TWI809851B - neutron capture therapy system - Google Patents

Abstract

The invention provides a neutron capture therapy system, which can avoid or reduce the leakage of neutrons and other radiation caused by the shielding wall or floor where components or elements pass through, and the neutron shielding structure can reduce the installation mechanism or drive The body produces secondary radiation after being irradiated by neutrons. The neutron capture therapy system of the present invention includes an accelerator, a beam transmission part, a neutron beam generation part, and a shielding wall for accommodating the accelerator, a beam transmission part, and a neutron beam generation part. A shielding body is provided on one side where the beam transmission part or the neutron beam generation part passes. The neutron capture therapy system also includes a mounting mechanism or a driving mechanism for the shielding body. The wall faces the upstream side of the beam transmission direction, the driving mechanism is used to drive the movement of the shielding body, and the installation mechanism or the driving mechanism is provided with a neutron shielding structure.

Description

neutron capture therapy system

The invention relates to a radiation irradiation system, in particular to a neutron capture therapy system.

With the development of atomic science, radiation therapy such as cobalt 60, linear accelerator, and electron beam has become one of the main means of cancer treatment. However, traditional photon or electron therapy is limited by the physical conditions of the radiation itself. While killing tumor cells, it will also cause damage to a large number of normal tissues along the beam path; in addition, due to the different sensitivity of tumor cells to radiation, traditional radiation therapy Treatment outcomes for more radiation-resistant malignancies (eg, glioblastoma multiforme, melanoma) are often poor.

In order to reduce the radiation damage to normal tissues around the tumor, the concept of targeted therapy in chemotherapy (chemotherapy) has been applied to radiation therapy; and for tumor cells with high radiation resistance, it is also actively developing tumor cells with high relative biological effects (relative biological effects). Biological effectiveness (RBE) radiation sources, such as proton therapy, heavy particle therapy, neutron capture therapy, etc. Among them, neutron capture therapy is a combination of the above two concepts, such as boron neutron capture therapy, through the specific accumulation of boron-containing drugs in tumor cells, combined with precise neutron beam regulation, it provides better treatment than traditional radiation. Cancer treatment options.

Various radiations are produced during radiation therapy, such as low-energy to high-energy neutrons and photons generated during boron neutron capture therapy, which may cause varying degrees of damage to normal tissues of the human body. Therefore, in the field of radiation therapy, how to achieve effective treatment while reducing radiation pollution to the external environment, medical staff or normal tissues of patients is an extremely important issue. Radiation therapy equipment is usually set in a space surrounded by shielding materials. The shielding wall formed by the shielding material cannot achieve closed shielding where components or components pass through, which is likely to cause radiation leakage. Set up a shielding structure that strengthens the shielding effect; the auxiliary parts between the reinforced shielding structure and the shielding wall are usually steel structures. After the steel is irradiated by neutrons, radioactive isotopes with long half-lives, such as cobalt 60, form secondary radiation, which is harmful to the environment and Radiation safety has a negative impact.

Therefore, it is necessary to propose a new technical solution to solve the above problems.

In order to solve the above problems, the present invention provides a neutron capture therapy system, which includes an accelerator, a beam transmission part, and a neutron beam generation part. The accelerator accelerates charged particles to generate a charged particle beam, and the beam transmission The charged particle beam generated by the accelerator is transmitted to the neutron beam generation part, and the neutron beam generation part generates a neutron beam for treatment. The neutron capture therapy system also includes a The shielding wall of the space of the beam transmission part and the neutron beam generation part is provided with shielding at the position where the beam transmission part or the neutron beam generation part passes through on the side of the shielding wall facing the upstream side of the beam transmission direction body, the neutron capture therapy system further includes a mounting mechanism or a driving mechanism of the shielding body, the mounting mechanism is used to movably install the shielding body at a position upstream of the shielding wall toward the beam transmission direction On the side, the driving mechanism is used to drive the shielding body to move, and the driving mechanism can be manually driven or electrically driven. The shielding body can avoid or reduce the leakage of neutrons and other radiation caused by the shielding wall passing through the components or elements. The installation mechanism of the shielding body is provided with a first neutron shielding structure or the driving mechanism is provided with a second shielding structure. The neutron shielding structure reduces the secondary radiation generated by the installation mechanism or the drive mechanism after being irradiated by neutrons.

Preferably, the installation mechanism includes a first connecting piece carrying the shielding body, and the first neutron shielding structure shields an exposed part of the first connecting piece.

Further, the installation mechanism includes guide rails and rollers, the guide rails are fixed on the side of the shielding wall facing the upstream side of the beam transmission direction, the rollers are fixed on the shield body, and the shield body can pass through the rollers along the The rail slides.

Furthermore, the installation mechanism includes a frame, the shielding body is a plate fixed to the frame, a connecting plate is fixed on the top of the frame, and the roller is fixed to the connecting plate through a first connecting piece. Furthermore, the first connecting piece passes through the connecting plate, and the roller is installed on one end of the first connecting piece, and the first neutron shielding structure covers the part protruding from the connecting plate at the other end of the first connecting piece or covers the first connecting piece on the The part between the roller and the connecting plate or cover the first connecting piece overlaps with the connecting plate and the exposed part or the whole covers the first connecting piece and the connecting plate.

As a preference, the driving mechanism includes a fixed bracket and a second connecting piece carrying the driving mechanism, the fixing bracket is fixedly mounted to the shielding wall through the second connecting piece, and the second neutron shielding structure includes Cover the baffle of the second connecting piece. Further, the baffle is fixed on the fixed bracket, and shields the second connecting member on the side facing the upstream of the beam transmission direction, which may be L-shaped or "⊐"-shaped or circumferentially closed.

