurality of ridge bars 43 are formed on the surfaces of the first and second energy modulation sections 41 and 42 as ridge filters. These ridge bars 43 are portions that form a mountain shape (triangular shape) in side view and extend linearly in plan view. The multiple ridge bars 43 are arranged parallel to each other in a plan view. That is, a plurality of ridge bars 43 are periodically arranged in one-dimensional direction. In addition, in FIG. 8, the ridge bar 43 is enlarged and shown in order to help an understanding.

The width dimension R1 of the ridge bar 43 must be sufficiently small. The width dimension R1 of this ridge bar 43 is formed to be equal to or less than the beam diameter of the particle beam B. As shown in FIG. For example, when the beam diameter dimension of the particle beam B is 1 mm, the width dimension R1 of the ridge bar 43 is formed to be 1 mm or less. Note that the width dimension R1 of the ridge bar 43 of the first and second energy modulation portions 41 and 42 may be different.

As shown in FIG. 9, one ridge bar 43 has a mountain shape in a side view by forming a plurality of stepped portions 44 . By forming these ridge bars 43, the ridge filter is formed with a thick peak portion and a thin valley portion.

For example, the energy of the particle beam B1 that has passed through the peaks is attenuated more than the energy of the particle beam B2 that has passed through the valleys. That is, in the body of the patient P, the particle beam B1 that has passed through the peaks is stopped at a shallower position than the particle beam B2 that has passed through the valleys. Thus, the ridge filter can change the energy distribution of the particle beam B by having different thicknesses depending on the ridge bar 43 .

FIG. 12 is a graph showing the relationship between the dose given to the body tissue of the patient P by the irradiation of the particle beam B and the depth. The vertical axis indicates the normalized relative dose based on the particle beam B, and the horizontal axis indicates the depth from the patient's P body surface. In this graph, the solid line indicates the particle beam B emitted using the ridge filter, and the dotted line indicates the particle beam B emitted without using the ridge filter. A particle beam B is irradiated toward an affected area K within a predetermined depth range Q1 inside the patient's P body.

As shown in the dotted line graph, in the particle beam B that has not passed through the ridge filter, the range Q2 in the depth direction where the Bragg peak occurs, that is, the so-called width is narrow. On the other hand, as shown in the solid line graph, in the particle beam B that has passed through the ridge filter, the range Q2 in the depth direction where the Bragg peak occurs expands. That is, the Bragg peak is widened by passing the particle beam B through the ridge filter.

When the width of the Bragg peak is narrow, when irradiating the entire area Q1 of the affected area K with the particle beam B, a large number of irradiations must be performed. On the other hand, since the Bragg peak is widened by the ridge filter, the Bragg peak can be generated in a wide range with one irradiation, so the number of times of irradiation with the particle beam B can be reduced. That is, the irradiation time of the particle beam B can be shortened. Furthermore, errors in irradiation positions can be mitigated.

Specifically, as shown in FIG. 13, when the particle beam B is irradiated, a plurality of layers of slice planes 80 are set on the affected area K in a line in the depth direction of the body. Then, the particle beam B is sequentially irradiated with an output corresponding to each slice plane 80 . A ridge filter is selected so as to correspond to the interval of the slice planes 80, and the Bragg peak width of the particle beam B is set. That is, a ridge filter is set for each affected area K to be irradiated.

As shown in FIG. 14 , an irradiation spot 81 is scanned along the slice plane 80 when the particle beam B is irradiated onto the slice plane 80 . By sequentially changing the position of the irradiation spot 81 by this scanning, the energy of the particle beam B is applied to the entire slice surface 80 . Furthermore, by irradiating all slice planes 80 with the particle beam B, the energy of the particle beam B is applied to the entire affected area K. FIG.

As shown in FIG. 9, the height dimension R2 and the width dimension R3 of each stepped portion 44 in the ridge bar 43 do not have to be constant dimensions, and are appropriately set according to the Bragg peak generated by the particle beam B. . The height dimension R2 and the width dimension R3 of each stepped portion 44 are set so that the dose of the passing particle beam B exhibits a Gaussian distribution.

The relationship between the energy modulators 41 and 42 and the graphs of the Gaussian distributions 91 and 92 will be described with reference to FIGS. 17, 18 and 19. FIG. The horizontal axis of the graph indicates the depth direction. Here, as shown in FIG. 17, the dose of the particle beam B is set so that the dose of the particle beam B exhibits a Gaussian distribution 91 even when the first energy modulation section 41 is used alone. When the first energy modulation section 41 is used alone, an energy distribution 95 that approximates the Gaussian distribution 91 is actually produced by the Bragg peaks 93 corresponding to the stepped sections 44 .

As shown in FIG. 18, when the second energy modulation section 42 is used alone, the energy distribution 96a is generated by the Bragg peaks 94a corresponding to the stepped sections 44. energy distribution 96a. That is, the energy distribution 96 a does not approximate the Gaussian distribution 92 .

As shown in FIG. 19 , the second energy modulation section 42 is used in combination with the first energy modulation section 41 to set the dose of the particle beam B so as to exhibit a Gaussian distribution 92 . That is, the first energy modulation section 41 widens the Bragg peak of the passing particle beam B to compensate for the widening of the Bragg peak formed by the second energy modulation section 42 . In this way, a Bragg peak of the required width can be generated. When two energy modulators 41 and 42 are used, an energy distribution 96b that approximates the Gaussian distribution 92 actually occurs due to the Bragg peak 94b.

For example, when there are four required Bragg peak widths of 1 mm, 2 mm, 3 mm, and 4 mm, the first energy modulation section 41 always arranged in the irradiation port 10 corresponds to the smallest width of 1 mm. do. Here, by appropriately exchanging the three types of second energy modulation sections 42, it is possible to correspond to any Bragg peak width of 1 mm, 2 mm, 3 mm, and 4 mm.

When forming the ridge bar 43 on the ridge filter, the surface of the flat plate forming the base of the ridge filter is drilled to form each stepped portion 44 . That is, the ridge bar 43 is formed by cutting. The ridge bar 43 is a very small portion with a width and height of several millimeters, and requires precision.

Specifically, the Bragg peak that varies depending on the configuration of the ridge bar 43 differs depending on the dimensions of each stepped portion 44 . Here, the relationship between the dimensions of the stepped portions 44a and 44b and the Bragg peak will be described with reference to FIGS. 15 and 16. FIG. FIG. 15 shows the steps 44a, 44b of the ridge bar 43 with different dimensions. FIG. 16 shows the Bragg peaks corresponding to each step 44a, 44b. The horizontal axis of this graph indicates the depth direction.

As shown in FIG. 15, a stepped portion 44a having the highest height dimension R6 and a stepped portion 44b having a lower height dimension R7 are illustrated. The dimensions of the stepped portions 44a and 44b are appropriately set according to the desired Bragg peaks 83 and 84. As shown in FIG.

FIG. 16 shows a graph of the Bragg peak 82 when no ridge filter is used, the Bragg peak 83 when passing the high step 44a, and the Bragg peak 84 when passing the low step 44b. . As shown in this graph, the Bragg peak 84 when passing through the low step portion 44b is displaced to a shallower position than the Bragg peak 82 when the ridge filter is not used. Also, the Bragg peak 83 when passing through the high stepped portion 44a is displaced to a shallower position. Thus, in order to generate a given Gaussian distribution 90, these Bragg peaks 83 and 84 must be set appropriately.

