JP2021019985A - Particle beam treatment system - Google Patents

Abstract

To provide a particle beam treatment system capable of efficiently constructing a power supply system from a power source to an electromagnet group of a beam transport line.SOLUTION: A particle beam treatment system 1 includes: electromagnet groups 15 for generating a magnetic field for guiding charged particles from a common beam transport line 7 to individual beam transport lines 8; an accelerator room 21 for storing an accelerator 3, the common beam transport line 7, and the individual beam transport lines 8; a power source 18 provided outside the accelerator room 21 for supplying power to each of a plurality of the electromagnet groups 15 inside the accelerator room 21; a trunk cable 27 for guiding power from the power source 18 to the inside of the accelerator room 21; a supply cable 28 provided in correspondence with each of the plurality of the electromagnet groups 15 for guiding power from the trunk cable 27 to the electromagnet groups 15; and a specification part 30 provided inside the accelerator room 21, in which the supply cable 28 is branched from the trunk cable 27.SELECTED DRAWING: Figure 1

Description

Embodiments of the present invention relate to particle beam therapy systems.

Conventionally, there is a particle beam therapy system that irradiates an affected area (cancer) of a patient with a particle beam to treat the patient. In some such particle beam therapy systems, a plurality of treatment rooms are provided, and the particle beam beam accelerated by the accelerator is guided to each treatment room via a beam transport line that branches in the middle. The beam transport line has an electromagnet group composed of a plurality of electromagnets, and power is supplied from a power source to the electromagnet group corresponding to each treatment room.

Japanese Unexamined Patent Publication No. 2006-34701 Japanese Unexamined Patent Publication No. 2007-268031

The beam transport line is installed inside the radiation controlled area, but the power supply is installed outside the radiation controlled area. When power is supplied from the power source to the electromagnet group of the beam transport line, a through hole is formed in the shielding wall for radiation shielding surrounding the radiation controlled area, and a cable extending from the power source to the electromagnet group through this through hole. Must be laid. With a large number of treatment rooms, it is necessary to form a large number of through holes and lay cables. Therefore, there is a demand for efficiently constructing a power supply system from the power source to the electromagnet group of the beam transport line.

An embodiment of the present invention has been made in consideration of such circumstances, and provides a particle beam therapy system capable of efficiently constructing a power supply system from a power source to an electromagnet group of a beam transport line. The purpose is.

The particle beam therapy system according to the embodiment of the present invention includes an accelerator that accelerates charged particles, a common beam transport line that extends from the accelerator and transports the charged particles accelerated by the accelerator, and a plurality of treatment rooms, respectively. The individual beam transport line for transporting the charged particles from the common beam transport line to the treatment room and the plurality of individual beam transport lines are provided corresponding to each of the charged particles. A group of electromagnets for generating a magnetic field leading from a common beam transport line to the individual beam transport line, an accelerator chamber accommodating the accelerator, the common beam transport line, and the individual beam transport line, and an accelerator chamber provided outside the accelerator chamber. , A power source that supplies power to each of the plurality of electromagnet groups inside the accelerator chamber, a backbone cable that guides the power from the power source to the inside of the accelerator chamber, and each of the plurality of electromagnet groups. A supply cable that guides the power from the trunk cable to the electromagnet group, and a specific portion that is provided inside the accelerator chamber and the supply cable branches from the trunk cable.

An embodiment of the present invention provides a particle beam therapy system capable of efficiently constructing a power supply system from a power source to an electromagnet group of a beam transport line.

The plan view which shows the particle beam therapy system of this embodiment. The block diagram which shows the power source, the switching board, and the electromagnet group. A flowchart showing a design method of a particle beam therapy system. The side view which shows the particle beam therapy system of the modification 1. The block diagram which shows the power supply system of the particle beam therapy system of the modification 2.

Hereinafter, embodiments of the particle beam therapy system will be described in detail with reference to the drawings.

Reference numeral 1 in FIG. 1 is a particle beam therapy system. In this particle beam therapy system 1, a particle beam of charged particles such as carbon ions is irradiated to a lesion tissue (cancer) of a patient as a subject for treatment.

Radiation therapy technology that uses carbon ions as charged particles is also called heavy ion beam cancer treatment technology. With this technology, carbon ions pinpoint the cancer lesion (affected area), and while damaging the cancer lesion, it is possible to minimize damage to normal cells. The particle beam is defined as being heavier than an electron in radiation, and includes a proton beam, a heavy particle beam, and the like. Of these, heavy particle beams are defined as heavier than helium atoms.

Cancer treatment using heavy ion beams has a higher ability to kill cancer lesions than cancer treatments using X-rays, gamma rays, and proton beams. Furthermore, the radiation dose is weak on the surface of the patient's body, and the radiation dose peaks in the cancer lesion. Therefore, the number of irradiations and side effects can be reduced, and the treatment period can be shortened.

As shown in FIG. 1, the particle beam therapy system 1 includes a charged particle source 2 that generates charged particles (for example, carbon ions), an accelerator 3 that accelerates the charged particles into a particle beam, and a charged particle source 2. It is provided with an injector 4 for incident the charged particles generated in the above on the accelerator 3.

