CN213159020U

CN213159020U - Neutron capture therapy system

Info

Publication number: CN213159020U
Application number: CN202020339782.2U
Authority: CN
Inventors: 陈韦霖; 伍盛煜
Original assignee: China Boron Xiamen Medical Equipment Co ltd
Current assignee: China Boron Xiamen Medical Equipment Co ltd
Priority date: 2020-03-18
Filing date: 2020-03-18
Publication date: 2021-05-11
Anticipated expiration: 2030-03-18

Abstract

The utility model provides a neutron capture treatment system, can avoid or reduce the neutron that causes in the place that shielding wall or floor are passed by subassembly or component and other radiant ray leak. The utility model discloses a neutron capture treatment system, including accelerator, beam transmission portion, neutron beam generation portion, neutron capture treatment system is still including holding the shielding wall of accelerator, beam transmission portion, neutron beam generation portion shield wall towards one side on beam transmission direction upper reaches by beam transmission portion or the position that neutron beam generation portion passed sets up the shielding body, the shielding body is mobilizable and has first position and second position first position forms the accommodation hole that beam transmission portion passed the second position, the accommodation hole is opened.

Description

Neutron capture therapy system

Technical Field

The utility model relates to a radiation irradiation system especially relates to a neutron capture treatment system.

Background

With the development of atomic science, radiation therapy such as cobalt sixty, linacs, electron beams, etc. has become one of the main means of cancer treatment. However, the traditional photon or electron therapy is limited by the physical conditions of the radiation, and can kill tumor cells and damage a large amount of normal tissues in the beam path; in addition, due to the difference in the sensitivity of tumor cells to radiation, conventional radiotherapy is often ineffective in treating malignant tumors with relatively high radiation resistance, such as multiple glioblastoma multiforme (glioblastoma multiforme) and melanoma (melanoma).

In order to reduce the radiation damage of normal tissues around tumor, the target therapy concept in chemotherapy (chemotherapy) is applied to radiotherapy; for tumor cells with high radiation resistance, radiation sources with high Relative Biological Effect (RBE) are also actively developed, such as proton therapy, heavy particle therapy, neutron capture therapy, etc. Wherein, the neutron capture treatment combines the two concepts, such as boron neutron capture treatment, and provides better cancer treatment selection than the traditional radioactive rays by the specific accumulation of boron-containing drugs in tumor cells and the precise neutron beam regulation.

Various radioactive rays are generated in the radiation therapy process, for example, the boron neutron capture therapy process generates neutrons and photons with low energy and high energy, and the radioactive rays can cause damage to normal tissues of a human body to different degrees. Therefore, in the field of radiation therapy, it is an extremely important issue to reduce the radiation contamination to the external environment, medical staff or normal tissues of a patient while achieving effective treatment.

Therefore, a new technical solution is needed to solve the above problems.

SUMMERY OF THE UTILITY MODEL

In order to solve the above problems, the present invention provides a neutron capture treatment system, including an accelerator, a beam transmission unit, a neutron beam generation unit, wherein the accelerator accelerates charged particles to generate a charged particle beam, the beam transmission unit transmits the charged particle beam generated by the accelerator to the neutron beam generation unit, the neutron beam generation unit generates a neutron beam for treatment, the neutron capture treatment system further includes a shielding wall for accommodating the accelerator, the beam transmission unit, and the neutron beam generation unit, a shielding body is disposed at a position where the beam transmission unit or the neutron beam generation unit passes on one side of the shielding wall facing the beam transmission direction upstream, the shielding body is movable and has a first position and a second position, in the first position, an accommodating hole through which the beam transmission unit passes is formed, and in the second position, the accommodation hole is opened. The shield is movable and has a position in which the receiving aperture is open to facilitate movement of the non-movable components providing the operating space without interference with the beam delivery portion.

Preferably, the neutron capture therapy system further comprises a charged particle beam generation chamber and an irradiation chamber, the charged particle beam generation chamber accommodates the accelerator and at least part of the beam transport part, the patient is treated by neutron beam irradiation in the irradiation chamber, the shielding wall comprises a partition wall of the irradiation chamber and the charged particle beam generation chamber, at least part of the neutron beam generation part is embedded in the partition wall, in the first position, the end part of the neutron beam generation part facing the accelerator is covered, recoil neutrons are shielded, a high neutron dose area is limited, an accelerator assembly is protected, irradiation damage of the assembly is reduced, element activation of the accelerator assembly is reduced, and meanwhile, when one irradiation chamber runs, the other irradiation chamber is protected, and the radiation dose of the non-running irradiation chamber is ensured to be at a safe level; in the second position, the end of the neutron beam generating part facing the accelerator is at least partially exposed, providing an operating space, allowing the neutron beam generating part, such as a target or beam shaper, a cooling tube as described below, to be replaced when the accelerator is closed, allowing room for the removal of a portion of the beam transport part during replacement, or allowing the beam transport part to be installed, debugged, and maintained through the partition wall and the shield.

Further, the beam transport section includes a first transport section connected to the accelerator, a beam direction switch that switches a traveling direction of the charged particle beam, and a second transport section that transports the charged particle beam to the neutron beam generating section, the second transport section passing through the first shield to reach the neutron beam generating section, and the accommodation hole accommodates the second transport section.