As shown in FIG. 15, the width dimension R8 of the high stepped portion 44a needs to be narrower than the width dimension R9 of the low stepped portion 44b. That is, the width dimension R8 of the step portion 44a becomes narrower as the height dimension R6 increases. Therefore, the higher the ridge bar 43 is, the more difficult it is to process.

As shown in FIG. 10 , the height dimension R4 of the ridge bar 43 of the first energy modulation section 41 is lower than the height dimension R5 of the ridge bar 43 of the second energy modulation section 42 . In this way, the working accuracy of the ridge bar 43 can be maintained. Further, the height dimensions R4 and R5 of the ridge bar 43 of the first energy modulation section 41 and the ridge bar 43 of the second energy modulation section 42 can be suppressed. For example, in order to widen the Bragg peak of the particle beam B, the ridge bar 43 needs to be raised. However, if the ridge bar 43 is raised, the ridge bar 43 becomes elongated and difficult to machine. In this embodiment, two ridge filters are used to suppress the height dimensions R4 and R5 of the respective ridge bars 43, thereby widening the Bragg peak and maintaining the working accuracy of the ridge bars.

In the first embodiment, the first energy modulation section 41 has the property of being able to widen the Bragg peak by itself. In this way, the first energy modulation section 41 can be used alone for widening the Bragg peak. Further, the second energy modulation section 42 cannot widen the Bragg peak by itself, and has a property that it can widen the Bragg peak by overlapping with the first energy modulation section 41 . In this way, since it is not necessary to use the second energy modulating section 42 alone, it is possible to reduce the manufacturing accuracy of the second energy modulating section 42 and reduce the cost as compared with the case of using the second energy modulating section 42 alone. Furthermore, the mode of combination of the first energy modulating section 41 and the second energy modulating section 42 can be simplified, and the procedure for exchanging the second energy modulating section 42 can be simplified, and the device can be simplified.

For example, when using the second energy modulation unit 42 alone, when changing from a predetermined Bragg peak width to another Bragg peak width, the first energy modulation unit 41 is removed, and instead the second energy modulation unit A two-step procedure to incorporate 42 is required. On the other hand, in the first embodiment, the same change can be made in one step of incorporating the second energy modulation section 42 while leaving the first energy modulation section 41 as it is.

Furthermore, for example, when the second energy modulating section 42 is used alone, there is a possibility that the first energy modulating section 41 may be removed, so a corresponding insertion and retraction mechanism is required. On the other hand, in the first embodiment, it is sufficient to have a mechanism for inserting and retracting only for the second energy modulation section 42, and the number of parts can be reduced.

The first and second energy modulating sections 41 and 42 of the first embodiment consist of ridge filters made of aluminum. By doing so, the first and second energy modulation sections 41 and 42 can be formed thin.

Note that the first and second energy modulation sections 41 and 42 may be ridge filters made of acrylic. In this way, machining becomes easier, so the manufacturing cost of the first and second energy modulation sections 41 and 42 can be reduced.

The ridge bar 43 of the ridge filter of the first embodiment has a mountain shape (isosceles triangle shape) in side view. may be other than mountain-shaped. For example, the ridge bar may be semicircular, right triangular, square, or trapezoidal.

As shown in FIG. 11, the first and second energy modulators 41 and 42 are arranged one above the other, but are arranged such that the directions of the respective ridge bars 43 are different from each other by 90 degrees. For example, among the four axes (X direction, −X direction, Y direction, −Y direction) extending in four directions in the radial direction of the particle beam B, the ridge bar 43 of the first energy modulation unit 41 is on the Y axis. When extending along the X axis, the ridge bar 43 of the second energy modulation section 42 extends along the X axis. That is, the ridge bars 43 of the first and second energy modulation sections 41 and 42 intersect with each other in plan view. By doing so, the dose of the passing particle beam B will exhibit an appropriate Gaussian distribution.

As shown in FIG. 4, the irradiation port cover 31 has a U shape in cross section, and the first energy modulation section 41 is arranged at the bottom thereof. The first energy modulation section 41 is provided on the rear surface of the bottom of the irradiation port cover 31, that is, on the surface invisible to the patient P. As shown in FIG.

A connection portion 37 that holds the edge of the first energy modulation portion 41 is formed on the back surface of the irradiation port cover 31 . The connecting portion 37 provides the first energy modulating portion 41 corresponding to the portion of the irradiation port cover 31 closest to the patient P. As shown in FIG. The first energy modulation section 41 may be fixed to the connection section 37 using screws. Note that the connecting portion 37 serves as a position defining portion that defines the position of the first energy modulating portion. By doing so, the first energy modulation section 41 can be provided at a position corresponding to the irradiation port cover 31 .

The connecting portion 37 as the position regulating portion of the first embodiment constitutes an engaging piece engaged with the edge of the first energy modulating portion 41 . That is, the position defining portion is a portion of the irradiation port cover 31 that has a shape in which the first energy modulation portion 41 is arranged. In this way, since the first energy modulating section 41 is arranged on the irradiation port cover 31, the position of the first energy modulating section 41 can be defined accurately.

The ridge filter has a secondary property of scattering the particle beam B. Scattering means that the diameter of the particle beam B expands. When the particle beam B is scattered, its diameter increases with distance from the ridge filter to the downstream side. On the other hand, in the first embodiment, since the position of the first energy modulation section 41 substantially coincides with the portion of the irradiation port cover 31 closest to the patient P, the Bragg peak of the particle beam B is widened. , the radial spread of the particle beam B can be minimized. That is, dose concentration to the affected area K can be enhanced.

In the first embodiment, a plurality of energy modulation units 41 and 42 are arranged along the trajectory of the particle beam B, but at least one energy modulation unit 41 corresponds to the irradiation port cover 31. It would be nice if it was provided. By doing so, the plurality of energy modulation sections 41 and 42 can correspond to the target Bragg peak, so that the individual energy modulation sections 41 and 42 can be manufactured easily.

The first energy modulation section 41 is supported by the irradiation port cover 31 . The irradiation port cover 31 is detachably attached to the pedestal 33 using a predetermined connection jig. During maintenance, when the first energy modulation unit 41 is to be attached or replaced, the irradiation port cover 31 is removed from the pedestal 33 before the work is performed. The first energy modulation section 41 is detachably supported by the mount 33 together with the irradiation port cover 31 . In this way, since the first energy modulation section 41 is attached and detached together with the irradiation port cover 31, the maintenance work of the first energy modulation section 41 can be easily performed.

The first energy modulation section 41 is fixedly arranged on the irradiation port cover 31 and is a member that does not need to be replaced for each patient P. As shown in FIG. In other words, the first energy modulation section 41 is a member that is always arranged on the trajectory of the particle beam B when the particle beam B is irradiated, regardless of the Bragg peak width required for the affected area K. On the other hand, the second energy modulation section 42 is a member that can be replaced according to the Bragg peak width required for the affected area K.

As shown in FIGS. 4 and 6, an opening 38 is formed on the right side surface of the irradiation port cover 31 when viewed from the back. A vertical dimension M1 and a horizontal dimension M2 (opening dimension) of the opening 38 are dimensions that allow the second energy modulation section 42 to pass therethrough. In this way, the second energy modulation section 42 can be put in and taken out of the irradiation port cover 31 through the opening 38 without removing the irradiation port cover 31 during maintenance.

Inside the irradiation port cover 31, a guide portion 45 is provided to guide the insertion and withdrawal of the second energy modulation portion 42. As shown in FIG. Further, a movement holding portion 46 that holds at least part of the guide portion 45 and moves the guide portion 45 in and out of the opening portion 38 is provided. Note that the movable holding unit 46 is fixed to the base 33 . The guide portion 45 is movably held with respect to the movement holding portion 46 . The movement holding portion 46 is a rail extending in the horizontal direction, and the guide portion 45 can move in the horizontal direction along this rail.