The accelerator 3 of the present embodiment exemplifies a ring-shaped synchrotron accelerator. The synchrotron accelerator has a vacuum duct through which charged particles pass. Further, it has a plurality of electromagnets 5 and 6 such as a deflection electromagnet and a quadrupole electromagnet arranged along a vacuum duct. Then, when accelerating the charged particles, energy is given to the low-energy charged particles incident on the accelerator 3 by high-frequency power while increasing the applied strength of the magnetic field. The deflecting electromagnet orbits the charged particles along a circular orbit. Quadrupole electromagnets converge or diverge charged particles.

The charged particles accelerated to a predetermined energy become a particle beam and are taken out from the orbit by an electromagnet 6 for emission, which is an extraction device. Then, this particle beam is transported by the common beam transport line 7. Further, the common beam transport line 7 is branched into a plurality of individual beam transport lines 8 and 9.

In addition, the particle beam therapy system 1 includes a plurality of treatment rooms 10 in which patients to be irradiated with the particle beam are arranged. In the present embodiment, in addition to the existing treatment room 10, a new treatment room 11 can be added in the future. Each of the treatment rooms 10 and 11 is provided with a treatment table 12 on which patients are placed. The treatment rooms 10 and 11 may be provided with a rotating gantry 13 capable of changing the irradiation direction of the particle beam to the patient.

Further, the particle beam therapy system 1 is provided corresponding to each of a common beam transport line 7 extending from the accelerator 3 and transporting charged particles accelerated by the accelerator 3 and a plurality of treatment rooms 10, and shares charged particles in common. It includes an individual beam transport line 8 for transporting from the beam transport line 7 to the treatment room 10. An individual beam transport line 9 corresponding to the additional treatment room 11 is also provided.

The individual beam transport lines 8 and 9 branch off from the common beam transport lines 7 and extend to the corresponding treatment rooms 10 and 11, respectively. The particle beam accelerated by the accelerator 3 is branched from the common beam transport line 7 to the individual beam transport lines 8 and 9, and guided to the corresponding treatment rooms 10 and 11, respectively. Although not shown, the treatment rooms 10 and 11 are provided with an irradiation device for irradiating the affected part of the patient with a particle beam.

Each of the individual beam transport lines 8 and 9 of the present embodiment forms at least one of a horizontal beam course, a vertical beam course, an oblique beam course, and a gantry chamber beam course.

The horizontal beam course is a beam course that irradiates a patient with a particle beam from the horizontal direction. The vertical beam course is a beam course that irradiates a patient with a particle beam from a vertical direction. The oblique beam course is a beam course that irradiates a patient with a particle beam from an oblique direction. The gantry chamber beam course is a beam course in which the rotating gantry 13 is used.

First, the charged particles generated by the charged particle source 2 are incident on the accelerator 3. The charged particles are accelerated to about 70% of the speed of light while orbiting the accelerator 3 about one million times to become a particle beam. Then, the particle beam is guided to the treatment rooms 10 and 11 via the common beam transport lines 7 and the individual beam transport lines 8 and 9.

When carbon ions are used as charged particles, the particle beam loses kinetic energy as it passes through the patient's body, slows down, and receives resistance that is almost inversely proportional to the square of the velocity, resulting in a constant velocity. When it drops to, it stops suddenly. Then, high energy called a Bragg peak is emitted near the stop point of the particle beam. The particle beam therapy system 1 can kill only the lesion tissue while suppressing damage to the normal tissue by aligning the Bragg peak with the position of the lesion tissue (affected portion) of the patient.

In general, treatment is not performed in a plurality of treatment rooms 10 and 11 at the same time. For example, the particle beam generated by the accelerator 3 is controlled so as to be guided to any one of the plurality of treatment rooms 10, 11. Then, while treatment is being performed in one treatment room 10 or 11, work such as preparation for the next treatment is performed in the other treatment rooms 10 and 11.

The accelerator 3, the common beam transport line 7, and the individual beam transport lines 8 and 9 have a vacuum duct (beam pipe) whose inside is evacuated. A particle beam travels inside these vacuum ducts. The vacuum ducts of the accelerator 3, the common beam transport line 7, and the individual beam transport lines 8 and 9 are integrated to form a transport path for guiding the particle beam to the treatment rooms 10 and 11. That is, the vacuum duct is a closed continuous space having a sufficient degree of vacuum for passing the particle beam.

Although not shown, the injector 4 includes a low energy beam transport system (LEBT system), a high frequency quadrupole linear accelerator (RFQ), and a drift tube type linear accelerator. The injector 4 then accelerates the charged particles to an energy level that can be accelerated by the accelerator 3. The accelerator 3 includes a high-frequency acceleration cavity that accelerates charged particles by controlling the frequencies of a magnetic field and an accelerating electric field.

The common beam transport line 7 of the present embodiment includes a plurality of electromagnets 14 that control the particle beam. Further, the individual beam transport lines 8 and 9 include electromagnet groups 15 and 16 that form one unit with a plurality of electromagnets that control the particle beam.