As a preferred embodiment, the driving mechanism includes a cylinder, the cylinder includes a cylinder body, and the second neutron shielding structure includes a collar covering the periphery of the cylinder body.

Further, the cylinder is fixed to the shielding wall, such as through a fixed bracket; the cylinder also includes a piston, one end of the piston extends into the cylinder, and the other end of the piston is connected to the shielding body, For example, it is fixedly connected to the shield body through the connecting rod.

Furthermore, the driving mechanism further includes a transmission member connected to the piston, the shielding body includes a first shielding part and a second shielding part, and the first shielding part and the second shielding part are connected between the cylinder and the second shielding part. Driven by the transmission member, it moves in the opposite direction.

Furthermore, the transmission member includes a sprocket and chains on both sides of the sprocket, the chain can move around the sprocket; the chains on both sides of the sprocket are connected to the first shielding part and the The second shielding part, such as the chains on both sides of the sprocket, are respectively fixedly connected to the first and second frames that fix the first shielding part and the second shielding part, and the piston of the cylinder is connected to the first frame or the second frame, so The first shielding part and the second shielding part move in opposite directions driven by the piston and the chain.

As a preference, the material of the first and second neutron shielding structures is boron-containing resin or boron-containing glass fiber composite material.

As a preference, the materials of the first shielding part and the second shielding part are neutron shielding materials, such as boron-containing PE; the materials of the first and second frames are neutron-irradiated products without Materials that are radioactive or products with low radioactivity after neutron irradiation or radioactive isotopes with short half-lives after neutron irradiation, such as aluminum alloys.

As a preference, the materials of the first and second connecting pieces and the cylinder body are steel.

The neutron capture therapy system of the present invention can avoid or reduce the leakage of neutrons and other radiation caused by components or components passing through the shielding wall. The installation mechanism or driving mechanism of the shielding body includes a neutron shielding structure, which avoids Secondary radiation is generated after the installation mechanism or drive mechanism is irradiated by neutrons.

Embodiments of the present invention will be described in further detail below in conjunction with the drawings, so that those skilled in the art can implement them with reference to the description. Set an XYZ coordinate system in which the direction of the charged particle beam P emitted from the accelerator described later is the X axis, the direction perpendicular to the direction of the charged particle beam P emitted by the accelerator is the Y axis, and the direction perpendicular to the ground is the Z axis. (Refer to FIG. 3 and FIG. 4 ), and X, Y, and Z are used in the description of the positional relationship of each component.

Referring to FIG. 1 , the neutron capture therapy system in this embodiment is preferably a boron neutron capture therapy system 100 , and the boron neutron capture therapy system 100 is a device for cancer treatment using boron neutron capture therapy. Boron neutron capture therapy performs cancer treatment by irradiating a neutron beam N to a patient 200 injected with boron (B-10), which is selectively aggregated after the patient 200 takes or injects a drug containing boron (B-10) In tumor cell M, boron-containing (B-10) drugs have a high capture cross-section for thermal neutrons, and ⁴ He and ⁷ Li are produced by ¹⁰ B(n,α) ⁷ Li neutron capture and nuclear fission reaction. a heavily charged particle. The average energy of the two charged particles is about 2.33MeV, with high linear energy transfer (Linear Energy Transfer, LET) and short range characteristics. The linear energy transfer and range of α particles are 150keV/μm and 8μm, respectively, while ^{the 7} Li heavy particles are 175keV/μm, 5μm, the total range of the two particles is about the size of a cell, so the radiation damage to the organism can be limited to the cell level, and it can achieve local killing without causing too much damage to normal tissues purpose of tumor cells.

The boron neutron capture therapy system 100 includes an accelerator 10 , a beam transmission part 20 , a neutron beam generation part 30 and a treatment table 40 . Accelerator 10 accelerates charged particles (such as protons, deuterons, etc.) to generate charged particle beams P such as proton beams; beam transmission part 20 transmits charged particle beams P generated by accelerator 10 to neutron beam generation part 30; The neutron beam generator 30 generates a therapeutic neutron beam N and irradiates the patient 200 on the treatment table 40 .

The neutron beam generation part 30 includes a target T, a beam shaper 31, and a collimator 32. The charged particle beam P generated by the accelerator 10 is irradiated to the target T through the beam transmission part 20 and interacts with the target T to generate neutrons. , the generated neutrons sequentially pass through the beam shaper 31 and the collimator 32 to form a therapeutic neutron beam N and irradiate the patient 200 on the treatment table 40 . The target T is preferably a metal target. Select the appropriate nuclear reaction based on the required neutron yield and energy, the available accelerated charged particle energy and current, and the physical and chemical properties of the metal target. The nuclear reactions that are often discussed are ⁷ Li(p,n) ⁷ Be and ⁹ Be(p,n) ⁹ B, both reactions are endothermic reactions. The energy thresholds of the two nuclear reactions are 1.881MeV and 2.055MeV respectively. Since the ideal neutron source for boron neutron capture therapy is epithermal neutrons at the keV energy level, in theory, if protons with energy only slightly higher than the threshold are used to bombard the metal Lithium targets can produce relatively low-energy neutrons, and can be used clinically without too much slowing treatment. However, lithium metal (Li) and beryllium metal (Be) two targets have different proton interaction cross-sections with threshold energy. High, in order to generate a sufficiently large neutron flux, usually a higher energy proton is selected to initiate a nuclear reaction. An ideal target should have the characteristics of high neutron yield, neutron energy distribution close to the epithermal neutron energy region (described in detail below), no strong penetrating radiation, safe, cheap, easy to operate, and high temperature resistance. It is practically impossible to find a nuclear reaction that meets all the requirements. As is well known to those skilled in the art, the target T may also be made of metal materials other than Li and Be, for example, Ta or W and alloys thereof. The accelerator 10 may be a linear accelerator, a cyclotron, a synchrotron, or a synchrocyclotron.