Furthermore, one side of the partition wall close to the irradiation chamber is provided with an accommodating groove which at least partially accommodates the neutron beam generating part and a supporting module for supporting the neutron beam generating part, and the supporting structure is modularized, so that the neutron beam generating part can be locally adjusted, the precision requirement is met, and the beam quality is improved. And a groove for the beam transmission part to pass through is arranged at one side close to the charged particle beam generating chamber, the accommodating groove and the groove penetrate through the partition wall in the neutron line transmission direction, and the cross section profiles of the neutron beam generating part and the support module thereof are positioned between the accommodating groove and the cross section profile of the groove on a plane perpendicular to the neutron line transmission direction, so that a through seam is avoided in the beam transmission direction, the radiation is further reduced, and the support module is convenient to adjust.

As another preferred mode, the shielding body includes a first shielding portion and a second shielding portion, the first shielding portion and the second shielding portion move to the first position along a first direction and a second direction close to the neutron beam generating portion, respectively, the first shielding portion and the second shielding portion have a first groove and a second groove, respectively, and the first groove and the second groove form the accommodating hole together at the first position.

Further, the first shielding part and the second shielding part slide along a guide rail which is fixed on one side of the shielding wall facing the upstream of the beam transmission direction and extends in a direction parallel to the ground.

Further, the materials of the first shielding part and the second shielding part comprise neutron shielding materials, and the materials of the first shielding part and the second shielding part are boron-containing PE or barite concrete or lead.

As another preferable mode, the neutron beam generating unit further includes a treatment table, the target is disposed between the beam transmitting unit and the beam shaping unit, the charged particle beam generated by the accelerator is irradiated to the target through the beam transmitting unit and reacts with the target to generate neutrons, and the generated neutrons pass through the beam shaping unit and the collimator in sequence to form a neutron beam for treatment and irradiate a patient on the treatment table.

Further, the beam shaper comprises a reflector, a retarder, a thermal neutron absorber, a radiation shield and a beam outlet, wherein the retarder decelerates neutrons generated from the target to a super-thermal neutron energy region, the reflector surrounds the retarder and guides off neutrons back to the retarder to improve the intensity of the super-thermal neutron beam, the thermal neutron absorber is used for absorbing thermal neutrons to avoid excessive dose with shallow normal tissues during treatment, the radiation shield is used for shielding leaked neutrons and photons to reduce the dose of normal tissues in a non-irradiation region, the collimator is arranged at the rear part of the beam outlet to converge neutron beams, and a radiation shield is arranged between the patient and the beam outlet to shield the radiation of the beams coming out of the beam outlet to the normal tissues of the patient.

Furthermore, the beam transmission part is provided with a transmission pipe for accelerating or transmitting the charged particle beam, the transmission pipe extends into the beam shaping body along the direction of the charged particle beam and sequentially passes through the reflector and the speed reducing body, the target material is arranged in the speed reducing body and is positioned at the end part of the transmission pipe, a cooling pipe is arranged between the transmission pipe and the reflector and the speed reducing body, the cooling pipe is used for being connected with an external cooling source and cooling the target material, and the accommodating hole accommodates the cooling pipe.

The utility model discloses a neutron capture treatment system can avoid or reduce the leakage of neutron and other radiant rays that cause in the place that the shield wall is passed by subassembly or component, and the shield body is for mobilizable and have the position that the accommodation hole was opened, can be convenient for remove and provide operating space and not disturb the unmovable subassembly of beam transmission portion.

Drawings

Fig. 1 is a schematic structural diagram of a neutron capture therapy system according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a target structure of a neutron capture therapy system according to an embodiment of the present invention;

fig. 3 is a schematic layout view of a neutron capture therapy system in an embodiment of the present invention in an XY plane;

FIG. 4 is a schematic view of FIG. 3 taken at section A-A;

fig. 5 is a schematic view of an installation of a beam shaper support module of a neutron capture therapy system in an embodiment of the invention;

fig. 6 is a schematic structural diagram of a shielding body disposed at a position where a neutron beam generating part of the neutron capture treatment system passes through a shielding wall in an embodiment of the present invention;

fig. 7 is a schematic view of the shield of fig. 6 in another state.

Detailed Description

Embodiments of the present invention will be described in further detail with reference to the accompanying drawings so that those skilled in the art can implement the embodiments with reference to the description. An XYZ coordinate system (see fig. 3 and 4) is set in which the direction of the charged particle beam P emitted from the accelerator described later is an X axis, the direction orthogonal to the direction of the charged particle beam P emitted from the accelerator is a Y axis, and the direction perpendicular to the ground is a Z axis, and X, Y, Z is used to explain the positional relationship of the respective components.

Referring to fig. 1, the neutron capture treatment system in the present embodiment is preferably a boron neutron capture treatment system 100, and the boron neutron capture treatment system 100 is a device for cancer treatment using boron neutron capture therapy. The boron neutron capture therapy is used for treating cancer by irradiating a neutron beam N to a patient 200 injected with boron (B-10), wherein the patient 200 selectively accumulates the boron-containing drug in tumor cells M after administering or injecting the boron-containing drug, and then utilizes the characteristic of the boron-containing drug having a high capture cross section for thermal neutrons by using the boron-containing drug (B-10)¹⁰B(n,α)⁷Li neutron capture and nuclear fission reaction generation⁴He and⁷li two heavily charged particles. The average Energy of the two charged particles is about 2.33MeV, and the two charged particles have high Linear Energy Transfer (LET) and short-range characteristics, the Linear Energy Transfer and the range of the alpha particle are 150 keV/mu m and 8 mu m respectively, and⁷the Li-heavily-charged particles are 175 keV/mum and 5μm, and the total range of the two particles is about equal to the size of a cell, so that the radiation damage to organisms can be limited at the cell level, and the aim of locally killing tumor cells can be achieved on the premise of not causing too much damage to normal tissues.