As shown in FIG. 2, the individual beam transport lines 8 and 9 include electromagnet groups 15 and 16 in which a plurality of electromagnets 17 form one unit. These electromagnet groups 15 and 16 are provided corresponding to each of the plurality of individual beam transport lines 8 and 9, and generate a magnetic field that guides charged particles from the common beam transport lines 7 to the individual beam transport lines 8 and 9.

As shown in FIG. 1, the electromagnet groups 15 and 16 of the common beam transport line 7 and the individual beam transport lines 8 and 9, respectively, are arranged so as to surround the outer periphery of the bent portion or the branch portion of the vacuum duct. Various types of electromagnets 17 are used for the electromagnet groups 15 and 16. For example, a quadrupole electromagnet for controlling the convergence and divergence of the particle beam and a deflection electromagnet used for changing the traveling direction of the particle beam are used.

The particle beam therapy system 1 of the present embodiment includes a power source 18 that supplies electric power to each of the plurality of electromagnet groups 15 and 16, and an irradiation control unit 19 that controls the power source 18 and controls the electromagnet group. Be prepared.

As shown in FIG. 1, the particle beam therapy system 1 includes a predetermined building 20. Inside the building 20, an accelerator room 21 accommodating an accelerator 3, a common beam transport line 7, individual beam transport lines 8 and 9, and treatment rooms 10 and 11 is provided. Further, a power supply room 22 for accommodating the power supply 18 is provided. In addition, an examination room 23, a staff room 24, a corridor 26, and the like are also provided.

Further, an anterior chamber 25 is provided between the treatment room 10 and the corridor 26. The anterior chamber 25 may form a part of the treatment chamber 10. The front chamber 25 is also called a positioning chamber, and is provided with an operation panel or the like for operating equipment such as a treatment table 12. When positioning the patient, a technician who operates the operation panel is assigned to the anterior chamber 25.

The power supply 18 is, for example, a switchboard such as a cubicle. In the switchboard, the power receiving equipment that steps down the high-voltage electricity sent from the power plant through the substation is housed in a metal box.

The building 20 is a robust building made of reinforced concrete or the like. FIG. 1 illustrates a building 20 in which the accelerator 3, the common beam transport line 7, the individual beam transport lines 8 and 9, and the treatment rooms 10 and 11 are installed on the same floor.

Further, electric power is supplied from the power source 18 to the electromagnet groups 15 and 16 via predetermined cables 27, 28 and 29. To help understanding, only the cables 27, 28, and 29 that supply power to the electromagnet groups 15 and 16 of the individual beam transport lines 8 and 9 are shown, and the common beam with the electromagnets 5 and 6 of the accelerator 3 is shown. Illustration of a cable for supplying electric power from the power source 18 to each of the electromagnet 14 of the transportation line 7 is omitted.

The particle beam therapy system 1 of the present embodiment includes a backbone cable 27 that guides electric power from the power source 18 to the inside of the accelerator chamber 21, and supply cables 28 and 29 that guide electric power from the backbone cable 27 to the existing electromagnet groups 15 and 16. A switching board 30 is provided as a specific portion in which the supply cables 28 and 29 branch from the main cable 27.

A supply cable 28 connected to the existing electromagnet group 15 and a supply cable 29 connected to the additional electromagnet group 16 are provided. These are connected to the switching board 30.

As shown in FIG. 1, a power supply 18 is provided inside the power supply room 22, and one trunk cable 27 extends from the power supply room 22 to the accelerator room 21. In order to pass the trunk cable 27, one through hole 32 is provided in the shielding wall 31 that separates the power supply room 22 and the accelerator room 21.

The supply cable 28 inside the accelerator chamber 21 is provided corresponding to each of the plurality of electromagnet groups 15. For example, if there are four individual beam transport lines 8, four supply cables 28 are provided corresponding to each. Then, the upstream end of the supply cable 28 is connected to the switching board 30.

In the present embodiment, a power supply system 33 in which a plurality of supply cables 28 and 29 are branched from one trunk cable 27 is formed (see FIG. 2). The switching board 30 is the first branch of the power supply system 33 that branches from the power supply 18 at the base end to the plurality of electromagnet groups 15 and 16 at the ends. In this way, the wiring work of the supply cables 28 and 29 on the downstream side of the switching board 30 can be efficiently performed at the time of construction or maintenance of the particle beam therapy system 1.

The switching board 30 is provided inside the accelerator chamber 21. That is, the switching board 30 is provided in the vicinity of the electromagnet groups 15 and 16. The term “neighborhood” indicates a position closer than the power supply 18.

The switching board 30 is controlled by the irradiation control unit 19 to switch the electromagnet groups 15 and 16 to which power is supplied. The irradiation control unit 19 and the switching panel 30 are connected by a control signal line 34.

The irradiation control unit 19 controls the switching board 30 so that electric power is supplied to the electromagnet groups 15 and 16 corresponding to the treatment rooms 10 and 11 that irradiate the particle beam. That is, the electromagnet groups 15 and 16 excited by the irradiation control unit 19 are controlled.