A portion where the second energy modulation section 42 is arranged when the guide section 45 is housed inside the irradiation port cover 31 serves as a placement section 47 (connection section). This placement section 47 is provided at a position on the trajectory of the particle beam B. As shown in FIG. The guide section 45 moves the second energy modulation section 42 between a position on the trajectory of the particle beam B (placement section 47) and a position retracted from the trajectory.

Further, the guide part 45 is fixed by a predetermined fixing mechanism provided in the movement holding part 46 when stored inside the irradiation port cover 31 . Therefore, even if the irradiation port 10 is tilted as the rotating gantry 5 rotates, the fixed state of the guide portion 45 to the pedestal 33 can be maintained.

The irradiation port cover 31 is provided with a lid portion 39 that closes the opening portion 38 . When the guide portion 45 is to be taken in and out, the lid portion 39 is opened. In addition, in this embodiment, a lid driving portion 51 for opening and closing the lid portion 39 and a guide driving portion 52 for driving the guide portion 45 are provided (see FIG. 20).

As shown in FIGS. 4 and 6 , an operation section 40 is provided near the opening 38 of the irradiation port cover 31 . When the operator operates the operating portion 40, the lid portion 39 or the guide portion 45 is driven. Further, the guide portion 45 is provided with a latch portion 48 (connection portion) that restrains the second energy modulation portion 42 . In addition, in this embodiment, a latch driving section 53 for driving the latch section 48 is provided (see FIG. 20). By operating the operation unit 40 by the operator, the restraint and release of the second energy modulation unit 42 by the latch unit 48 can be automatically performed. In this way, a maintenance worker can release the restraint of the latch portion 48 from the outside of the irradiation port cover 31, thereby improving maintainability.

The latch section 48 sandwiches the second energy modulating section 42 from above and below and restrains the second energy modulating section 42 at a plurality of locations. In this way, even if the irradiation port 10 is turned upside down due to the rotation of the rotating gantry 5, the fixed state of the second energy modulation section 42 with respect to the guide section 45 can be maintained.

It should be noted that the entire second energy modulation section 42 does not need to be pulled out from the opening 38 , and a part of the second energy modulation section 42 may be pulled out from the opening 38 . Alternatively, the operator may put his or her hand through the opening 38 to access the second energy modulation section 42 and perform the attachment/detachment work.

As shown in FIGS. 5 and 7, when replacing the second energy modulation section 42 arranged in the arrangement section 47 with a replacement second energy modulation section 42′, the operator operates the operation section 40. By doing so, the lid portion 39 is driven and the opening portion 38 is automatically opened. Further, the guide portion 45 is driven to automatically pull out the second energy modulation portion 42 from the opening portion 38 . Then, the operator operates the operation portion 40 to release the latch portion 48 and remove the second energy modulation portion 42 from the guide portion 45 . After that, the replacement second energy modulation section 42 ′ is attached to the guide section 45 , and the second energy modulation section 42 is restrained by the latch section 48 again. When the operator operates the operating portion 40 , the guide portion 45 automatically returns to the inside of the irradiation port cover 31 and the opening portion 38 is closed by the lid portion 39 .

In the first embodiment, since the guide portion 45 is moved along the movable holding portion 46 , the operator can easily insert and remove the second energy modulation portion via the guide portion 45 .

Note that the mount 33 is provided with a position detection sensor 54 for detecting that the guide portion 45 exists at a fixed position. That is, it can be confirmed by the position detection sensor 54 that the second energy modulation section 42 is arranged in the arrangement section 47 . In addition, the latch section 48 is provided with a latch sensor 55 that detects that the second energy modulation section 42 is properly restrained.

In the first embodiment, the latch sensor 55 confirms that the second energy modulation section 42 is properly restrained, and the position detection sensor 54 confirms that the second energy modulation section 42 is arranged in the arrangement section 47. do.

Since the second energy modulation section 42 is constrained by the latch section 48 when the second energy modulation section 42 is arranged in the placement section 47, the position of the second energy modulation section 42 may be displaced from the placement section 47. disappears.

A first tag 56 is attached to the first energy modulation section 41 , and a second tag 57 is attached to the second energy modulation section 42 . These first and second tags 56, 57 are composed of RFID tags. These first and second tags 56 and 57 store identification information that can identify the respective energy modulators 41 and 42 . Further, the mount 33 is provided with a non-contact first tag reader 58 for reading the first tag 56 and a non-contact second tag reader 59 for reading the second tag 57 .

The second energy modulation section 42 is a member that is replaced according to the depth position of the affected area K. As shown in FIG. Therefore, by reading the identification information of the second tag 57, it is possible to confirm whether or not the appropriate second energy modulator 42 is set. By this confirmation, even if the operator sets the wrong second energy modulating section 42, it is possible to inform the operator by giving a predetermined notification. By reading the identification information of the first tag 56, it is possible to confirm whether or not the appropriate first energy modulator 41 is set.

In the first embodiment, the second energy modulation section 42 is inserted and removed from the inside of the irradiation port cover 31 through the opening 38 only in one direction. A direction in which the second energy modulation section 42 is inserted and removed is called a specific direction. That is, the opening 38 is opened in a portion of the irradiation port cover 31 corresponding to the specific direction. In this way, the replacement work of the second energy modulation unit 42 can be easily performed without removing the irradiation port cover 31 from the pedestal 33, and the replacement work can be simplified, thereby improving maintainability. can be made

In the first embodiment, the second energy modulation section 42 can be inserted and retracted along a specific direction corresponding to one of the four axes extending in the radial direction of the beam around the particle beam B. It has become. For example, as shown in FIG. 11, of the four axes (X direction, −X direction, Y direction, −Y direction) extending in four directions in the radial direction of the particle beam B, the Y direction is the irradiation port cover. 31, and the −Y direction is the rear side of the irradiation port cover 31, the specific direction is only the X direction. That is, the second energy modulating section 42 is inserted into and retracted from the arrangement section 47 along one specific direction.

In this way, the moving distance when inserting and retracting the second energy modulation section 42 can be shortened. In addition, since the second energy modulation section 42 is accessed only from one direction of the irradiation port cover 31, the size of the irradiation port cover 31 can be reduced.

As shown in FIG. 3 , the outer surface of the lid portion 39 when closing the opening 38 is flush with the outer surface of the irradiation port cover 31 . By doing so, the opening 38 becomes inconspicuous, so that the appearance of the irradiation port cover 31 can be improved.

The opening 38 is provided on a side surface of the irradiation port cover 31 other than the surface facing the treatment table 13 . That is, the opening 38 is provided on the side surface of the irradiation port cover 31 other than the bottom surface. With this configuration, the opening 38 is not visible from the patient P placed on the treatment table 13, so that the appearance of the irradiation port cover 31 can be improved. The opening 38 should not be provided on the front or back of the irradiation port cover 31 .

As shown in FIGS. 2 and 3, when the surface visible from one end of the rotating gantry 5 in the line-of-sight direction G2 along the rotation axis J is the front of the irradiation port cover 31, an opening is provided on the side other than the front. 38 are provided. In this way, when the patient P looks at the irradiation port cover 31 from the entrance side of the treatment space 12, the opening 38 cannot be seen, so the appearance of the irradiation port cover 31 can be improved.