The boron neutron capture treatment system 100 includes an accelerator 10, a beam transport section 20, a neutron beam generation section 30, and a treatment table 40. The accelerator 10 accelerates charged particles (such as protons, deuterons, etc.) to generate a charged particle beam P such as a proton beam; a beam transport unit 20 that transports the charged particle beam P generated by the accelerator 10 to the neutron beam generation unit 30; the neutron beam generating unit 30 generates a therapeutic neutron beam N and irradiates the patient 200 on the treatment table 40.

The neutron beam generating unit 30 includes a target T, a beam shaper 31, and a collimator 32, and irradiates the target T with the charged particle beam P generated by the accelerator 10 via the beam transport unit 20 to generate neutrons, which are then passed through the beam shaper 31 and the collimator 32 in order to form a neutron beam N for treatment and irradiate the patient 200 on the treatment table 40. The target T is preferably a metal target. The appropriate nuclear reactions are selected based on the desired neutron yield and energy, the available energy and current for accelerating charged particles, the physical properties of the metal target, and the like, and the nuclear reactions in question include⁷Li(p,n)⁷Be and⁹Be(p,n)⁹b, both reactions are endothermic. The energy threshold of the two nuclear reactions is 1.881MeV and 2.055MeV respectively, because the ideal neutron source for boron neutron capture treatment is epithermal neutrons with keV energy level, theoretically if a metallic lithium target is bombarded by protons with energy only slightly higher than the threshold, neutrons with relatively low energy can Be generated, and can Be used clinically without too much slowing treatment, however, the proton interaction cross section of the two targets of lithium metal (Li) and beryllium metal (Be) and the threshold energy is not high, and in order to generate enough neutron flux, protons with higher energy are usually selected to initiate the nuclear reaction. An ideal target should have the characteristics of high neutron yield, neutron energy distribution generated close to the hyperthermic neutron energy region (described in detail below), not too much intense penetrating radiation generation, safety, cheapness, easy operation, and high temperature resistance, but practically no nuclear reaction meeting all the requirements can be found. As is well known to those skilled in the art, the target T may Be made of a metal material other than Li and Be, for example, Ta or W, an alloy thereof, or the like. The accelerator 10 may be a linear accelerator, a cyclotron, a synchrotron, a synchrocyclotron.

The beam shaper 31 is capable of adjusting a charged particle beamThe collimator 32 is used for converging the neutron beam N, so that the neutron beam N has higher targeting property in the treatment process. The beam shaper 31 further includes a reflector 311, a retarder 312, a thermal neutron absorber 313, a radiation shield 314 and a beam outlet 315, wherein neutrons generated by the action of the charged particle beam P and the target T have a wide energy spectrum, and besides epithermal neutrons meet the treatment requirement, the content of neutrons and photons of other types needs to be reduced as much as possible to avoid injury to operators or patients, so that the neutrons coming out of the target T need to pass through the retarder 312 to adjust the fast neutron energy (greater than 40keV) in the epithermal neutron energy region (0.5eV-40keV) and reduce the thermal neutrons (less than 0.5eV) as much as possible, the retarder 312 is made of a material with a large fast neutron action section and a small epithermal neutron action section, in this embodiment, the retarder 312 is made of a material with a large fast neutron action section and a small epithermal neutron action section, and the₂O、AlF₃、Fluental^TM、CaF₂、Li₂CO₃、 MgF₂And Al₂O₃At least one of (a); the reflector 311 surrounds the retarder 312, reflects neutrons diffused to the periphery through the retarder 312 back to the neutron beam N to improve the utilization rate of the neutrons, and is made of a material with strong neutron reflection capability, in this embodiment, the reflector 311 is made of at least one of Pb or Ni; the thermal neutron absorber 313 is arranged at the rear part of the retarder 312 and is made of a material with a large thermal neutron acting section, in the embodiment, the thermal neutron absorber 313 is made of Li-6, the thermal neutron absorber 313 is used for absorbing thermal neutrons penetrating through the retarder 312 so as to reduce the content of the thermal neutrons in the neutron beam N, and excessive dose caused by the thermal neutrons and shallow normal tissues during treatment is avoided, so that the thermal neutron absorber can be integrated with the retarder, and the material of the retarder contains Li-6; the radiation shield 314 is used for shielding neutrons and photons leaking from a portion outside the beam outlet 315, and the material of the radiation shield 314 includes at least one of a photon shielding material and a neutron shielding material, and in this embodiment, the material of the radiation shield 314 includes lead (Pb) which is the photon shielding material and Polyethylene (PE) which is the neutron shielding material. It will be appreciated that the beam shaper 31 may have other configurations as long as the epithermal neutrons required for the treatment are obtainedIn the beam shaping body 31, radiation detection components (not shown) may be disposed to detect various kinds of radiation in the neutron generation process. The collimator 32 is disposed behind the beam outlet 315, and the hyperthermo neutron beam from the collimator 32 is irradiated to the patient 200, and is slowed down to thermal neutrons to the tumor cells M after passing through the shallow normal tissue, it being understood that the collimator 32 may be eliminated or replaced by other structures, and the neutron beam from the beam outlet 315 is irradiated directly to the patient 200. In this embodiment, a radiation shield 50 is disposed between the patient 200 and the beam outlet 315 to shield the beam exiting the beam outlet 315 from radiation of normal tissue of the patient, although it is understood that the radiation shield 50 may or may not be disposed.