The beam shaper 31 can adjust the beam quality of the neutron beam N generated by the interaction between the charged particle beam P and the target T, and the collimator 32 is used to converge the neutron beam N so that the neutron beam N can Has high targeting. The beam shaping body 31 further includes a reflector 311, a slowing body 312, a thermal neutron absorber 313, a radiation shielding body 314, and a beam outlet 315. The neutrons generated by the interaction between the charged particle beam P and the target T have a wide energy spectrum , in addition to epithermal neutrons to meet the needs of treatment, it is necessary to reduce the content of other types of neutrons and photons as much as possible to avoid harm to operators or patients, so the neutrons from the target T need to pass through the retarder 312 The fast neutron energy (>40keV) is adjusted to the epithermal neutron energy region (0.5eV-40keV) and the thermal neutrons (<0.5eV) are reduced as much as possible. Made of materials with small functional cross-sections. In this embodiment, the retarder 312 is made of at least one of D ₂ O, AlF ₃ , Fluental ^TM , CaF ₂ , Li ₂ CO ₃ , MgF ₂ and Al ₂ O ₃ ; The reflector 311 surrounds the retarder 312, and reflects the neutrons diffused around the retarder 312 back to the neutron beam N to improve the utilization rate of neutrons. It is made of a material with strong neutron reflection ability. In this embodiment, the reflector 311 is made of at least one of Pb or Ni; there is a thermal neutron absorber 313 at the rear of the slowing body 312, which is made of a material with a large cross-section with thermal neutrons. The neutron absorber 313 is made of Li-6, and the thermal neutron absorber 313 is used to absorb the thermal neutrons passing through the slowing body 312 to reduce the content of thermal neutrons in the neutron beam N, avoiding excessive interference with shallow normal tissues during treatment. Dose, it can be understood that the thermal neutron absorber can also be integrated with the slowing body, and the material of the slowing body contains Li-6; the radiation shielding body 314 is used to shield neutrons and photons leaking from parts other than the beam exit 315 The material of the radiation shielding body 314 includes at least one of a photon shielding material and a neutron shielding material. In this embodiment, the material of the radiation shielding body 314 includes photon shielding material lead (Pb) and neutron shielding material polyethylene (PE). . It can be understood that the beam shaping body 31 can also have other structures, as long as the epithermal neutron beam required for treatment can be obtained, and a radiation detection component (not shown) can also be installed in the beam shaping body 31 to monitor the neutron generation process. Various radiation in the detection. The collimator 32 is arranged at the rear of the beam exit 315, and the epithermal neutron beam coming out of the collimator 32 is irradiated to the patient 200, and after passing through the shallow normal tissue, it is slowed into thermal neutrons and reaches the tumor cell M. It can be understood that the collimation The neutron beam 32 can also be canceled or replaced by other structures, and the neutron beam comes out from the beam outlet 315 to irradiate the patient 200 directly. In this embodiment, a radiation shielding device 50 is also provided between the patient 200 and the beam outlet 315 to shield the radiation from the beam coming out of the beam outlet 315 to the patient's normal tissues. It can be understood that the radiation shielding device 50 may not be provided .