Further, the switching board 30 is covered with a shielding member 35 that shields radiation. The shielding member 35 has a box shape formed of, for example, a member such as iron or lead. By doing so, the irradiation of the switching board 30 with radiation can be suppressed, and the adverse effect of the radiation on the switching board 30 can be suppressed.

At the time of construction of the particle beam therapy system 1, an operator enters the accelerator chamber 21 to perform a predetermined operation. At this time, since the switching board 30 that allows the supply cable 28 to be easily attached and detached is arranged inside the accelerator chamber 21, the supply cable 28 can be laid efficiently. In addition, the expansion work of the treatment room 11 can be efficiently performed.

The accelerator room 21 is a radiation controlled area. The interior of the building 20 is divided into this radiation controlled area and the other normal area (uncontrolled area). The radiation control area is an area provided to clearly classify places where the radiation dose is above a certain level and prevent unnecessary entry of people in order to prevent unnecessary exposure of radiation. The establishment of this radiation controlled area is stipulated by law.

The charged particle source 2, the injector 4, the electromagnets 5 and 6 of the accelerator 3, the electromagnet 14 of the common beam transport line 7, and the electromagnet groups 15 and 16 of the individual beam transport lines 8 and 9 are devices that emit radiation during operation. Therefore, it is provided in the radiation controlled area.

The building 20 surrounds the accelerator room 21, which is a radiation controlled area, and includes a shielding wall 31 as a shielding structure portion that shields radiation. That is, the radiation controlled area is partitioned by a shielding wall 31 around it. In addition, the normal area is partitioned by normal walls 36 and 37, which are not supposed to shield radiation.

The shielding wall 31 prevents radiation from leaking to the outside of the radiation controlled area. The thickness T of the shielding wall 31 is 1 to 2 m or more. When a metal plate such as lead or iron is provided inside the shielding wall 31, the thickness T of the shielding wall 31 may be less than 1 m.

Further, the ceiling portion of the accelerator chamber 21, which is a radiation controlled area, is covered with a shielding ceiling plate as a shielding structure portion having a predetermined thickness and formed of concrete. The floor portion of the accelerator chamber 21 is covered with a shielding floor formed of concrete as a shielding structure portion having a predetermined thickness.

Radiation is mainly generated at the deflection part and the stop part (disappearing part) of the beam, and is generated in the tangential direction especially at the time of beam deflection. Therefore, when the accelerator 3, the common beam transport line 7, and the individual beam transport lines 8 and 9 are arranged horizontally side by side, it is preferable to have a structure having sufficient shielding ability in the horizontal direction. For example, the shielding wall 31 has a large shielding ability as compared with the ceiling plate.

Inside the building 20, facilities such as an examination room 23, a staff room 24, and a corridor 26 are provided in a normal area. The entry path for people from the normal area to the treatment rooms 10 and 11 is formed by a shielding wall 31 and formed in a crank shape bent in a plan view. Therefore, radiation does not leak from the treatment rooms 10 and 11 toward the normal area.

Further, since the power supply 18 is provided in the power supply room 22 outside the accelerator room 21, it is not affected by radiation even when the particle beam therapy system 1 is in operation. Therefore, it is easy for the operator to perform maintenance on the power supply 18.

A large budget is required to construct the particle beam therapy system 1. Therefore, when the particle beam therapy system 1 is newly installed, the number of facilities such as the treatment room 10 is reduced in order to reduce the initial cost. Then, a few years after the start of operation, expansion work will be carried out when the management is stable, and the number of facilities will be increased. In the present embodiment, a place for expanding the treatment room 11 in which the rotating gantry 13 is arranged is secured in advance inside the accelerator room 21.

When constructing the particle beam therapy system 1, it is possible to reduce the number of installations of the rotating gantry 13, which is the most costly device, to reduce the cost at the time of new installation, and then add the rotating gantry 13 to improve the operating rate. it can.

The rotary gantry 13 is a large-sized device having a cylindrical shape. The rotating gantry 13 is installed so that the central axis of the cylinder faces the horizontal direction. The rotary gantry 13 can rotate around this axis. A vacuum duct and an electromagnet group extended from the individual beam transport line 9 are attached to the rotating gantry 13. In the rotary gantry 13, the vacuum duct is first guided along the central axis of the rotary gantry 13, extends once toward the outer peripheral side of the cylinder of the rotary gantry 13, and then extends again toward the inner peripheral side of the rotary gantry 13. ..

The rotating gantry 13 is provided with an irradiation unit that irradiates the patient with a particle beam guided by the individual beam transport line 9. This particle beam can be scanned from the irradiation unit in two directions orthogonal to the beam traveling direction. The patient is placed on a treatment table provided inside the rotating gantry 13. This treatment table can be moved with the patient on it. By moving the treatment table, the patient can be moved to the irradiation position of the particle beam and aligned. Therefore, the particle beam can be irradiated to the lesion tissue of the patient with the optimum accuracy.