The target T is disposed between the beam transmitting portion 20 and the beam shaping body 31, the beam transmitting portion 20 has a transmission tube C for accelerating or transmitting the charged particle beam P, in this embodiment, the transmission tube C extends into the beam shaping body 31 along the direction of the charged particle beam P and sequentially passes through the reflector 311 and the retarder 312, and the target T is disposed in the retarder 312 and at the end of the transmission tube C to obtain better neutron beam quality. It will be appreciated that the target may be arranged otherwise and may be movable relative to the accelerator or beam shaper to facilitate target exchange or to enable the charged particle beam to interact homogeneously with the target. Referring to fig. 2, the target T includes a heat dissipation layer 301, a base layer 302 and an active layer 303, the active layer 303 reacts with the charged particle beam P to generate a neutron beam, and the base layer 302 supports the active layer 303. In this embodiment, the material of the active layer 303 is Li or an alloy thereof, the charged particle beam P is a proton beam, the target T further includes an anti-oxidation layer 304 located on one side of the active layer 303 for preventing oxidation of the active layer, and the charged particle beam P sequentially passes through the anti-oxidation layer 304, the active layer 303, and the base layer 302 along the incident direction. The material of the oxidation resistant layer 304 is considered to be less susceptible to corrosion by the active layer and is capable of reducing loss of the incident proton beam and heat generation caused by the proton beam, such as at least one of Al, Ti, and alloys thereof, or stainless steel. The heat dissipation layer 301 is made of a material with good thermal conductivity (e.g. including at least one of Cu, Fe, and Al) or is at least partially made of the same material as the base layer or is integrated with the base layer. The heat dissipation layer can have various structures, such as a flat plate shape, and will not be described in detail in this embodiment. The heat dissipation layer 301 is provided with a cooling inlet IN (not shown), a cooling outlet OUT (not shown), and a cooling channel 3011 communicating the cooling inlet IN and the cooling outlet OUT, wherein a cooling medium enters from the cooling inlet IN and exits from the cooling outlet OUT through the cooling channel 3011. IN this embodiment, the first and

second cooling tubes

3012 and 3013 are disposed between the transport tube C and the reflector 311 and the retarder 312, one end of the first and

second cooling tubes

3012 and 3013 is connected to the cooling inlet IN and the cooling outlet OUT of the target T, respectively, and the other end is connected to an external cooling source. It will be appreciated that the first and second cooling tubes may be otherwise disposed within the beam shaper and may be eliminated when the target material is disposed outside of the beam shaper. Referring to fig. 3 and 4, the boron neutron capture therapy system 100 is disposed entirely in the space between the two stories L1 and L2, the boron neutron capture therapy system 100 further includes irradiation rooms 101(101A, 101B, and 101C) and a charged particle beam generation room 102, the patient 200 on the treatment table 40 is treated by irradiation with the neutron beam N in the irradiation rooms 101(101A, 101B, and 101C), and the charged particle beam generation room 102 accommodates the accelerator 10 and at least part of the beam transport unit 20. The neutron beam generating units 30 may have one or more than one to generate one or more than one therapeutic neutron beams N, and the beam delivery unit 20 may selectively deliver the charged particle beam P to one or more than one of the neutron beam generating units 30 or to a plurality of the neutron beam generating units 30 at the same time, wherein each of the neutron beam generating units 30 corresponds to one irradiation chamber 101. In this embodiment, there are 3 neutron beam generating sections and 3 irradiation chambers, namely, the neutron

beam generating sections

30A, 30B, and 30C and the

irradiation chambers

101A, 101B, and 101C, respectively. The beam transmitting section 20 includes: a first transmission unit 21 connected to the accelerator 10; first and second beam direction switching devices 22 and 23 for switching the traveling direction of the charged particle beam P; a second transmission unit 24 connected to the first and second beam direction switching devices 22 and 23; the third, fourth, and

fifth transport units

25A, 25B, and 25C transport the charged particle beam P from the first beam direction switching unit 22 or the second beam direction switching unit 23 to the neutron

beam generating units

30A, 30B, and 30C, respectively, and irradiate the generated neutron beam N to the patient in the

irradiation rooms

101A, 101B, and 101C, respectively. The third transfer unit 25A is connected to the first beam direction switching unit 22 and the neutron beam generating unit 30A, the fourth transfer unit 25B is connected to the second beam direction switching unit 23 and the neutron beam generating unit 30B, and the fifth transfer unit 25C is connected to the second beam direction switching unit 23 and the neutron beam generating unit 30C. That is, the first transfer section 21 is branched into the second transfer section 24 and the third transfer section 25A in the first beam direction switching device 22, and the second transfer section 24 is branched into the fourth transfer section 25B and the fifth transfer section 25C in the second beam direction switching device 23. The first and

second transport sections

21 and 24 transport in the X-axis direction, the third transport section 25A transports in the Z-axis direction, the fourth and

fifth transport sections

25B and 25C transport directions are in the XY plane and in the Y shape with the transport directions of the first and

second transport sections

21 and 24, the neutron

beam generating sections

30A, 30B and 30C and the

irradiation chambers

101A, 101B and 101C are respectively disposed along the transport directions of the third, fourth and

fifth transport sections

25A, 25B and 25C, and the generated neutron beam N direction is respectively the same as the transport directions of the third, fourth and