The target T is arranged between the beam transmission part 20 and the beam shaper 31. The beam transmission part 20 has a transmission tube C for accelerating or transmitting the charged particle beam P. In this embodiment, the transmission tube C is along the charged particle beam P. The beam P extends into the beam shaping body 31, and passes through the reflector 311 and the slowing body 312 in sequence. The target T is arranged in the slowing body 312 and is located at the end of the transmission tube C, so as to obtain better neutron radiation. beam quality. It can be understood that the target can be arranged in other ways, and can also be movable relative to the accelerator or the beam shaper, so as to facilitate changing the target or make the charged particle beam interact with the target uniformly. 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 its alloy, the charged particle beam P is a proton beam, and the target T also includes an anti-oxidation layer 304 located on the active layer 303 side to prevent oxidation of the active layer. 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 anti-oxidation layer 304 is not easy to be corroded by the active layer and can reduce the loss of the incident proton beam and the heating caused by the proton beam, such as including at least one of Al, Ti and their alloys, or stainless steel. The heat dissipation layer 301 is made of a material with good thermal conductivity (for example, at least one of Cu, Fe, and Al), or at least partly uses the same material as the base layer or is integrated. The heat dissipation layer can have various structures, such as a flat plate shape, which will not be described in detail in this embodiment. The heat dissipation layer 301 is provided with a cooling inlet IN (not shown in the figure), a cooling outlet OUT (not shown in the figure), and a cooling channel 3011 connecting the cooling inlet IN and the cooling outlet OUT. Exit OUT out. In this embodiment, the first and second cooling pipes 3012 and 3013 are arranged between the transmission pipe C and the reflector 311 and retarder 312, and one end of the first and second cooling pipes 3012 and 3013 are respectively connected to the cooling inlet of the target T IN is connected to the cooling outlet OUT, and the other end is connected to an external cooling source. It can be understood that the first and second cooling pipes can also be arranged in the beam shaping body in other ways, and can be canceled when the target is placed outside the beam shaping body. Referring to Fig. 3 and Fig. 4, the boron neutron capture therapy system 100 is overall arranged in the space of two floors L1 and L2, and the boron neutron capture therapy system 100 also includes irradiation rooms 101 (101A, 101B, 101C) and charged particle beam generation In the room 102 , the patient 200 on the treatment table 40 is treated with neutron beam N irradiation in the irradiation room 101 ( 101A, 101B, 101C). There can be one or more neutron beam generating units 30 to generate one or more therapeutic neutron beams N, and the beam transmission unit 20 can selectively transmit charged particle beams P to one or more neutron beam generating units 30 Alternatively, the charged particle beam P is transmitted to a plurality of neutron beam generating units 30 at the same time, and each neutron beam generating unit 30 corresponds to one irradiation chamber 101 . In this embodiment, there are three neutron beam generating units and three irradiation chambers, which are respectively neutron beam generating units 30A, 30B, and 30C and irradiation chambers 101A, 101B, and 101C. The beam transmission part 20 includes: a first transmission part 21, connected with the accelerator 10; first and second beam direction switchers 22, 23, switching the traveling direction of the charged particle beam P; a second transmission part 24, connected with the first , the second beam direction switcher 22,23; the third, fourth, and fifth transmission parts 25A, 25B, 25C, respectively switch the charged particle beam P from the first beam direction switcher 22 or the second beam direction The neutron beams N are transmitted to the neutron beam generators 30A, 30B, and 30C by the neutron beam generator 23, and the generated neutron beams N are respectively irradiated to patients in the irradiation chambers 101A, 101B, and 101C. The third transmission part 25A is connected to the first beam direction switcher 22 and the neutron beam generation part 30A, the fourth transmission part 25B is connected to the second beam direction switcher 23 and the neutron beam generation part 30B, and the fifth transmission part 25C is connected to The second beam direction switcher 23 and the neutron beam generating unit 30C. That is, the first transmission part 21 is branched into the second transmission part 24 and the third transmission part 25A in the first beam direction switcher 22, and the second transmission part 24 is branched into the second transmission part 23 in the second beam direction switcher 23. The fourth transmission section 25B and the fifth transmission section 25C. The first and second transmission parts 21 and 24 transmit along the X-axis direction, the third transmission part 25A transmits along the Z-axis direction, and the transmission directions of the fourth and fifth transmission parts 25B and 25C are in the XY plane and are in line with the first and the first transmission parts. The transmission direction of the two transmission parts 21, 24 is "Y" shape, and the neutron beam generating parts 30A, 30B, 30C and the corresponding irradiation chambers 101A, 101B, 101C are respectively along the third, fourth, and fifth transmission parts 25A, 25B. , 25C are set in the transmission direction, and the neutron beam N directions generated are respectively the same as the transmission directions of the third, fourth, and fifth transmission parts 25A, 25B, and 25C, so that the neutron beams produced by the neutron beam generation parts 30B, 30C The directions are within the same plane, and the direction of the neutron beam generated by the neutron beam generating unit 30A is perpendicular to the plane. With such an arrangement, the space can be effectively used, and multiple patients can be treated at the same time, without excessively extending the beam transmission line, and the loss is small. It can be understood that the N direction of the neutron beam generated by the neutron beam generating part 30A (30B, 30C) and the transmission direction of the third (fourth, fifth) transmission part 25A (25B, 25C) can also be different; The transmission directions of the two transmission parts 21, 24 can also be different, and the second transmission part 24 can also be canceled, and only has a beam direction switcher, and the beam is branched into 2 and more than 2 transmission parts; the fourth, the fifth The "Y" shape formed by the transmission direction of the transmission parts 25B, 25C and the transmission direction of the first transmission part 21 can also be a deformation of "Y", such as the transmission direction of the fourth transmission part 25B or the fifth transmission part 25C and the first The transmission direction of the first transmission part 21 is the same, the transmission direction of the fourth and fifth transmission parts 25B, 25C and the transmission direction of the first transmission part 21 can also be in other shapes, such as "T" shape or arrow shape, as long as the fourth, fifth The transmission directions of the fifth transmission parts 25B and 25C may form an angle greater than 0 degrees on the XY plane; the transmission directions of the fourth and fifth transmission parts 25B and 25C are not limited to the XY plane, and the transmission direction of the third transmission part 25A is also It may not be along the Z axis, as long as two of the transmission direction of the fourth transmission part 25B, the transmission direction of the fifth transmission part 25C and the transmission direction of the first transmission part 21 are in the same plane (first plane), the first transmission The transmission direction of the part 21 and the transmission direction of the third transmission part 25A are also in the same plane (second plane), and the first plane and the second plane are different; the third transmission part 25A, the neutron beam generating part 30A and the irradiation chamber 101A can also be eliminated so that there is only beam transmission in the XY plane.

The first and second beam direction switchers 22 and 23 include a deflection electromagnet for deflecting the direction of the charged particle beam P and a switch electromagnet for controlling the traveling direction of the charged particle beam P. The boron neutron capture therapy system 100 may also include a beam The collector (not shown) is used to confirm the output of the charged particle beam P before treatment, etc., and the first or second beam direction switcher 22, 23 can make the charged particle beam P deviate from the normal track and guide it to the beam collector .

The first transmission part 21, the second transmission part 24 and the third, fourth, and fifth transmission parts 25A, 25B, and 25C are all made of a transmission pipe C structure, which can be formed by connecting a plurality of sub-transmission parts respectively, and the transmission of a plurality of sub-transmission parts The direction can be the same or different, such as the deflection of the beam transmission direction through the deflection electromagnet, the transmission of the first, second, third, fourth, and fifth transmission parts 21, 24, 25A, 25B, 25C The direction can be the transmission direction of any sub-transmission part, and the first plane and the second plane formed above are the planes formed between the sub-transmission parts directly connected to the beam direction switcher; A beam adjustment unit (not shown) of the beam P, the beam adjustment unit includes a horizontal deflector and a horizontal vertical deflector for adjusting the axis of the charged particle beam P, and a quadrupole for suppressing the divergence of the charged particle beam P. An electromagnet, and a four-way cutter for shaping the charged particle beam P, etc. The third, fourth, and fifth transfer units 25A, 25B, and 25C may include a current monitor (not shown) and a charged particle beam scanning unit (not shown) as needed. The current monitor measures the current value (that is, charge, irradiation dose rate) of the charged particle beam P irradiated on the target T in real time. The charged particle beam scanning unit scans the charged particle beam P to perform irradiation control of the charged particle beam P on the target T, such as controlling the irradiation position of the charged particle beam P on the target T.