Further, the opening 38 is provided on a side surface other than the surface facing the rotation axis J of the irradiation port cover 31 . With this configuration, the opening 38 is not visible in the line-of-sight direction G2 when the irradiation port cover 31 is viewed from the patient P who is placed on the treatment table 13 and is on the rotation axis J, so that the irradiation port cover 31 looks good. can be improved. In addition, since the structure reminiscent of a machine such as the opening 38 can be hidden from the patient P, the patient P does not feel oppressive.

As shown in FIGS. 3 and 11 , the second energy modulating section 42 is arranged upstream of the first energy modulating section 41 in the direction in which the particle beam B travels. In this way, the first energy modulation section 41, which mainly sets the broadening of the Bragg peak, is close to the patient P, so that the radial spread of the particle beam B can be suppressed at all times.

A scanning electromagnet 11 is arranged upstream of the first and second energy modulators 41 and 42 . Also, the area N1 of the first energy modulation section 41 is larger than the area N2 of the second energy modulation section 42 . The particle beam B scans the diseased area K while swinging laterally by the scanning electromagnet 11 .

In the first embodiment, the area N1 of the first energy modulating section 41 is larger than the area N2 of the second energy modulating section 42, so the areas N1 and N2 of the energy modulating sections 41 and 42 are set to the particle beam. It can be according to the scanning range of the beam B.

Next, the system configuration of the particle beam therapy system 1 will be described with reference to the block diagram shown in FIG.

As shown in FIG. 20 , the particle beam therapy system 1 includes an irradiation control system 50 that controls the irradiation port 10 . The irradiation control system 50 is realized by executing a program stored in a memory or HDD by a CPU.

The irradiation control system 50 includes a scanning electromagnet 11, a dose monitor 34, a position monitor 35, a range shifter 36, an operation section 40, a lid drive section 51, a guide drive section 52, a latch drive section 53, and position detection. sensor 54, latch sensor 55, first tag reading unit 58, second tag reading unit 59, notification output unit 60, setting storage unit 61, placement determination unit 62, tag determination unit 63, irradiation and a control unit 64 .

The notification output unit 60 issues a predetermined notification when the second energy modulation unit 42 is replaced. The notification output unit 60 may be a display that displays notification information or a speaker that outputs notification sounds. Note that the notification output unit 60 is provided in the irradiation port 10 . Note that the notification output unit 60 may be provided in the control computer in the control room where the engineer is present.

The setting storage unit 61 stores setting information regarding the patient P and the affected area K necessary for particle beam therapy. This setting information includes information on the position and range of the affected area K, information on the dose to be applied to the affected area K, and information on the first and second energy modulators 41 and 42 . The setting storage unit 61 is provided in the control computer in the control room. The setting information is input to the setting storage unit 61 before the particle beam therapy is started, especially before the second energy modulation unit 42 is replaced.

The placement determination unit 62 determines whether or not the second energy modulation unit 42 is placed in the placement unit 47 based on detection by the position detection sensor 54 and the latch sensor 55 . This determination result is sent to the irradiation control unit 64 . By doing so, it is possible to grasp whether or not the second energy modulation section 42 is arranged in the arrangement section 47 .

The tag determination section 63 determines whether or not the appropriate tags 56 and 57 have been read by the tag reading sections 58 and 59 based on the identification information read by the tag reading sections 58 and 59 . This determination result is sent to the irradiation control unit 64 . Note that the determination by the tag determination unit 63 is performed by comparing with setting information stored in the setting storage unit 61 in advance.

The irradiation control unit 64 controls each device of the irradiation port 10 . This irradiation control unit 64 controls the scanning electromagnet 11 and the range shifter 36 . Note that the irradiation control unit 64 acquires information indicating the control result of the particle beam B from the scanning electromagnet 11 .

The irradiation control unit 64 also acquires information about the particle beam B from the dose monitor 34 and the position monitor 35 . Furthermore, the irradiation control unit 64 controls the notification output unit 60 when performing a predetermined notification.

Also, the irradiation control unit 64 acquires setting information from the setting storage unit 61 . Furthermore, the irradiation control unit 64 causes the setting storage unit 61 to store information on treatment and information on various flags during or after particle beam therapy.

The operating section 40 controls the lid driving section 51 , the guide driving section 52 and the latch driving section 53 . It should be noted that the irradiation control unit 64 acquires information regarding driving of the lid unit 39 and the guide unit 45 from the operation unit 40 . Further, the operation unit 40 acquires from the irradiation control unit 64 information as to whether or not the particle beam therapy is being stopped, that is, whether or not it is safe to drive the lid portion 39 and the guide portion 45. .

Although not shown, the particle beam therapy system 1 includes an accelerator control system that controls the beam generator 2, the circular accelerator 3, and the beam transport line 4, a gantry control system that controls the rotating gantry 5, and a treatment table 13. and a couch control system that controls the The irradiation control unit 64 of the irradiation control system 50 controls the irradiation port 10 while bidirectionally exchanging control information with each of the accelerator control system, the gantry control system, and the treatment table control system.

The system of this embodiment comprises a computer that has hardware resources such as a CPU, ROM, RAM, and HDD, and the CPU executes various programs to realize information processing by software using the hardware resources. be done. Furthermore, the particle beam irradiation method of this embodiment is implemented by causing a computer to execute a program.

Next, replacement processing of the second energy modulator 42 executed by the irradiation control system 50 will be described with reference to the flowcharts of FIGS. 21 and 22. FIG. Note that the block diagram shown in FIG. 20 will be referred to as appropriate.

As shown in FIG. 21, first, in step S11, the irradiation control unit 64 determines whether or not the particle beam therapy system 1 is stopped. That is, it is determined whether the beam generator 2, the circular accelerator 3, the beam transport line 4, and the rotating gantry 5 are stopped. Here, if the particle beam therapy system 1 is not stopped (NO in step S11), the replacement process for the second energy modulation section 42 ends. On the other hand, if the particle beam therapy system 1 is stopped (YES in step S11), the process proceeds to step S12.

In the next step S<b>12 , the operator inputs setting information to the setting storage section 61 . Here, the setting information regarding the replacement second energy modulation section 42' is input. The input of setting information may be automatically performed at a predetermined timing from a host system.

In the next step S<b>13 , the operation unit 40 determines whether or not there is an operation to open the opening 38 . Here, if the operator does not perform the opening operation using the operation unit 40 (NO in step S13), the replacement process for the second energy modulation unit 42 ends. On the other hand, when the operator performs the opening operation using the operation unit 40 (YES in step S13), the process proceeds to step S14.

In the next step S<b>14 , the operating section 40 drives the lid section 39 by the lid driving section 51 to open the opening section 38 .

In the next step S<b>15 , the operation unit 40 drives the guide unit 45 by the guide driving unit 52 to protrude the guide unit 45 from the opening 38 to pull out the second energy modulation unit 42 from the irradiation port cover 31 . . At this time, the guide portion 45 retracts the second energy modulation portion 42 from the arrangement portion 47 along the specific direction. That is, the second energy modulation section 42 moves to a position where it is retracted from the trajectory of the particle beam B. As shown in FIG.

In the next step S<b>16 , the operating section 40 drives the latch section 48 with the latch driving section 53 to release the restraint of the second energy modulating section 42 .

In the next step S17, the operator replaces the second energy modulation section 42 with the latch section 48 released. That is, the operator can access the second energy modulation section 42 through the opening 38 . Here, when the operator finishes replacing the second energy modulation section 42 , the completion operation is performed by the operation section 40 .