fifth transport sections

25A, 25B and 25C, so that the neutron

beam generating sections

30B and 30C generate neutron beams in the same plane, and the neutron beam generating section 30A generates a neutron beam in the direction perpendicular to the plane. By adopting the arrangement mode, the space can be effectively utilized, a plurality of patients can be treated at the same time, the transmission line of the beam is not excessively prolonged, and the loss is small. It is to be understood that the direction of the neutron beam N generated by the neutron beam generating section 30A (30B, 30C) and the transmission direction of the third (fourth, fifth) transmission section 25A (25B, 25C) may be different; the first and second transmission units 21 and 24 may have different transmission directions, and the second transmission unit 24 may be eliminated, and may have only one beam direction switching unit for branching the beam into 2 or more transmission portions; the transmission direction of the fourth and fifth transmission parts 25B and 25C is formed in a "Y" shape with the transmission direction of the first transmission part 21, and may be a modification of the "Y", for example, the transmission direction of the fourth transmission part 25B or the fifth transmission part 25C is the same as the transmission direction of the first transmission part 21, and the transmission direction of the fourth and fifth transmission parts 25B and 25C and the transmission direction of the first transmission part 21 may have other shapes, such as a "T" shape or an arrow shape, as long as the transmission direction of the fourth and fifth transmission parts 25B and 25C forms an included angle larger than 0 degree in the XY plane; the transfer directions of the fourth and fifth transfer units 25B and 25C are not limited to the XY plane, and the transfer direction of the third transfer unit 25A may not be along the Z axis, as long as two of the transfer direction of the fourth transfer unit 25B, the transfer direction of the fifth transfer unit 25C, and the transfer direction of the first transfer unit 21 are in the same plane (first plane), the transfer direction of the first transfer unit 21 and the transfer direction of the third transfer unit 25A are in the same plane (second plane), and the first plane and the second plane are different; the third transfer unit 25A, the neutron beam generating unit 30A, and the irradiation chamber 101A may be eliminated, and only beam transfer in the XY plane may be performed.

The first and second beam direction switching devices 22 and 23 include a deflection electromagnet for deflecting the charged particle beam P and a switching electromagnet for controlling the traveling direction of the charged particle beam P, and the boron neutron capture therapy system 100 may further include a beam dump (not shown) for checking the output of the charged particle beam P before therapy or the like, and the first or second beam direction switching devices 22 and 23 may guide the charged particle beam P out of the normal trajectory to the beam dump.

The first transmission part 21, the second transmission part 24, the third transmission part 25A, the fourth transmission part 25B and the fifth transmission part 25C are all constructed by a transmission pipe C, and can be formed by connecting a plurality of sub-transmission parts respectively, the transmission directions of the plurality of sub-transmission parts can be the same or different, for example, the deflection of the transmission direction of the beam is carried out by a deflection electromagnet, the transmission direction of the first transmission part, the second transmission part, the third transmission part, the fourth transmission part and the

fifth transmission part

21, 24, 25A, 25B and 25C can be the transmission direction of any one of the sub-transmission parts, and the formed first plane and the second plane are planes formed between the sub-transmission parts directly connected with the beam direction switcher; the beam adjuster may include a beam adjuster (not shown) for the charged particle beam P, and the beam adjuster may include a horizontal deflector and a horizontal vertical deflector for adjusting the axis of the charged particle beam P, a quadrupole electromagnet for suppressing divergence of the charged particle beam P, a four-way cutter for shaping the charged particle beam P, and the like. The third, fourth, and

fifth transport units

25A, 25B, and 25C may include a current monitor (not shown) and a charged particle beam scanning unit (not shown) as necessary. The current monitor measures the current value (i.e., charge and irradiation dose rate) of the charged particle beam P irradiated to the target T in real time. The charged particle beam scanning unit scans the charged particle beam P and controls irradiation of the charged particle beam P with respect to the target T, for example, controls an irradiation position of the charged particle beam P with respect to the target T.

The charged particle beam generation chamber 102 may include an accelerator chamber 1021 and a beam transport chamber 1022, the accelerator chamber 1021 being two-layered, the accelerator 10 extending from L2 to L1. The beam transport chamber 1022 is located at L2, and the first transport portion 21 extends from the accelerator chamber 1021 to the beam transport chamber 1022.

Irradiation chambers

101B and 101C are located at L2, and irradiation chamber 101A is located at L1. In the embodiment, the L1 is below the L2, that is, the floor of the L2 is the ceiling of the L1, but it should be understood that the opposite configuration is also possible. The material of the floor (ceiling) S may be concrete having a thickness of 0.5m or more or boron-containing barite concrete. The

irradiation chambers

101A, 101B, 101C and the beam transmission chamber 1022 include a shield space surrounded by a shield wall W1, the shield wall W1 may be a boron-containing barite concrete wall having a thickness of 1m or more and a density of 3g/c.c., and includes a first partition shield wall W2 for partitioning the beam transmission chamber 1022 from the

irradiation chambers

101B, 101C, a second partition shield wall W3 for partitioning the accelerator chamber 1021 and the beam transmission chamber 1022 from the L1, and a third partition shield wall W4 for partitioning the accelerator chamber 1021 and the irradiation chamber 101A from the L2. The accelerator chamber 1021 is surrounded by a concrete wall W having a thickness of 1m or more, a second partition wall W3, and a third partition wall W4. At least a part of the neutron

beam generating units

30B and 30C is embedded in the first partition wall W2, and the fourth and fifth transmitting

units

25B and 25C extend from the beam transmitting chamber 1022 to the neutron

beam generating units

30B and 30C; the neutron beam generating unit 30A is located in the irradiation chamber 101A, and the third transfer unit 25A extends from the beam transfer chamber 1022 to the irradiation chamber 101A through the floor S. The