The charged particle beam generating chamber 102 may include an accelerator chamber 1021 and a beam transmission chamber 1022, the accelerator chamber 1021 has two layers, and the accelerator 10 extends from L2 to L1. The beam transmission chamber 1022 is located at L2, and the first transmission part 21 extends from the accelerator chamber 1021 to the beam transmission chamber 1022 . The irradiation chambers 101B and 101C are located in L2, and the irradiation chamber 101A is located in L1. In this embodiment, L1 is below L2, that is, the floor of L2 is the ceiling of L1. It can be understood that the opposite configuration can also be used. The material of the floor (ceiling) S can be concrete or boron-containing barite concrete with a thickness of more than 0.5m. The irradiation chambers 101A, 101B, 101C and the beam transmission chamber 1022 have a shielding space surrounded by a shielding wall W1. The shielding wall W1 can be a wall made of boron-containing barite concrete with a thickness of more than 1m and a density of 3g/c.c. The first partition shielding wall W2 separating the beam transmission chamber 1022 from the irradiation chambers 101B and 101C, the second partition shielding wall W3 separating the accelerator chamber 1021 and the beam transmission chamber 1022 at L1, and the accelerator chamber 1021 and the irradiation chamber 101A at L2 The third partition shielding wall W4. The accelerator chamber 1021 is surrounded by a concrete wall W having a thickness of 1 m or more, the second partition shielding wall W3 , and the third partition shielding wall W4 . At least a part of the neutron beam generating parts 30B, 30C is embedded in the first partition shielding wall W2, and the fourth and fifth transmission parts 25B, 25C extend from the beam transmission chamber 1022 to the neutron beam generating parts 30B, 30C; The beam generation part 30A is located in the irradiation chamber 101A, and the third transmission part 25A extends from the beam transmission chamber 1022 through the floor S to the irradiation chamber 101A. The irradiation rooms 101A, 101B, and 101C respectively have screen doors D1, D2, and D3 for the treatment table 40 and doctors to enter and exit. The accelerator room 1021 has screen doors D4, D5 for entering and leaving the accelerator room 1021 at L1 and L2 to maintain the accelerator 10, respectively. The beam transmission chamber 1022 has a shield door D6 for entering and exiting the beam transmission chamber 1022 from the accelerator chamber 1021 to maintain the beam transmission part 20 , and the shield door D6 is arranged on the second partition shielding wall W3 . The irradiation chambers 101A, 101B, and 101C also have inner shielding walls W5 to form labyrinth-shaped passages from the shielding doors D1, D2, D3 to the beam outlets, preventing the radiation from being directly transmitted when the shielding doors D1, D2, and D3 are accidentally opened. For irradiation, the inner shielding wall W5 can be arranged in different positions according to the different layouts of the irradiation chamber, and the shielding door D7 inside the irradiation chamber can also be arranged between the inner shielding wall W5 and the shielding wall W1 or the third partition shielding wall W4, forming a Secondary protection during neutron beam irradiation therapy. The inner shielding wall W5 can be made of boron-containing barite concrete wall with a thickness of more than 0.5m and a density of 3g/c.c.; the shielding doors D1, D2, D3, D4, D5, D6, and D7 can be composed of two independent main shielding doors D and the secondary screen door D' or only the main screen door D or the secondary screen door D' can be determined according to the actual situation. The main screen door D can be made of the same material with a thickness of more than 0.5m and a density of 6g/c.c. Boron-containing PE or barite concrete or lead, the secondary screen door D' can be boron-containing PE or barite concrete or lead of the same material with a thickness of more than 0.2m and a density of 6g/c.c. In this embodiment, the shielded doors D1, D4, D5, and D6 are composed of the main shielded door D and the secondary shielded door D', the shielded doors D1, D2, and D3 only include the main shielded door D, and the shielded door D7 only includes the secondary shielded door D '. The shielding wall and the shielding door form a shielding space, and suppress radiation from entering the room from the outside of the irradiation rooms 101A, 101B, 101C and beam transmission room 1022 and radiation from the room to the outside. In this embodiment, the second partition shielding wall W3 separating the accelerator chamber 1021 and the beam transmission chamber 1022 is arranged between the accelerator 10 and the first beam direction switcher 22, that is, the first transmission part 21 passes through the second partition The shielding wall W3, it can be understood that the second partition shielding wall W3 and the shielding door D6 can be canceled, and can also be arranged in other positions, such as between the first and second beam direction switchers 22, 23 or the second beam direction switch Between the device 23 and the neutron beam generating part 30B, 30C; or between the second partition shielding wall W3 and the first partition shielding wall W2, an additional partition shielding wall and a shield door are provided. That is to say, a shielding wall is set between the neutron beam generating part and the accelerator, and the operator is protected from neutrons and other radiation leaked from the neutron beam generating part during the inspection and maintenance of the accelerator. activated response.