Further, by rotating the rotating gantry 13, the irradiation unit can be rotated around the patient. Then, the particle beam can be irradiated from any direction around the patient. That is, the rotating gantry 13 is a device capable of changing the irradiation direction of the charged particles guided by the individual beam transport line 9 to the patient. Therefore, it is possible to accurately irradiate the affected area with the particle beam from the optimum direction while reducing the burden on the patient.

In this embodiment, the rotary gantry 13 is provided in the additional treatment room 11, but other embodiments may be used. For example, the existing treatment room 10 may be provided with the rotating gantry 13 corresponding to the gantry room beam course. Then, the additional treatment room 11 may correspond to another beam course.

When the treatment room 11 is expanded, an individual beam transport line 9, an electromagnet group 16, and a supply cable 29 for expansion corresponding to the treatment room 11 are provided. A supply cable 29 for expansion can be connected to the switching board 30. In this way, when the treatment room 11 is expanded, the expansion work including the construction of the power supply system 33 can be efficiently performed.

As shown in FIG. 2, the switching board 30 includes a plurality of contactors 38 and 39 to which the supply cables 28 and 29 can be connected. The contactors 38 and 39 are also referred to as electromagnetic switches. Supply cables 28 and 29 are attached to and detached from the contactors 38 and 39. These contactors 38 and 39 control ON / OFF of power supply to the respective supply cables 28 and 29.

The switching board 30 of the present embodiment includes a contactor 38 corresponding to the existing supply cable 28 and a contactor 39 corresponding to the uninstalled supply cable 29. That is, a contactor 39 to which the supply cable 29 newly added when the treatment room 11 is added is connected is provided in advance. In this way, when the treatment room 11 is expanded, it is not necessary to replace the switching board 30, so that the expansion work can be efficiently performed. Further, since the existing power supply 18 can be used for the treatment room 11 for expansion, it is not necessary to add a new power supply 18. Further, it is not necessary to newly add a through hole 32 to the shielding wall 31. Therefore, no modification to the building 20 is required.

In the present embodiment, the switching board 30 includes a contactor 39 corresponding to the supply cable 29 which is not provided, but other embodiments may be used. For example, the switching board 30 may be provided with a contactor 38 corresponding to the existing supply cable 28, and a contactor 39 for expansion may be newly added when the treatment room 11 is expanded.

As shown in FIG. 1, the distances from the switching board 30 to the plurality of electromagnet groups 15 and 16 are different from each other. However, the plurality of supply cables 28 and 29 of the present embodiment are adjusted so that the lengths from the switching board 30 to the electromagnet groups 15 and 16 are the same. For example, the length of the other supply cable 28 is set according to the length of the longest supply cable 29 among all the supply cables 28 and 29. In the present embodiment, since the distance from the switching board 30 to the electromagnet group 16 for expansion is the longest, the supply cable 29 for expansion is the longest. When the total length of the supply cable 28 is longer than the distance from the switching board 30 to the electromagnet group 15, a winding portion 28a is formed by winding a part of the supply cable 28, and the laying distance thereof is adjusted. ..

By making the lengths of all the supply cables 28 and 29 the same, the electrical resistance of the respective supply cables 28 and 29 becomes the same. Therefore, it becomes easy to control the electric power supplied to each of the electromagnet groups 15 and 16. That is, the gain adjustment work of the power supply 18 becomes unnecessary.

Further, the length of the supply cable 29 of the individual beam transport line 9 corresponding to the additional treatment room 11 can be set in advance. The length of the other supply cable 28 is set according to the length of the longest supply cable 29 among all the supply cables 28, 29 including the supply cable 29 for expansion. By doing so, even if the treatment room 11 is added, the electric resistances of the respective supply cables 28 and 29 are the same, so that it becomes easy to control the electric power supplied to the respective electromagnet group 16.

A plurality of supply cables 28 and 29 are branched from the trunk cable 27. In this way, the number of through holes 32 formed in the shielding wall 31 for passing the trunk cable 27 can be reduced. In the present embodiment, since there is only one trunk cable 27, only one through hole 32 is formed in the shielding wall 31.

Conventionally, in a general particle beam therapy system, an electromagnet group 15 and a power supply 18 are paired and connected to each other by an independent supply cable 28. Therefore, when a plurality of treatment rooms 10 are provided, it is necessary to provide a plurality of through holes 32 in the shielding wall 31. Further, the increase of the through holes 32 also affects the radiation shielding design, and it is necessary to increase the wall thickness according to the shielding calculation result. As the burden of work on the building side increases, the construction work will take longer.

Further, it is necessary to secure a space for arranging a plurality of power supplies 18 in the limited floor area of the building 20. In addition, the quantity of the supply cable 28 used also increases in proportion to the increase in the treatment room 10. Further, as the number of treatment rooms 10 increases, the number of supply cables 28 increases, which hinders the access of workers and the arrangement space of equipment. Furthermore, the laying work will also increase.

In the particle beam therapy system 1 of the present embodiment, since power can be supplied from one power source 18 to a plurality of electromagnet groups 15 and 16, the number of power sources 18 can be reduced. Further, the space required for arranging the power supply 18 can be reduced. Further, since the switching board 30 as a specific unit is provided inside the accelerator chamber 21, the work of laying the supply cables 28 and 29 can be efficiently performed.