irradiation rooms

101A, 101B, and 101C have barrier doors D1, D2, and D3 for the treatment table 40 and the doctor to enter and exit, respectively, the accelerator room 1021 has barrier doors D4 and D5 for maintenance of the accelerator 10 by entering and exiting the accelerator room 1021 at L1 and L2, respectively, the beam transport room 1022 has a barrier door D6 for maintenance of the beam transport unit 20 by entering and exiting the beam transport room 1022 from the accelerator room 1021, and the barrier door D6 is provided on a second partition barrier wall W3. The

irradiation chambers

101A, 101B, 101C further have an inner shield wall W5 therein to form a labyrinth passage from the shield doors D1, D2, D3 to the beam outlet, so as to prevent direct irradiation of radiation when the shield doors D1, D2, D3 are opened accidentally, the inner shield wall W5 may be disposed at different positions according to different layouts of the irradiation chambers, and the shield door D7 inside the irradiation chamber may be disposed between the inner shield wall W5 and the shield wall W1 or the third partition shield wall W4, thereby forming secondary protection when the beamlet irradiation treatment is performed. The inner shielding wall W5 can be a boron-containing barite concrete wall with the thickness of more than 0.5m and the density of 3 g/c.c.; the shielding doors D1, D2, D3, D4, D5, D6 and D7 can be composed of two independent layers of a main shielding door D and a secondary shielding door D ' or only the main shielding door D or the secondary shielding door D ', and can be determined according to actual conditions, the main shielding door D can be made of the same material and has the thickness of more than 0.5m and the density of 6g/c.c. and the secondary shielding door D ' can be made of the same material and has the thickness of more than 0.2m and the density of 6 g/c.c.c. and has the boron-containing PE or barite concrete or lead. In this embodiment, the shielding doors D1, D4, D5 and D6 are composed of a main shielding door D and a sub-shielding door D ', the shielding doors D1, D2 and D3 only include the main shielding door D, and the shielding door D7 only includes the sub-shielding door D'. The shielding walls and the shielding doors form a shielding space, and prevent radiation from entering the inside of the

irradiation chambers

101A, 101B, and 101C and the beam transmission chamber 1022 from the outside and from being emitted from the inside to the outside. In the present embodiment, the second separating and shielding wall W3 separating the accelerator chamber 1021 and the beam transport chamber 1022 is disposed between the accelerator 10 and the first beam direction switching unit 22, that is, the first transport unit 21 passes through the second separating and shielding wall W3, it is understood that the second separating and shielding wall W3 and the shielding door D6 may be eliminated, or disposed at other positions, such as between the first and second beam direction switching units 22 and 23 or between the second beam direction switching unit 23 and the neutron

beam generating units

30B and 30C; or additional partition shield walls and shield doors are provided between the second partition shield wall W3 and the first partition shield wall W2. That is, a shielding wall is provided between the neutron beam generating unit and the accelerator, so that an operator is prevented from being irradiated with neutrons and other radiation rays leaking from the neutron beam generating unit during maintenance and repair of the accelerator, and the reaction of the accelerator activated by neutrons is reduced.

Referring to fig. 5, the beam shaper 31 is supported by the support module 60 disposed in the partition wall 103 (the first partition shielding wall W2), a receiving groove 1031 for at least partially receiving the support module 60 is disposed on a side of the partition wall 103 close to the irradiation chamber 101, and a slot 1032 for passing a transport tube of an accelerator or the like is disposed on a side close to the charged particle beam generation chamber 102, so that the receiving groove 1031 and the slot 1032 penetrate the partition wall in the traveling direction of the neutron beam N, in this embodiment, a wall surface of the partition wall 103 is a plane, and the traveling direction of the neutron beam N is perpendicular to the wall surface of the partition wall 103. The support structure is modularized, so that the beam shaping body can be locally adjusted, the precision requirement is met, the beam quality is improved, and the assembly tolerance of the target is met. The cross-sectional profile of the support module 60 is located between the cross-sectional profiles of the receiving

grooves

1031 and 1032 in a plane perpendicular to the direction of propagation of the neutron beam N, thereby avoiding through-slits in the direction of propagation of the beam, further reducing radiation, and facilitating adjustment of the support module 60. In this embodiment, the support module 60 is a rectangular parallelepiped, the cross sections of the receiving grooves 1031 and the grooves 1032 perpendicular to the transmission direction of the neutron beam N are both "Jiong", and the side walls of the receiving grooves 1031 and the grooves 1032 are parallel to the transmission direction of the neutron beam N. The shielding plate 1033 is further disposed on a side of the partition wall 103 close to the irradiation chamber 102, and the shielding plate 1033 can enhance the shielding effect of the partition wall and suppress the secondary radiation generated by the partition wall, thereby avoiding the radiation to the normal tissue of the patient. The shielding plate 1033 may be matched with a cross-sectional profile of the support module 60 in a plane perpendicular to a transmission direction of the neutron beam N, thereby shielding neutrons leaking from between the support module and the partition wall. The shielding plate is a PE plate, and it is understood that the shielding plate may be provided on the side of the partition wall 103 close to the charged particle beam generating chamber 102 and on the side of the support module 60 close to the irradiation chamber 101, and the shielding plate may be made of other neutron or photon shielding material such as lead, or may not be provided.