Referring to FIG. 5 , the beam shaper 31 is supported by the support module 60 arranged in the partition wall 103 (the first partition shielding wall W2 ), and the support module 60 is at least partially accommodated on the side of the partition wall 103 close to the irradiation chamber 101 The receiving groove 1031 of the charged particle beam generation chamber 102 is provided with a groove 1032 for the passage of the transmission tube of the accelerator, so that the receiving groove 1031 and the groove 1032 penetrate the partition wall in the neutron beam N transmission direction, this embodiment Among them, the wall surface of the partition wall 103 is a plane, and the transmission direction of the neutron beam N is perpendicular to the wall surface of the partition wall 103 . The modularization of the supporting structure enables the beam shaping body to be locally adjusted to meet the accuracy requirements, improve the beam quality and meet the assembly tolerance of the target. On a plane perpendicular to the transmission direction of the neutron beam N, the cross-sectional profile of the support module 60 is located between the cross-sectional profiles of the receiving groove 1031 and the groove 1032, thereby avoiding the occurrence of through cracks in the beam transmission direction and further reducing radiation , and it is convenient to adjust the support module 60 at the same time. In this embodiment, the support module 60 is a rectangular parallelepiped as a whole, and the cross sections of the accommodation groove 1031 and the groove 1032 perpendicular to the neutron beam N transmission direction are both "Xi" shaped, and the side walls of the accommodation groove 1031 and the groove 1032 are parallel to the neutron beam N. Beam N transmission direction. The side of the partition wall 103 close to the irradiation room 101 is also provided with a shielding plate 1033. 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 radiation to normal tissues of the patient. On a plane perpendicular to the transmission direction of the neutron beam N, the shielding plate 1033 can match the cross-sectional profile of the supporting module 60 , so as to shield neutrons leaking from between the supporting module and the partition wall. The shielding plate is a PE plate. It can be understood that the side of the partition wall 103 close to the charged particle beam generating chamber 102 and the side of the support module 60 close to the irradiation chamber 101 can also be provided with a shielding plate, and the shielding plate can be made of other neutrons such as lead or The photon shielding material is formed, and the shielding plate may not be provided.

The emission directions of neutrons produced by the interaction between the charged particle beam P and the target T are almost uniformly distributed in space, and at the same time, a large number of recoil neutrons will be generated during the "shaping" process of the neutrons by the beam shaping body 31. Recoil neutrons are an important consideration in radiation shielding design. Closed shielding cannot be achieved where the shielding wall or floor is passed by components or elements, which may easily cause leakage of neutrons and other radiation. The shielding wall W2, the first transmission part 21 pass through the second partition shielding wall W3, the third transmission part 25A passes through the floor S, and the first partition shielding wall W2, the second partition shielding wall W3, and the floor S face the beam transmission direction The first shielding body 70 , the second shielding body 80 and the third shielding body 90 can be provided at the upstream side where the neutron beam generating parts 30B, 30C, the first transmission part 21 and the third transmission part 25A pass through. The first shielding body 70 covers the ends of the neutron beam generating parts 30B and 30C facing the accelerator, preventing the neutrons overflowing or reflected from the beam shaping body of the neutron beam generating parts 30B and 30C from entering the accelerator chamber 1021 and the beam transmission chamber 1022 , the fourth and fifth transmission parts 25B and 25C pass through the first shielding body 70 to reach the targets T of the neutron beam generating parts 30B and 30C. The second shielding body 80 prevents neutrons overflowing or reflecting from the beam transmission part 20 from entering the accelerator chamber 1021, and the first transmission part 21 passes through the second shielding body 80 and the second partition shielding wall W3 to reach the first beam direction switcher twenty two. 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 part 25A passes through the third shield 90 and the floor S to reach the neutron beam generating part 30A. The material of the first shielding body 70 , the second shielding body 80 and the third shielding body 90 may be boron-containing PE or barite concrete or lead, and may also include other neutron shielding materials.

The first, second and third shielding bodies 70 , 80 , and 90 will be described in detail below by taking the first shielding body 70 as an example. In one embodiment, the first shielding body 70 is movable, and is movably installed on the upstream side of the first partitioned shielding wall W2 toward the beam transmission direction (the side close to the charged particle beam generating chamber 102) through the installation mechanism 70A. ), and has a first position and a second position. In the first position, the receiving hole 71 through which the fourth and fifth transmission parts 25B, 25C pass is formed, and covers the ends of the neutron beam generating parts 30B, 30C facing the accelerator 10, shields the recoil neutrons, and limits the neutron dose area, protect the accelerator components, reduce the radiation damage of the components, reduce the element activation of the accelerator components, and at the same time, when one irradiation room is running, protect the other irradiation room to ensure that the radiation dose of the non-operating irradiation room is at a safe level; in the second position, the receiving hole 71 is opened, exposing the end of the neutron beam generating part 30B, 30C facing the accelerator 10, without removing the transfer tube C passing through the receiving hole 71, an operation space is formed, and the neutron beam can be replaced when the accelerator 10 is closed The generation parts 30B, 30C, such as the target T, the beam shaping body 31, the radiation detection components or the first and second cooling pipes 3012, 3013 arranged in the beam shaping body 31, can also be replaced by removing part of the transmission pipes. out of space, or install, debug, and maintain the beam transmission part 20 passing through the first partition shielding wall W2 and the first shielding body 70 . The accommodating holes can accommodate the transmission pipes C, magnets, etc. of the fourth and fifth transmission parts 25B and 25C, and can also accommodate the first and second cooling pipes 3012, 3013 or other functional components, which can facilitate movement and provide operation space without disturbing Non-movable component of the beam delivery section. The first shielding body 70 and the first partitioning shielding wall W2 may be in airtight contact to enhance the shielding effect, or there may be a gap, and the shielding effect may be realized by adjusting the size of the first shielding body 70 .

As shown in Fig. 6 and Fig. 7, in this embodiment, the first shielding body 70 includes a first shielding part 72 and a second shielding part 73, and the first shielding part 72 and the second shielding part 73 are respectively along the neutron beam generating The first and second directions L1 and L2 of the parts 30B and 30C move to the first position, the first shielding part 72 and the second shielding part 73 respectively have first and second grooves 721 and 731, and the first and second grooves The slots 721, 731 jointly form the receiving hole 71 through which the fourth and fifth transmission parts 25B, 25C pass through at the first position, and cover the ends of the neutron beam generating parts 30B, 30C facing the accelerator 10; the first shielding part 72 and The second shielding part 73 moves to the second position along the third and fourth directions L3 and L4 away from the neutron beam generating parts 30B and 30C, respectively. In the second position, the receiving hole 71 is opened to expose the neutron beam generating parts 30B, 30C, 30C is toward the end of the accelerator 10 , and an operation space is formed without removing the transfer pipe C passing through the accommodation hole 71 . It can be understood that the first shielding body 70 may also include a third shielding portion or be composed of more than three shielding portions.