Further, in the particle beam therapy system 1, since the switching board 30 is provided inside the accelerator chamber 21, the quantity of the supply cable 28 is reduced, the number of through holes 32 of the shielding wall 31 is reduced, and the treatment chamber 11 is expanded. It is possible to reduce the number of repair items.

With the advancement of beam optical calculation technology, it has become possible to optimize optical calculation such that different electromagnets are excited with the same current value and beams having the same beam properties are transported to different treatment rooms 10 and 11. In the particle beam therapy system 1, the electromagnet groups 15 and 16 are arranged corresponding to the treatment rooms 10 and 11 in which the beam optical parameters are optimized and standardized. By arranging the switching board 30 in the vicinity of these electromagnet groups 15 and 16, the supply cables 28 and 29 from the switching board 30 to the electromagnet groups 15 and 16 can be shortened, and the lengths thereof can be easily made uniform. Become.

In the particle beam therapy system 1, the lengths of the supply cables 28 and 29 can be easily aligned, so that the construction period itself can be shortened and the space of the power supply room 22 can be reduced. Further, it leads to cost reduction of the particle beam therapy system 1. In addition, the number of cables between the accelerator chamber 21 in the radiation controlled area and the power supply chamber 22 in the normal area is dramatically reduced, and the number of through holes 32 can be reduced accordingly. Further, the size of the through hole 32 itself can be reduced. Thereby, the radiation shielding effect can be improved. Therefore, a through hole 32 can be formed in the vicinity of the radiation source.

In the particle beam therapy system 1, the number of cable trays in which the trunk cable 27 and the supply cable 28 are arranged can be reduced. Further, the degree of freedom in arranging the electromagnet group 15 with respect to the building 20 can be increased. As described above, the particle beam therapy system 1 enables a device design that is easy to meet the user's request while being a popular machine. Further, by optimizing the supply cable 28 to facilitate the switching operation, the treatment time can be shortened and the burden on the patient can be reduced.

In addition, each of the individual beam transport lines 8 and 9 forms at least one of a horizontal beam course, a vertical beam course, an oblique beam course, and a gantry chamber beam course. In this way, even if the individual beam transport lines 8 and 9 are provided corresponding to various types of beam courses, the trunk cable 27 is commonly used, so that the power supply system 33 can be easily constructed. Become.

In the present embodiment, the locations where radiation leaks from the accelerator 3, the common beam transport lines 7, and the individual beam transport lines 8 and 9 during operation are specified in advance. Then, the switching board 30 is arranged so as to avoid a place where radiation leaks.

In this way, the structure for protecting the switching board 30 from radiation can be simplified. For example, the thickness of the shielding member 35 can be reduced or simplified. The location where the radiation leaks is specified by simulation. The simulation also includes the implementation of radiation shielding calculations.

Further, the distribution of the dose based on the radiation leaking from the accelerator 3, the common beam transport line 7, and the individual beam transport lines 8 and 9 during operation is specified in advance. Then, the switching board 30 is arranged at a place where the dose is equal to or less than a predetermined threshold value.

By doing so, it becomes possible to increase the choices of places where the switching board 30 can be arranged, the irradiation of radiation to the switching board 30 is suppressed, and the switching board 30 is arranged at a position close to the electromagnet groups 15 and 16. be able to. The dose distribution is obtained by simulation. Further, the threshold value may be a value preset by the designer of the particle beam therapy system 1 or may be an average value of the dose inside the accelerator chamber 21. Then, the switching board 30 is provided at a place where the dose is low.

As described above, in the present embodiment, the switching board 30 is covered with the shielding member 35, and together with the execution of the shielding calculation, the switching board 30 is specified as a low-dose region where the switching board 30 can be arranged, and is in the vicinity of the electromagnet groups 15 and 16. Set the optimum position.

Next, the design method of the particle beam therapy system 1 will be described with reference to the flowchart of FIG. It should be noted that the above-mentioned FIGS. 1 to 2 are referred to as appropriate.

As shown in FIG. 3, first, in step S11, the designer performs the basic design of the particle beam therapy system 1. Here, the arrangement mode of the accelerator 3, the common beam transport line 7, and the individual beam transport lines 8 and 9 inside the accelerator chamber 21 is determined. In addition to the existing treatment room 10, the setting including the treatment room 11 for expansion is performed. Further, based on the beam optical calculation, the electromagnet groups 15 and 16 capable of sharing the power supply 18 will be examined.

In the next step S12, the designer simulates the radiation leaking from the accelerator 3, the common beam transport line 7, and the individual beam transport lines 8 and 9 during operation. In addition, identify the location of radiation leakage and the dose distribution.

In the next step S13, the designer sets the arrangement of the switching board 30 to a place where the radiation leakage portion can be avoided. Further, the arrangement of the switching board 30 is set at a place where the dose is equal to or less than a predetermined threshold value. That is, the design is performed so that the switching board 30 is arranged at a position avoiding the high dose region. In addition, the shielding structure of the switching board 30 will be examined, and a design will be made to reduce the influence of radiation.