The outgoing directions of neutrons generated by the action of the charged particle beams P and the target T are almost uniformly distributed in space, and meanwhile, a large amount of recoil neutrons are generated in the process of shaping the neutrons by the beam shaper 31, and the recoil neutrons are important parts to be considered in radiation shielding design. In the present embodiment, the neutron

beam generating sections

30B and 30C pass through the first partition shielding wall W2, the first transmission section 21 passes through the second partition shielding wall W3, and the third transmission section 25A passes through the floor S, and the first shielding body 70, the second shielding body 80, and the third shielding body 90 may be provided at positions through which the neutron

beam generating sections

30B and 30C, the first transmission section 21, and the third transmission section 25A pass on the side of the first partition shielding wall W2, the second partition shielding wall W3, and the floor S facing the beam transmission direction upstream, respectively. The first shield 70 covers the end portions of the neutron

beam generating units

30B and 30C facing the accelerator, and prevents neutrons that overflow or are reflected from the beam shaping bodies of the neutron

beam generating units

30B and 30C from entering the accelerator chamber 1021 and the beam transport chamber 1022, and the fourth and

fifth transport units

25B and 25C pass through the first shield 70 and reach the target T of the neutron

beam generating units

30B and 30C. The second shield 80 prevents neutrons that overflow or reflect from the beam transmitting section 20 from entering the accelerator chamber 1021, and the first transmitting section 21 passes through the second shield 80 and the second partition shielding wall W3 to reach the first beam direction switcher 22. The third shield 90 prevents neutrons overflowing or reflected from the irradiation chamber 101A from entering the beam transmission chamber 1022, and the third transmission section 25A passes through the third shield 90 and the floor S to reach the neutron beam generating section 30A. The material of the first, second and

third shields

70, 80, 90 may be PE or barite concrete or lead containing boron, and may also include other neutron shielding materials.

The first, second and

third shields

70, 80, 90 are described in detail below with reference to the first shield 70 as an example. In this embodiment, the first shield 70 is movable having a first position and a second position. In the first position, the accommodating hole 71 through which the fourth and fifth transmission parts 25B and 25C pass is formed, and covers the end parts of the neutron beam generation parts 30B and 30C facing the accelerator 10, so as to shield the recoil neutrons, limit the high neutron dose region, protect the accelerator assembly, reduce the radiation damage of the assembly, reduce the element activation of the accelerator assembly, and simultaneously protect one irradiation chamber when the other irradiation chamber is operated, and ensure that the radiation dose of the non-operating irradiation chamber is at a safe level; in the second position, the receiving hole 71 is opened to expose the end of the neutron beam generating parts 30B and 30C facing the accelerator 10, an operating space is formed without removing the transport pipe C passing through the receiving hole 71, the neutron beam generating parts 30B and 30C, such as the target T, the beam shaper 31, the radiation detecting element or the first and second cooling pipes 3012 and 3013 arranged in the beam shaper 31, can be replaced when the accelerator 10 is closed, a space is provided for removing a part of the transport pipe during replacement, or the beam transport part 20 passing through the first separating shielding wall W2 and the first shielding body 70 can be installed, debugged and maintained. The receiving hole may receive the transport tubes C, magnets, etc. of the fourth and

fifth transport sections

25B, 25C, and may also receive the first and

second cooling tubes

3012, 3013 or other functional components, which may facilitate movement of the immovable components that provide the operating space without interfering with the beam transport section. The first shield 70 and the first partition shield wall W2 may be in close contact to enhance the shielding effect, or may have a gap, and the shielding effect may be achieved by adjusting the size of the first shield 70.

As shown in fig. 6 and 7, the first shielding body 70 includes a first shielding part 72 and a second shielding part 73, the first shielding part 72 and the second shielding part 73 move to a first position along the first and second directions L1, L2 close to the neutron

beam generating parts

30B, 30C, respectively, the first shielding part 72 and the second shielding part 73 have a first and

second groove

721, 731, respectively, the first and

second grooves

721, 731 form a receiving hole 71 through which the fourth and fifth transmitting

parts

25B, 25C pass together in the first position, and cover the end parts of the neutron

beam generating parts

30B, 30C facing the accelerator 10; the first and

second shielding parts

72 and 73 move in the third and fourth directions L3 and L4, respectively, away from the neutron

beam generating parts

30B and 30C to the second position where the accommodation hole 71 is opened to expose the end of the neutron

beam generating parts

30B and 30C toward the accelerator 10, thereby forming an operation space without removing the transmission tube C passing through the accommodation hole 71. It is understood that the first shield 70 may also include the third shield portion or be composed of three or more shield portions.

In the present embodiment, the first shielding part 72 and the second shielding part 73 slide along the guide rail 74, the guide rail 74 and the roller 75 fixed to the first shielding part 72 and the second shielding part 73 constitute a sliding assembly of the first shielding body 70, the first shielding part 72 and the second shielding part 73 are configured as double-opening sliding doors, the guide rail 74 is fixed to the side of the first partition shielding wall W2 facing the charged particle beam generating chamber 102, and the extending direction is parallel to the ground (XY plane), it can be understood that the first shielding part 72 and the second shielding part 73 and the sliding assembly may have other arrangements, and may be moved by other means, such as rotation.

The first and second beam direction switching devices 22 and 23 are each surrounded by a shield 26 to prevent the leakage of neutrons and other radiation from the beam direction switching devices, and the material of the shield 26 may be PE or barite concrete containing boron or lead. It will be appreciated that the first and second beam direction switches 22, 23 may also be entirely enclosed by a shield 26; other portions of the beam transport, such as vacuum tubes, may also be surrounded by a shield to prevent neutrons and other radiation from leaking out of the beam transport.