In the next step S<b>18 , the operation unit 40 drives the latch unit 48 with the latch driving unit 53 to restrain the second energy modulation unit 42 . Note that when the second energy modulation section 42 is restrained by the latch section 48 , the latch sensor 55 detects this fact.

In the next step S<b>19 , the operation section 40 drives the guide section 45 with the guide driving section 52 to insert the guide section 45 into the opening 38 and pull the second energy modulation section 42 inside the irradiation port cover 31 . At this time, the second energy modulation section 42 is inserted into the placement section 47 along the specific direction by the guide section 45 . That is, the second energy modulation section 42 moves to a position overlapping the first energy modulation section 41 and on the trajectory of the particle beam B. FIG.

In the next step S<b>20 , when the second energy modulation section 42 is arranged in the arrangement section 47 , that is, when the guide section 45 is moved to the fixed position, the position detection sensor 54 detects that fact. At this time, the second energy modulation section 42 is provided on the trajectory of the particle beam B. As shown in FIG.

In the next step S<b>21 , the operating section 40 drives the lid section 39 by the lid driving section 51 to close the opening section 38 .

As shown in FIG. 22 , in the next step S 22 , the first tag reader 58 reads the identification information of the first tag 56 of the first energy modulator 41 arranged on the irradiation port cover 31 .

In the next step S23, the tag determination unit 63 compares the setting information about the first energy modulation unit 41 stored in the setting storage unit 61 and the identification information of the first tag 56 read by the first tag reading unit 58. By comparison, it is determined whether or not the first energy modulation section 41 is appropriate. Here, if the first energy modulation unit 41 is not suitable (NO in step S23), the process proceeds to step S31, the abnormality notification is performed by the notification output unit 60, and the process ends. On the other hand, if the first energy modulator 41 is suitable (YES in step S23), the process proceeds to step S24.

In the next step S<b>24 , the irradiation control section 64 determines whether or not the opening section 38 is closed by the lid section 39 . Here, if the opening 38 is not closed by the lid 39 (NO in step S24), the process proceeds to step S31, the abnormality is notified by the notification output unit 60, and the process ends. On the other hand, if the opening 38 is closed by the lid 39 (YES in step S24), the process proceeds to step S25.

In the next step S<b>25 , the arrangement determination section 62 determines whether or not the second energy modulation section 42 is restrained by the latch section 48 based on detection by the latch sensor 55 . Here, if the second energy modulation section 42 is not restrained by the latch section 48 (NO in step S25), the process proceeds to step S31, the abnormality notification is performed by the notification output section 60, and the process ends. On the other hand, if the second energy modulation section 42 is restrained by the latch section 48 (YES in step S25), the process proceeds to step S26.

In the next step S<b>26 , the placement determination section 62 determines whether or not the second energy modulation section 42 is placed in the placement section 47 based on detection by the position detection sensor 54 . Here, if the second energy modulation section 42 is not arranged in the arrangement section 47 (NO in step S26), the process proceeds to step S31, the abnormality notification is performed by the notification output section 60, and the process ends. On the other hand, if the second energy modulation section 42 is arranged in the arrangement section 47 (YES in step S26), the process proceeds to step S27.

In the next step S<b>27 , the second tag reader 59 reads the identification information of the second tag 57 of the second energy modulator 42 arranged in the arrangement section 47 .

In the next step S28, the tag determination unit 63 compares the setting information about the second energy modulation unit 42 stored in the setting storage unit 61 and the identification information of the second tag 57 read by the second tag reading unit 59. By comparing, it is determined whether or not the second energy modulation section 42 is appropriate. Here, if the second energy modulation unit 42 is not appropriate (NO in step S28), the process proceeds to step S31, the abnormality notification is performed by the notification output unit 60, and the process ends. On the other hand, if the second energy modulator 42 is suitable (YES in step S28), the process proceeds to step S29.

In the next step S29, the irradiation control unit 64 uses the notification output unit 60 to perform completion notification to notify that the replacement work has been normally completed.

In the next step S30, the irradiation control section 64 sets an irradiation permission flag and ends the process.

Next, particle beam therapy processing executed by the irradiation control system 50 will be described using the flowchart of FIG. 23 . Note that the block diagram shown in FIG. 20 will be referred to as appropriate.

As shown in FIG. 23, when starting particle beam therapy, first, in step S41, the irradiation control unit 64 determines whether or not the irradiation permission flag is set. Here, if the irradiation permission flag is not set (NO in step S41), the process proceeds to step S52, the stop notification is performed by the notification output unit 60, and the process ends. On the other hand, if the irradiation permission flag is set (YES in step S41), the process proceeds to step S42.

In the next step S42, the irradiation control unit 64 transmits an irradiation permission signal to the accelerator control system, and outputs the particle beam B. FIG.

In the next step S<b>43 , the irradiation control unit 64 adjusts the scanning direction of the particle beam B by the scanning electromagnet 11 .

In the next step S44, the irradiation control unit 64 measures the dose of the particle beam B by the dose monitor 34 and determines whether or not the dose of the particle beam B is within a normal range. Here, if there is an abnormality in the dose of the particle beam B (NO in step S44), the output of the particle beam B is stopped, the process proceeds to step S52, the stop notification is given by the notification output unit 60, and the process ends. do. On the other hand, if the dose of the particle beam B is within the normal range (YES in step S44), the process proceeds to step S45.

In the next step S45, the irradiation control unit 64 measures the position of the particle beam B by the position monitor 35, and determines whether the position of the particle beam B is within a normal range. Here, if there is an abnormality in the position of the particle beam B (NO in step S45), the output of the particle beam B is stopped, the process proceeds to step S52, the stop notification is performed by the notification output unit 60, and the process ends. do. On the other hand, if the position of the particle beam B is within the normal range (YES in step S45), the process proceeds to step S46.

In the next step S46, the irradiation control unit 64 adjusts the flight distance of the particle beam B by the range shifter 36. FIG.

In the next step S47, the particle beam B passes through the second energy modulator 42. As shown in FIG.

In the next step S48, the particle beam B passes through the first energy modulator 41. As shown in FIG.

In the next step S49, the particle beam B is irradiated toward the patient, and the particle beam B whose Bragg peak is widened by the first and second energy modulation units 41 and 42 reaches the affected area K.

In the next step S50, the irradiation control unit 64 determines whether or not the particle beam therapy has ended. If the particle beam therapy has not ended (NO in step S50), the process returns to step S42. On the other hand, if the particle beam therapy has ended (YES in step S50), the process proceeds to step S51.

In the next step S51, the irradiation control unit 64 clears the irradiation permission flag and ends the process.

In the first embodiment, the particle beam B is irradiated only when the irradiation permission flag is set. In other words, the irradiation of the particle beam B is permitted when it is determined that the second energy modulation section 42 is restrained by the latch section in step S25 described above. In this way, when the second energy modulation section 42 is not restrained by the latch section 48, the particle beam B is not irradiated, so an interlock can be configured.

Further, when it is determined that the second energy modulation section 42 is arranged in the arrangement section 47 in step S26 described above, the irradiation of the particle beam B is permitted. In this way, when the second energy modulation section 42 is not arranged in the arrangement section 47, the particle beam B is not irradiated, so an interlock can be configured.

(Second embodiment)
Next, the irradiation port 10A of the particle beam therapy system 1A of the second embodiment will be explained using FIG. The same reference numerals are assigned to the same components as those shown in the above-described embodiment, and overlapping descriptions are omitted.