In the next step S14, if the designer sets the lengths of the respective supply cables 28 and 29 corresponding to the distances from the switching board 30 to the plurality of electromagnet groups 15 and 16, the designer can use them for expansion. The length of the longest supply cable 29 among all the supply cables 28 and 29 including the supply cable 29 is specified.

In the next step S15, the designer sets the length of the other supply cable 28 according to the length of the longest supply cable 29 in the case of the above-mentioned temporary setting. That is, the lengths of the supply cables 28 and 29 are determined so that the lengths of the supply cables 28 and 29 are the same.

In the next step S16, the designer performs the final design of the particle beam therapy system 1. Here, the final design of the building 20, the confirmation of the overall feasibility of the particle beam therapy system 1, and the optimization design are performed. Then, this design method is completed.

Although the flowchart of the present embodiment illustrates a mode in which each step is executed in series, the context of each step is not necessarily fixed, and even if the context of some steps is exchanged. good. Also, some steps may be executed in parallel with other steps.

Next, a modified example will be described. FIG. 4 is a side view showing the particle beam therapy system 1A of the modified example 1. The particle beam therapy system 1A of the first modification includes a two-story building 40. The first floor of the building 40 is the accelerator room 21, and the second floor is the power supply room 22.

The accelerator chamber 21, which is a radiation controlled area, is surrounded by a shielding wall 41 as a shielding structure portion. Further, the ceiling portion of the accelerator chamber 21 and the floor portion of the power supply chamber 22 are covered with a shielding floor 42 as a shielding structure portion. The floor portion of the accelerator chamber 21 is also covered with the shielding floor 43 as the shielding structure portion.

The power supply room 22, which is a normal area, is surrounded by a normal wall 44, which is not supposed to shield radiation. Further, the ceiling portion of the power supply room 22 is also a ceiling plate 45 that is not supposed to shield radiation.

A power supply 18 is provided inside the power supply room 22. Further, inside the accelerator chamber 21, a switching board 30 and a plurality of electromagnet groups 15 are provided. Further, one through hole 46 is provided in the shielding floor 42 that separates the accelerator chamber 21 and the power supply chamber 22. A trunk cable 47 extends from the power supply room 22 to the accelerator room 21 through the through hole 46. The power supply 18 and the switching board 30 are connected by the trunk cable 47. Then, a plurality of supply cables 48 extend from the switching board 30. Each supply cable 48 is connected to the corresponding electromagnet group 15.

In this way, the accelerator chamber 21 and the power supply chamber 22 may be provided on different layers, and the through hole 46 may be provided in the shielding floor 42. When constructing the particle beam therapy system 1A, the number of trunk cables 47 connecting the accelerator chamber 21 and the power supply chamber 22 having different layers can be reduced, so that the construction work can be efficiently performed.

FIG. 5 is a configuration diagram showing a power supply system 49 of the particle beam therapy system 1B of the second modification. In this modification 2, the accelerator chamber 21 and the power supply chamber 22 are separated by a shielding wall 31.

Inside the power supply room 22, one power supply 18 and an irradiation control unit 19 are provided. Inside the accelerator chamber 21, eight electromagnet groups 50, two switching boards 51, and one distribution board 52 are provided.

The power supply 18 is connected to the distribution board 52 via one trunk cable 53. The trunk cable 53 is led from the power supply 18 to the inside of the accelerator chamber through the through hole 32. Then, two first supply cables 54 extend from the distribution board 52, and each of them is connected to the switching board 51. Further, four second supply cables 55 extend from one switching board 51, and each of them is connected to the electromagnet group 50. The distribution board 52 of the modified example 2 may have a function as a switching board.

In the second modification, the distribution board 52, which is the first branching portion of the power supply system 49 that branches from one power supply 18 to the plurality of electromagnet groups 50, is a specific portion. By doing so, since the first supply cable 54 and the second supply cable 55 are arranged in the accelerator chamber 21, the wiring work can be efficiently performed.

In this embodiment, a human patient is illustrated as a subject, but other embodiments may be used. For example, when animals such as dogs and cats are used as subjects and radiation therapy is performed on these animals, the particle beam therapy system 1 may be used.

In the present embodiment, the synchrotron accelerator is illustrated as the accelerator 3, but other embodiments may be used. For example, the accelerator 3 may be another circular accelerator or a linear linear accelerator.

In the present embodiment, the lengths of all the supply cables 28 and 29 are the same, but other modes may be used. For example, the lengths of the respective supply cables 28 and 29 may be different.

In the present embodiment, since the supply cable 29 for expansion is the longest, the lengths of the other supply cables 28 are determined according to the supply cable 29, but it is another embodiment. Is also good. For example, if any one of the existing supply cables 28 is the longest, the other existing supply cables 28 and the expansion can be made according to the length of the longest supply cable 28. The length of the supply cable 29 may be determined.

According to the embodiment described above, a power supply system from the power source to the electromagnet group of the beam transport line is constructed by providing a specific portion provided inside the accelerator chamber and branching the supply cable from the trunk cable. It can be done efficiently.