The boron neutron capture treatment system 100 can further comprise a preparation room, a control room and other spaces for auxiliary treatment, each irradiation room can be provided with a preparation room for fixing a patient to a treatment table, injecting boron drugs, simulating a treatment plan and the like before irradiation treatment, a connecting channel is arranged between the preparation room and the irradiation room, the patient is pushed into the irradiation room directly after the preparation is finished or automatically enters the irradiation room under the control of a control mechanism through a track, the preparation room and the connecting channel are also closed by shielding walls, and the preparation room is further provided with a shielding door. The control room is used for controlling the accelerator, the beam transmission part, the treatment table and the like, the whole irradiation process is controlled and managed, and a manager can simultaneously monitor a plurality of irradiation rooms in the control room.

It is understood that the shield wall (including the concrete wall W), the shield door, the shield body, and the shield can in this embodiment may have other thicknesses or densities or be replaced with other materials.

Although illustrative embodiments of the invention have been described above to facilitate the understanding of the invention by those skilled in the art, it should be understood that the invention is not limited to the scope of the embodiments, and that various changes may be apparent to those skilled in the art without departing from the spirit and scope of the invention as defined and defined in the appended claims.

Claims

1. A neutron capture treatment system comprises an accelerator, a beam transmission part and a neutron beam generation part, the accelerator accelerates charged particles to generate a charged particle beam, the beam transport unit transports the charged particle beam generated by the accelerator to the neutron beam generation unit, the neutron beam generation unit generates a therapeutic neutron beam, characterized in that the neutron capture treatment system further comprises a shielding wall accommodating the accelerator, the beam transmission part and the neutron beam generation part, a shield body is provided at a portion of the shield wall that is passed through by the beam delivery section or the neutron beam generating section on a side toward an upstream side in the beam delivery direction, the shield body being movable and having a first position and a second position, in the first position, an accommodation hole through which the beam transmitting portion passes is formed, and in the second position, the accommodation hole is opened.

2. The neutron capture treatment system of claim 1, further comprising a charged particle beam generation chamber and an irradiation chamber, wherein the charged particle beam generation chamber accommodates the accelerator and at least a part of the beam transport unit, wherein a patient is treated by irradiation of a neutron beam in the irradiation chamber, wherein the shielding wall includes a partition wall of the irradiation chamber and the charged particle beam generation chamber, wherein at least a part of the neutron beam generation unit is embedded in the partition wall, wherein an end of the neutron beam generation unit facing the accelerator is covered in the first position, and wherein an end of the neutron beam generation unit facing the accelerator is at least partially exposed in the second position.

3. The neutron capture treatment system of claim 2, wherein the beam transmission part includes a first transmission part connected to the accelerator, a beam direction switch that switches a traveling direction of the charged particle beam, and a second transmission part that transmits the charged particle beam to the neutron beam generation part, the second transmission part passing through the shield to reach the neutron beam generation part, and the accommodation hole accommodates the second transmission part.

4. The neutron capture treatment system of claim 2, wherein a side of the partition wall adjacent to the irradiation chamber is provided with a receiving groove for at least partially receiving the neutron beam generating part and the support module for supporting the neutron beam generating part, a side adjacent to the charged particle beam generating chamber is provided with a slot for the beam transport part to pass through, the receiving groove and the slot penetrate the partition wall in the neutron beam transport direction, and a cross-sectional profile of the neutron beam generating part and the support module thereof is located between cross-sectional profiles of the receiving groove and the slot on a plane perpendicular to the neutron beam transport direction.

5. The neutron capture therapy system of claim 1, wherein the shield includes a first shield portion and a second shield portion, the first shield portion and the second shield portion moving to the first position in first and second directions, respectively, proximate to the neutron beam generating portion, the first shield portion and the second shield portion having first and second recesses, respectively, that collectively form the receiving aperture in the first position.

6. The neutron capture therapy system of claim 5, wherein the first shield and the second shield slide along a rail fixed to a side of the shield wall facing upstream in a beam transmission direction and extending parallel to ground.

7. The neutron capture therapy system of claim 5, wherein the material of the first and second shields comprises neutron shielding material, and the material of the first and second shields is boron-containing PE or barite concrete or lead.

8. The neutron capture therapy system according to claim 1, further comprising a therapy table, wherein the neutron beam generating section includes a target material, a beam shaper, and a collimator, the target material is disposed between the beam transport section and the beam shaper, the charged particle beam generated by the accelerator is irradiated to the target material through the beam transport section and reacts with the target material to generate neutrons, and the generated neutrons sequentially pass through the beam shaper and the collimator to form a therapeutic neutron beam and are irradiated to a patient on the therapy table.

9. The neutron capture therapy system of claim 8, wherein the beam shaper comprises a reflector, a retarder, a thermal neutron absorber, a radiation shield, and a beam outlet, the retarder retards neutrons generated from the target material to a epithermal neutron energy region, the reflector surrounds the retarder and guides off neutrons back to the retarder to improve the intensity of epithermal neutron beams, the thermal neutron absorber is used for absorbing thermal neutrons to avoid causing excessive dose with shallow normal tissues during treatment, the radiation shield is used to shield the leak neutrons and photons from reducing the normal tissue dose in the non-illuminated region, the collimator is arranged behind the beam outlet to focus the neutron beam, and a radiation shielding device is arranged between the patient and the beam outlet to shield the beam from the beam outlet to the normal tissue of the patient.

10. The neutron capture therapy system of claim 9, wherein the beam transport section has a transport tube for accelerating or transporting the charged particle beam, the transport tube extending into the beam shaper in a direction of the charged particle beam and sequentially passing through the reflector and the retarder, the target material being disposed in the retarder at an end of the transport tube, a cooling tube being disposed between the transport tube and the reflector and the retarder for connecting to an external cooling source and cooling the target material, the receiving hole accommodating the cooling tube.