As shown in FIG. 24, in the second embodiment, the first energy modulator 41 is fixed to the pedestal 33 . Also, the second energy modulation section 42 is detachably attached to the rear surface of the bottom of the irradiation port cover 31A via the connection section 37 . That is, the second energy modulation section 42 is provided below the first energy modulation section 41 . In addition, in the second embodiment, the rear surface of the bottom portion of the irradiation port cover 31A serves as the placement portion 47 . Also, the connecting portion 37 of the irradiation port cover 31A serves as a position defining portion.

Thus, the second energy modulation section 42 of the second embodiment is arranged downstream of the first energy modulation section 41 in the direction in which the particle beam B travels. In addition, in the second embodiment, the opening 38 (see FIG. 4) is not provided on the side surface of the irradiation port cover 31A.

Also, the area of the second energy modulation section 42 is wider than the area of the first energy modulation section 41 . By doing so, the areas of the respective energy modulation units 41 and 42 can be set according to the scanning range of the particle beam B. FIG.

When performing the replacement work of the second energy modulation unit 42 , the irradiation port cover 31 A is removed from the mount 33 . Then, the second energy modulation section 42 is removed from the irradiation port cover 31A, and a replacement second energy modulation section 42' is attached.

In the second embodiment, the second energy modulation section 42 can be provided in the portion closest to the patient P in the irradiation port 10A. In addition, since it becomes easier to access the second energy modulation section 42 from the downstream side in the traveling direction of the particle beam B, the replacement work of the second energy modulation section 42 can be easily performed.

(Third embodiment)
Next, the irradiation port 10B of the particle beam therapy system 1B of the third embodiment will be explained using FIG. The same reference numerals are assigned to the same components as those shown in the above-described embodiment, and overlapping descriptions are omitted.

As shown in FIG. 25 , in the third embodiment, the first energy modulating section 41 is fixed to the pedestal 33 . Further, an opening 71 in which the second energy modulation section 42 is arranged is opened at the bottom of the irradiation port cover 31B. That is, the second energy modulation section 42 is provided below the first energy modulation section 41 .

A connection portion 37 to which the second energy modulation portion 42 is detachably connected is provided on the edge of the opening 71 at the bottom of the irradiation port cover 31B. In addition, in the third embodiment, the opening 71 at the bottom of the irradiation port cover 31B serves as the arrangement portion. Also, the connecting portion 37 of the irradiation port cover 31B serves as a position defining portion.

Thus, the second energy modulation section 42 of the third embodiment is arranged downstream of the first energy modulation section 41 in the direction in which the particle beam B travels. Note that in the third embodiment, the opening 38 (see FIG. 4) is not provided on the side surface of the irradiation port cover 31B.

A decorative cover 72 is detachably attached to the bottom surface of the irradiation port cover 31B. Since the second energy modulation section 42 can be hidden by the decorative cover 72, the appearance of the irradiation port 10B can be improved.

When replacing the second energy modulation section 42, the makeup cover 72 is removed from the irradiation port cover 31B. Then, the second energy modulation section 42 is removed from the opening 71 of the irradiation port cover 31B, and a replacement second energy modulation section 42' is attached. After that, the decorative cover 72 is attached again.

In the third embodiment, when the second energy modulating section 42 is arranged downstream of the first energy modulating section 41 in the traveling direction of the particle beam B, the second energy modulating section 42 is arranged without removing the irradiation port cover 31B. The replacement work of the modulation section 42 can be performed.

(Fourth embodiment)
Next, the irradiation port 10C of the particle beam therapy system 1C of the fourth embodiment will be explained using FIG. The same reference numerals are assigned to the same components as those shown in the above-described embodiment, and overlapping descriptions are omitted.

As shown in FIG. 26 , in the fourth embodiment, the first energy modulating section 41 is fixed to the pedestal 33 . Also, the second energy modulation section 42 is fixed to the pedestal 33 below the first energy modulation section 41 . That is, both the first and second energy modulating sections 41 and 42 are supported by the pedestal 33 . Furthermore, an opening 73 is opened at the bottom of the irradiation port cover 31C. Note that the lower end of the mount 33 is provided at a position corresponding to the opening 73 .

A connecting portion 37 to which the second energy modulating portion 42 is detachably connected is provided at the lower end of the mount 33 . In the fourth embodiment, the lower end of the pedestal 33 serves as the placement portion 47 . The lower end of the mount 33 is set corresponding to the position of the opening 73 of the irradiation port cover 31C. That is, in the fourth embodiment, the opening 73 of the irradiation port cover 31C serves as the position defining portion.

Thus, the second energy modulation section 42 of the fourth embodiment is arranged downstream of the first energy modulation section 41 in the direction in which the particle beam B travels. In addition, in the fourth embodiment, the opening 38 (see FIG. 4) is not provided on the side surface of the irradiation port cover 31C.

Note that the irradiation port cover 31C is supported by the frame 33 via the trunk cover 32. As shown in FIG. A gap is formed between the edge of the opening 73 of the irradiation port cover 31</b>C and the mount 33 .

When replacing the second energy modulating section 42 , the second energy modulating section 42 is removed from the connection section 37 of the mount 33 . Then, the replacement second energy modulation section 42 ′ is attached to the connection section 37 of the mount 33 .

In the fourth embodiment, since the second energy modulation section 42 is supported by the pedestal 33, the second energy modulation section 42 can be firmly supported. In addition, since it becomes easier to access the second energy modulation section 42 from the downstream side in the traveling direction of the particle beam B, the replacement work of the second energy modulation section 42 can be easily performed. Furthermore, when the second energy modulating section 42 is removed, the first energy modulating section 41 can be accessed.

(Fifth embodiment)
Next, the irradiation port 10D of the particle beam therapy system 1D of the fifth embodiment will be explained using FIG. The same reference numerals are assigned to the same components as those shown in the above-described embodiment, and overlapping descriptions are omitted.

As shown in FIG. 27, in the fifth embodiment, the first energy modulator 41 is fixed to the pedestal 33 . Also, the second energy modulation section 42 is detachably attached to the bottom surface of the irradiation port cover 31</b>D via the connection section 37 . That is, the second energy modulation section 42 is provided below the first energy modulation section 41 . In addition, in the fifth embodiment, the surface of the bottom portion of the irradiation port cover 31</b>D serves as the placement portion 47 . Also, the connecting portion 37 of the irradiation port cover 31D serves as a position defining portion.

Thus, the second energy modulation section 42 of the fifth embodiment is arranged downstream of the first energy modulation section 41 in the direction in which the particle beam B travels. In addition, in the fifth embodiment, the opening 38 (see FIG. 4) is not provided on the side surface of the irradiation port cover 31D.

When replacing the second energy modulation section 42, the second energy modulation section 42 is removed from the connection section 37 of the irradiation port cover 31D. Then, the replacement second energy modulation section 42' is attached to the connection section 37 of the irradiation port cover 31D.

In the fifth embodiment, since the second energy modulation section 42 is provided on the surface of the irradiation port cover 31D, replacement work can be easily performed.

(Sixth embodiment)
Next, the irradiation port 10E of the particle beam therapy system 1E of the sixth embodiment will be explained using FIG. The same reference numerals are assigned to the same components as those shown in the above-described embodiment, and overlapping descriptions are omitted.

As shown in FIG. 28, in the sixth embodiment, the first energy modulation section 41E is provided on the rear surface of the bottom of the irradiation port cover 31E. The first energy modulation section 41E is attached to the irradiation port cover 31E by the connecting section 37. As shown in FIG. Also, the second energy modulation section 42 is provided in the guide section 45 above the first energy modulation section 41E. That is, the first energy modulating section 41E is arranged downstream of the second energy modulating section 42 in the direction in which the particle beam B travels.