In this embodiment, the first shielding part 72 and the second shielding part 73 are sliding, and the guide rail 74 and the rollers 75 fixed on the first and second shielding parts 72, 73 constitute the sliding assembly of the first shielding body 70 (installation mechanism 70A), the roller 75 rolls along the guide rail 74 to drive the first and second shielding parts 72, 73 to slide along the guide rail 74, and the guide rail 74 is fixed on the side of the first partition shielding wall W2 facing the charged particle beam generating chamber 102 and extends in the direction Parallel to the ground (XY plane), that is, the first and second shielding parts 72 and 73 are configured as horizontal double-opening sliding doors. It can be understood that the installation mechanism 70A can have other settings, and can also be moved by other means, such as rotation, etc. .

As shown in Figure 8, in another embodiment, the installation mechanism 70A' includes a guide rail 701a (74') and a roller 702a (75'), and the guide rail 701a is directly fixed on the first partition shielding wall W2 through expansion screws, referring to Figure 9 As shown in Figure 11b, the roller 702a is connected to the connecting plate 704a fixed to the first and second shielding parts 72, 73 through the first connecting member 703a (such as a bolt and nut). Specifically, the roller 702a is rotatably arranged around its central axis One end of the bolt (such as through a bearing), and the other end of the bolt passes through the connecting plate 704a and is tightened on both sides of the connecting plate 704a through a nut. It can be understood that the guide rail 701a and the roller 702a can also have other fixing methods. The installation mechanism 70A' also includes a frame, which includes a first frame 705a1 and a second frame 705a2 for fixing the first and second shielding parts 72, 73 (wherein, the structure and function of the second frame are the same as those of the first frame, not shown in the figure). shown), the first and second shielding parts 72 and 73 are both constructed of multiple boards, and the multiple boards are spliced together and fixed to the first frame 705a1 and the second frame 705a2 of the first and second shielding parts 72 and 73 respectively , the connecting plate 704a is fixed on the top of the frame to form a suspension rail. Referring to Fig. 10, the bottom of the frame can also be fixed with a chute 706a, and the chute 706a cooperates with the wheel 707a fixed on the shielding wall W2 to form an auxiliary limit for the horizontal sliding of the first and second shielding parts 72, 73 along the guide rail 701a, Prevent the first and second shielding parts 72, 73 and their first frame 705a1 and second frame 705a2 from turning over in a direction perpendicular to the shielding wall W2. The frame is constructed of aluminum alloy profiles, and the radioactive half-life of the product after being irradiated by neutrons is relatively short, which reduces the secondary radiation generated. The first and second shielding parts 72 and 73 are boron-containing PE plates. It is understandable that the frame can also use Other neutron-irradiated products are non-radioactive or neutron-irradiated products have low radioactivity, or neutron-irradiated radioactive isotopes have a short half-life. The first and second shielding parts 72 and 73 can also be Use other neutron shielding materials.

The neutron capture therapy system 100 may also include a driving mechanism 70B of the first shielding body 70, the driving mechanism 70B drives the movement of the first shielding body 70, and the driving mechanism 70B includes a cylinder 701b, a connecting rod 702b, a chain 703b, a sprocket 704b, a connection Block 705b. The cylinder body of the cylinder 701b is supplied with air through the air supply device (not shown in the figure) to drive the piston movement of the cylinder 701b, and the piston of the cylinder 701b is connected to the first frame 705a1 of the first shielding part 72 through the connecting rod 702b, thereby driving the first shielding Part 72 moves, specifically, the piston moves in the horizontal direction, one end of the piston of the cylinder 701b extends into the cylinder body of the cylinder 701b, and the other end is connected with the connecting rod 702b, and the connecting rod 702b is fixed to the first frame 705a1 of the first shielding part 72 away from The side of the second shielding part 73; the chain 703b is located on both sides of the sprocket 704b and is connected to the first frame 705a1 and the second frame 705a2 of the first and second shielding parts 72 and 73 respectively through the connecting block 705b, and the first shielding part 72 moves through the chain 703b to drive the second shielding part 73 to move in the opposite direction, thereby reaching the first position or the second position. Specifically, one end of the connecting block 705b is fixed to the top of the frame 705a, and the other end is connected to the chain 703b through the tooth clip combine. It can be understood that in this embodiment, the connecting rod 702b, the chain 703b, the sprocket 704b, and the connecting block 705b constitute the transmission member of the drive mechanism 70B, and the transmission member is connected with the piston of the cylinder 701b. It can be understood that the transmission member can also have other Setting; a buffer member 706b can also be provided. When the first shielding part 72 is about to move to the end position in a direction away from the second shielding part 73, the connecting rod 702b contacts the buffer member 706b to prevent impact caused by collision; a stop member can also be provided 707b (such as a fixed screw), the stop member 707b acts on the connecting rod 702b to limit the maximum distance that the first shielding part 72 moves away from the second shielding part 73; there can also be other driving methods, such as driving through a motor The first or second shield moves. The driving mechanism 70B also includes a fixed bracket 708b, which is fixed on the shielding wall W2 through the second connecting piece 709b (as shown in Figure 11d). 706b, stop member 707b) can be fixed on the fixing bracket 708b.