Although some embodiments of the present invention have been described, these embodiments are presented as examples 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 gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, as well as in the scope of the invention described in the claims and the equivalent scope thereof.

1 (1A, 1B) ... particle beam therapy system, 2 ... charged particle source, 3 ... accelerator, 4 ... incidenter, 5, 6 ... electromagnet, 7 ... common beam transport line, 8 ... individual beam transport line, 9 ... expansion Individual beam transport line for 10 ... treatment room, 11 ... treatment room for expansion, 12 ... treatment table, 13 ... rotating gantry, 14 ... electromagnet, 15 ... electromagnet group, 16 ... electromagnet group for expansion, 17 ... electromagnet , 18 ... Power supply, 19 ... Irradiation control unit, 20 ... Building, 21 ... Accelerator room, 22 ... Power supply room, 23 ... Examination room, 24 ... Staff room, 25 ... Front room, 26 ... Corridor, 27 ... Trunk cable, 28 ... Supply cable, 28a ... Winding part, 29 ... Supply cable for expansion, 30 ... Switching board, 31 ... Shielding wall, 32 ... Through hole, 33 ... Power supply system, 34 ... Control signal line, 35 ... Shielding member, 36, 37 ... normal wall, 38 ... contactor, 39 ... extension contactor, 40 ... building, 41 ... shield wall, 42, 43 ... shield floor, 44 ... normal wall, 45 ... ceiling board, 46 ... through hole, 47 ... backbone cable, 48 ... supply cable, 49 ... power supply system, 50 ... electromagnet group, 51 ... switching board, 52 ... distribution board, 53 ... backbone cable, 54 ... first supply cable, 55 ... second supply cable.

Claims (12)

An accelerator that accelerates charged particles,
A common beam transport line that extends from the accelerator and transports the charged particles accelerated by the accelerator.
An individual beam transport line that is provided corresponding to each of the plurality of treatment rooms and transports the charged particles from the common beam transport line to the treatment room.
A group of electromagnets that are provided corresponding to each of the plurality of individual beam transport lines and generate a magnetic field that guides the charged particles from the common beam transport line to the individual beam transport lines.
An accelerator chamber accommodating the accelerator, the common beam transport line, and the individual beam transport lines.
A power source provided outside the accelerator chamber and supplying electric power to each of the plurality of electromagnet groups inside the accelerator chamber.
A backbone cable that guides the electric power from the power source to the inside of the accelerator chamber,
A supply cable provided corresponding to each of the plurality of electromagnet groups and guiding the electric power from the main cable to the electromagnet group.
A specific portion provided inside the accelerator chamber from which the supply cable branches from the trunk cable, and
To prepare
Particle beam therapy system. The specific part is the first branch part of the power supply system that branches from the power source to the plurality of electromagnet groups.
The particle beam therapy system according to claim 1. An irradiation control unit that controls the power supply and controls the electromagnet group is provided.
The specific unit is a switching board controlled by the irradiation control unit to switch the electromagnet group to which the electric power is supplied.
The particle beam therapy system according to claim 1 or 2. A shielding member that covers the switching board and shields radiation is provided.
The particle beam therapy system according to claim 3. The location where radiation leaks from the accelerator, the common beam transport line, and the individual beam transport line during operation has been identified in advance.
The switching board is arranged so as to avoid the place where the radiation leaks.
The particle beam therapy system according to claim 3 or 4. The distribution of radiation-based doses leaking from the accelerator, the common beam transport line, and the individual beam transport lines during operation has been identified in advance.
The switching board is arranged at a position where the dose is below a predetermined threshold value.
The particle beam therapy system according to any one of claims 3 to 5. The treatment room can be expanded,
The switching board can be connected to the supply cable of the individual beam transport line corresponding to the treatment room for expansion.
The particle beam therapy system according to any one of claims 3 to 6. The switching board includes the contactor corresponding to the existing supply cable and the contactor corresponding to the uninstalled supply cable.
The particle beam therapy system according to any one of claims 3 to 7. The plurality of supply cables have the same length from the specific portion to the electromagnet group.
The particle beam therapy system according to any one of claims 1 to 8. The treatment room can be expanded,
The length of the supply cable of the individual beam transport line corresponding to the treatment room for expansion can be preset.
The length of the other supply cable is set according to the length of the longest supply cable among all the supply cables.
The particle beam therapy system according to claim 9. The accelerator chamber is a radiation controlled area, and includes a shielding structure that surrounds the accelerator chamber and shields radiation.
The particle beam therapy system according to any one of claims 1 to 10. The individual beam transport line
A horizontal beam course that irradiates the subject with the charged particles from the horizontal direction,
A vertical beam course that irradiates the charged particles from the direction perpendicular to the subject,
An oblique beam course that irradiates the subject with the charged particles from an oblique direction,
A gantry chamber beam course using a rotating gantry that can change the irradiation direction of the charged particles on the subject,
Form at least one of the beam courses,
The particle beam therapy system according to any one of claims 1 to 11.

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