The first energy modulation section 41E of the sixth embodiment is composed of a porous block made of a porous material. This porous block has a large number of fine cavities formed inside a synthetic resin. In other words, inside the porous block, fine cavities and substances constituting the block are arranged in a mottled manner. The porous block is formed with passages through a small number of cavities and passages through a large number of cavities. In addition, the path|route mentioned here shows the straight line which passes through the 1st energy modulation|alteration part 41E from one surface toward the other surface in an up-down direction.

For example, a particle beam B that has passed through a small number of cavities has its energy attenuated more than a particle beam B that has passed through a large number of cavities. That is, in the body of the patient P, the particle beam B that has passed through a small number of cavities is stopped at a shallower position than the particle beam B that has passed through a large number of cavities. Thus, the energy distribution of the particle beam B can be changed by forming the first energy modulation section 41E from the porous block. Thereby, the Bragg peak of the particle beam B can be widened.

The porous block is set so that the dose of the passing particle beam B exhibits a Gaussian distribution. Also, the thickness dimension T1 of the first energy modulation section 41E made of the porous block is thicker than the thickness dimension T2 of the second energy modulation section 42 made of the ridge filter.

In the sixth embodiment, the first energy modulation section 41E can be manufactured more easily than when the first energy modulation section 41E is formed from a ridge filter by forming the first energy modulation section from a porous material.

In addition, since the thick first energy modulation section 41E is fixed to the irradiation port cover 31E, and the second energy modulation section 42, which is thinner than this, is subject to replacement work, maintainability can be improved.

Although the porous block has a secondary property of scattering the particle beam B, in the sixth embodiment, the position of the first energy modulation unit 41E is the most to the patient P of the irradiation port cover 31E. Since it substantially coincides with the adjacent portion, it is possible to suppress the spread of the particle beam B in the radial direction while widening the Bragg peak of the particle beam B.

(Seventh embodiment)
Next, the irradiation port 10F of the particle beam therapy system 1F of the seventh embodiment will be explained using FIG. The same reference numerals are assigned to the same components as those shown in the above-described embodiment, and overlapping descriptions are omitted.

As shown in FIG. 29, the bottom portion of the irradiation port cover 31F is made of a porous material, and this portion serves as the first energy modulation portion 41F. A bottom portion of the irradiation port cover 31F serves as a position defining portion. Also, the second energy modulation section 42 made up of a ridge filter is provided in the guide section 45 above the first energy modulation section 41F.

In the seventh embodiment, the first energy modulation section 41F is exposed, but since the irradiation port cover 31F and the first energy modulation section 41F are integrated, the portion of the first energy modulation section 41F can be made inconspicuous. can be done. Therefore, the appearance of the irradiation port 10F can be improved.

(Eighth embodiment)
Next, the irradiation port 10G of the particle beam therapy system 1G of the eighth embodiment will be explained using FIG. The same reference numerals are assigned to the same components as those shown in the above-described embodiment, and overlapping descriptions are omitted.

As shown in FIG. 30, in the eighth embodiment, three guide portions 45 are provided inside the irradiation port cover 31G. Each guide portion 45 is provided with a second energy modulation portion 42 . That is, three second energy modulation units 42 are arranged side by side in the vertical direction.

Placement portions 47 are provided corresponding to the respective second energy modulation portions 42 inside the irradiation port cover 31G. These arrangement portions 47 overlap the first energy modulation portion 41 and are positioned to compensate for the widening of the Bragg peak. Further, inside the irradiation port cover 31G, a retraction portion 74, which is a position retracted from the trajectory of the particle beam B, is provided.

By driving the guide portion 45 , the second energy modulation portion 42 is moved between the placement portion 47 and the retraction portion 74 . That is, a plurality of second energy modulation sections 42 can be arranged in advance inside the irradiation port cover 31G, and the second energy modulation section 42 can be changed according to the irradiation target.

A large opening 38 is opened in the side surface of the irradiation port cover 31G. This opening 38 is closed by a lid 39 . By opening the opening 38, the operator can access each second energy modulation section 42. FIG.

Alternatively, the guide portion 45 can be protruded from the opening 38 to replace the second energy modulation portion 42 . In addition, the three second energy modulation sections 42 are moved along the same specific direction by driving the guide section 45 . An opening 38 is formed corresponding to this specific direction.

Moreover, the particle beam B may be irradiated with two or more second energy modulation units 42 arranged in the arrangement unit 47 . Furthermore, the particle beam B may be irradiated while all the second energy modulation sections 42 are retracted to the retraction section 74 .

In the eighth embodiment, a plurality of second energy modulation sections 42 are arranged in advance inside the irradiation port cover 31G, and the second energy modulation section 42 can be changed according to the irradiation target, so maintainability is improved. can be improved.

The particle beam therapy apparatus according to this embodiment has been described based on the first to eighth embodiments, but the configuration applied in any one embodiment may be applied to another embodiment, You may combine the structure applied in each embodiment.

In addition, in the flowchart of the present embodiment, each step is exemplified in a form in which each step is executed in series. good. Also, some steps may be executed in parallel with other steps.

The system of this embodiment includes a dedicated chip, an FPGA (Field Programmable Gate Array), a GPU (Graphics Processing Unit), or a CPU (Central Processing Unit) processor such as a control device highly integrated, ROM (Read Only Memory) or RAM (Random Access Memory), external storage devices such as HDD (Hard Disk Drive) or SSD (Solid State Drive), display devices such as displays, and input devices such as mice or keyboards , and a communication interface. This system can be realized with a hardware configuration using a normal computer.

It should be noted that the program executed by the system of the present embodiment is pre-installed in a ROM or the like and provided. Alternatively, this program can be stored as an installable or executable file on a non-transitory computer-readable storage medium such as CD-ROM, CD-R, memory card, DVD, flexible disk (FD), etc. may be stored and provided.

Also, the program executed by this system may be stored on a computer connected to a network such as the Internet, downloaded via the network, and provided. In addition, this system can also be configured by combining separate modules that independently perform each function of the constituent elements and are interconnected by a network or a dedicated line.

In this embodiment, a facility for heavy ion radiotherapy is exemplified, but this embodiment can also be applied to other facilities. For example, the present embodiment may be applied to facilities that perform proton beam cancer therapy.

The position defining portion of the present embodiment may be the connection portion 37 connecting the energy modulation portions 41 and 42, the opening portions 71 and 73 in which the energy modulation portions 41 and 42 are arranged, or the energy modulation portions 41 and 42. 42 may be indirectly connected to the irradiation port cover 31 via a mounting jig.

Note that the Bragg peak of the particle beam B may be widened by using a plurality of first energy modulation units 41 stacked. Moreover, the Bragg peak of the particle beam B may be widened by using a plurality of second energy modulation units 42 stacked.

Note that the broadening of the Bragg peak of the particle beam B may be performed using only the first energy modulation section 41 without using the second energy modulation section 42 .

The term "access" in this embodiment includes a mode in which the operator can touch the energy modulation section 42 . For example, access includes allowing the operator to touch the energy modulation section 42 without moving the energy modulation section 42 out of the irradiation port cover 31 . The term access also includes aspects that the operator can see in close proximity to the energy modulator 42 .

Although the particle beam therapy system 1 of this embodiment includes the rotating gantry 5, the rotating gantry 5 is not provided, and the particle beam therapy apparatus 1 includes a fixed irradiation chamber in which the irradiation port 10 is fixedly arranged. It may be a therapeutic device.

A frame portion for holding the energy modulating portion 42 may be provided, and the energy modulating portion 42 and the frame portion may constitute a cartridge-type replacement device that can be attached to and detached from the opening 38 . A lid portion 39 that closes the opening portion 38 may be provided integrally with the frame portion, and the lid portion 39 may be detachable from the opening portion 38 together with the frame portion.

In this embodiment, it is determined whether or not the appropriate energy modulators 41 and 42 are arranged based on the identification information stored in the tags 56 and 57. It may be determined whether or not appropriate energy modulation units 41 and 42 are arranged. For example, unevenness having a different shape is provided for each of the energy modulation sections 41 and 42 on the edges of the energy modulation sections 41 and 42, and by reading the shape of the unevenness, it is possible to determine whether the appropriate energy modulation sections 41 and 42 are arranged. You can judge no.

In this embodiment, the particle beam B travels through the vacuum duct D, which has no air, so that the particle beam B is not scattered by the air. A vacuum is not required. For example, inside the vacuum duct D, there may be helium gas that scatters the particle beam B relatively little.

In this embodiment, the lid driving portion 51 for opening and closing the lid portion 39 is provided. Moreover, it is good also as a push type opened by a spring when an operator pushes the cover part 39 by hand.

According to at least one embodiment described above, the energy modulation section is provided corresponding to the portion of the irradiation port cover closest to the patient and widens the Bragg peak of the passing particle beam beam. It is possible to suppress the radial spread of the particle beam while widening the Bragg peak of the beam.

Further, according to at least one embodiment, the second energy modulating portion is movable between a position retracted from the orbit and a position on the orbit overlapping the first energy modulating portion to compensate for broadening of the Bragg peak. Thereby, the work of changing the energy modulation section can be simplified.

Further, according to at least one embodiment, maintenance is improved by providing an opening that is opened in a portion corresponding to a specific direction of the irradiation port cover and that allows access to the energy modulation unit. can.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, changes, and combinations can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, as well as the scope of the invention described in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 1 (1A, 1B, 1C, 1D, 1E, 1F, 1G)... Particle beam therapy apparatus, 2... Beam generator, 3... Circular accelerator, 4... Beam transport line, 5... Rotating gantry, 6... Bending electromagnet, 7 Support roller 8 Drive motor 9 End ring 10 (10A, 10B, 10C, 10D, 10E, 10F, 10G) Irradiation port 11 Scanning electromagnet 12 Treatment space 13 Treatment table 14 Building 15 Treatment room 16 Inner wall 17 Support 18 Reverse-rotating synchronous motor 19 Decorative wall 20a, 20b Track rail 21 Moving floor 22 High-frequency acceleration cavity 23, 24... Bending electromagnet, 25... Quadrupole electromagnet, 30... Beam emitting part, 31 (31A, 31B, 31C, 31D, 31E, 31F, 31G)... Irradiation port cover, 32... Body cover, 33... Base, 34... Dose monitor , 35... Position monitor 36... Range shifter 37... Connection part 38... Opening part 39... Lid part 40... Operation part 41 (41E, 41F)... First energy modulation part 42... Second energy modulation part , 43... Ridge bar, 44 (44a, 44b)... Step portion, 45... Guide part, 46... Movement holding part, 47... Placement part, 48... Latch part, 50... Irradiation control system, 51... Lid driving part, 52... Guide driving unit 53 Latch driving unit 54 Position detection sensor 55 Latch sensor 56 First tag 57 Second tag 58 First tag reading unit 59 Second tag reading unit 60 Notification output unit 61 Setting storage unit 62 Placement determination unit 63 Tag determination unit 64 Irradiation control unit 71 Opening 72 Decorative cover 73 Opening 74 Withdrawal unit 80 Slice surface 81 Irradiation spot 82, 83, 84 Bragg peak 90, 91, 92 Gaussian distribution 93, 94a, 94b Bragg peak 95, 96a, 96b Energy distribution B (B1, B2 ) ... particle beam, D ... vacuum duct, F ... scanning range, G1, G2 ... line of sight direction, J ... rotation axis, K ... affected part, M1 ... vertical dimension of opening, M2 ... horizontal dimension of opening, N1 ... Area of the first energy modulation part, N2... Area of the second energy modulation part, P... Patient, Q1... Range of diseased part in patient's body, Q2... Range in depth direction where Bragg peak occurs, R1... Width of ridge bar Dimensions, R2... height dimension of the step portion, R3... width dimension of the step portion, R4... height dimension of the ridge bar of the first energy modulation portion, R5... height dimension of the ridge bar of the second energy modulation portion, R6, R7 Height dimension of the step portion, R8, R9 Width dimension of the step portion, T1 Thickness dimension of the first energy modulation portion, T2 Thickness dimension of the first energy modulation portion.

Claims (11)

a first energy modulation unit arranged on the trajectory of the particle beam at the time of irradiation with the particle beam and widening a Bragg peak of the passing particle beam;
a second energy modulation section movable between a position retracted from the orbit and a position on the orbit overlapping the first energy modulation section and widening the Bragg peak;
with
The energy distribution generated when the second energy modulation section is used alone does not approximate a Gaussian distribution , and the energy distribution generated by overlapping with the first energy modulation section at the position on the orbit is the above has properties similar to Gaussian distribution ,
Particle therapy equipment. 2. The particle beam therapy system according to claim 1, wherein the first energy modulation section has a property capable of widening the Bragg peak by itself. 3. The particle beam therapy system according to claim 1, wherein the second energy modulation section is arranged upstream of the first energy modulation section in the traveling direction of the particle beam. A scanning electromagnet provided upstream of the first energy modulation unit and the second energy modulation unit and controlling a scanning direction of the particle beam,
The particle beam therapy system according to claim 3, wherein the area of said first energy modulation section is larger than the area of said second energy modulation section. 3. The particle beam therapy system according to claim 1, wherein the second energy modulation section is arranged downstream of the first energy modulation section in the traveling direction of the particle beam. A scanning electromagnet provided upstream of the first energy modulation unit and the second energy modulation unit and controlling a scanning direction of the particle beam,
The particle beam therapy system according to claim 5, wherein the area of said second energy modulation section is larger than the area of said first energy modulation section. The first energy modulation section and the second energy modulation section are composed of ridge filters formed with ridge bars,
The particle beam therapy system according to any one of claims 1 to 6, wherein the height of the ridge bar of the first energy modulation section is lower than the height of the ridge bar of the second energy modulation section. a beam emission unit that emits the particle beam toward a patient;
an irradiation port cover that covers the beam emitting part;
a connection section that detachably connects the first energy modulation section to the irradiation port cover;
The particle beam therapy system according to any one of claims 1 to 7, comprising: a beam emission unit that emits the particle beam toward a patient;
an irradiation port cover that covers the beam emitting part;
a connection section that detachably connects the second energy modulation section to the irradiation port cover;
The particle beam therapy system according to any one of claims 1 to 8, comprising: a beam emission unit that emits the particle beam toward a patient;
an irradiation port cover that covers the beam emitting part;
an opening in the illumination port cover to allow access to the second energy modulator;
The particle beam therapy system according to any one of claims 1 to 9, comprising: an arrangement unit provided on the orbit for arranging the second energy modulation unit;
a guide portion that guides insertion and withdrawal of the second energy modulation portion with respect to the placement portion;
The particle beam therapy system according to any one of claims 1 to 10, comprising:

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