The neutron capture therapy system 100 can also control the operation of the driving mechanism 70B through a control mechanism (not shown in the figure), thereby controlling the movement of the first shielding body 70. The control mechanism can be arranged outside the charged particle beam generating room 102, such as a control room (as described below) to prevent the control mechanism from being disabled by neutron activation.

Each component of the installation mechanism 70A, 70A' or the driving mechanism 70B can be made of products that are not radioactive after being irradiated by neutrons, or have low radioactive activity after being irradiated by neutrons, or produce radioactive isotopes with short half-lives after being irradiated by neutrons. materials, such as aluminum alloy, but due to the requirements of mechanical properties, some components in this embodiment are still made of steel, such as the components carrying the driving force (such as the cylinder body of the cylinder 701b), the connection carrying the first shielding body 70 (first connecting piece 703a), and the connecting piece (second connecting piece 709b) carrying the driving mechanism 70B. After the steel material is irradiated by neutrons, it will produce radioactive isotopes with long half-lives, such as cobalt 60. A neutron shielding structure 70C is required to carry out Shielding, reducing the secondary radiation generated by the installation mechanism or driving mechanism after being irradiated by neutrons. As shown in Fig. 11a, a collar 701c is provided on the outer periphery of the cylinder 701b. As shown in Figure 11b, a cap 702c is provided outside the first connecting piece 703a, and the cap 702c covers the part of the first connecting piece 703a protruding from the connecting plate 704a at one end passing through the connecting plate 704a (nuts and bolts pass through the connecting plate 704a The end of the connecting plate 704a); the collar 703c can also be set to cover other exposed parts of the first connecting piece 703a, such as the part where the bolt passes through the connecting plate 704a and is located in the middle of the two side plates of the connecting plate 704a (the first connecting piece and the connecting plate overlapped and exposed part), the part between the roller 702a and the connecting plate 704a, it can be understood that the part where the bolt passes through the connecting plate 704a and is located in the middle of the two side plates of the connecting plate 704a due to space constraints, as shown in Figure 11c, also The collar 703c' may cover the bolt from the outside of the web 704a. As shown in the Z-direction schematic diagram of Figure 11d, without affecting the connection relationship of the mechanism, the cover body 705c can also be integrally covered outside the connecting plate 704a to connect the connecting plate 704a and the first connecting piece 703a passing through the connecting plate 704a. For shielding, the cover body 705c may be in the shape of a ⊐, surrounding the connection plate 704a above the frame 705a and the first connection piece 703a passing through the connection plate 704a, it can be understood that the cover body 705c may also include a top covered by the neutron shielding The larger the area, the better the secondary radiation shielding effect of the installation mechanism after neutron radiation.

As shown in Figure 11e, a baffle 704c is provided outside the second connecting piece 709b, and the baffle 704c is fixed on the fixed bracket 708b. The upstream side of the beam propagation direction (the side close to the charged particle beam generating chamber 102 ) shields recoil neutrons. In another embodiment, as shown in Figure 11f, the baffle 704c' is in the shape of "⊐", on the upper side, the lower side and the side facing the upstream of the beam transmission direction of the second connecting piece 709b (near the charged particle beam generating One side of chamber 102) shields recoil neutrons. It can be understood that the baffles 704c and 704c' may also include side parts to form a circumferential seal and enhance the radiation shielding effect. As shown in Fig. 11g, the baffle 704c' also covers the side part of the second connecting member 709b.

The material of the neutron shielding structure 70C can include boron-containing resin, boron-containing glass fiber composite material, etc. It can be understood that the form and position of the neutron shielding structure 70C can also be set according to specific needs.

The first and second beam direction switchers 22 and 23 are respectively surrounded by shielding covers 26 to prevent leakage of neutrons and other radiation from the beam direction switchers. The material of the shielding covers 26 can be boron-containing PE or barite concrete or lead. It can be understood that the first and second beam direction switchers 22, 23 can also be surrounded by a shield 26 as a whole; other parts of the beam transmission part, such as vacuum tubes, can also be surrounded by a shield to prevent neutrons and other radiation The wire leaks from the beam delivery section.

The boron neutron capture therapy system 100 may also include a preparation room, a control room and other spaces for auxiliary treatment. Each irradiation room may be configured with a preparation room for fixing the patient to the treatment table, injecting boron medicine, For preparations such as treatment plan simulation, a connection channel is set between the preparation room and the irradiation room. After the preparation is completed, the patient is directly pushed into the irradiation room or automatically entered into the irradiation room by the control mechanism through the track. The preparation room and the connection channel are also shielded The walls are closed and the preparation room also has a screened door. The control room is used to control the accelerator, beam transmission unit, treatment table, etc., to control and manage the entire irradiation process. Managers can also monitor multiple irradiation rooms at the same time in the control room.

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

Although the illustrative specific embodiments of the present invention have been described above, so that those skilled in the art can understand the present invention, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those of ordinary skill in the art, As long as various changes are within the spirit and scope of the present invention defined and determined by the appended patent scope, these changes are obvious and all fall within the scope of protection of the present invention.

100: Neutron capture therapy system 10: Accelerator 101, 101A, 101B, 101C: irradiation room 102: Charged particle beam generation chamber 1021: Accelerator room 1022: Beam Delivery Chamber 103: Partition wall 1031: storage tank 1032: Slot 1033: shielding plate 20: Beam transmission part 21,24,25A,25B,25C: transmission department 22,23: Beam Direction Switcher 26: shielding cover 30, 30A, 30B, 30C: Neutron Beam Generation Department 301: heat dissipation layer 3011: cooling channel 3012,3013: cooling pipe 302: base layer 303: Action layer 304: anti-oxidation layer 31: Beam Shaper 311: reflector 312: retarder 313: thermal neutron absorber 314: radiation shield 315: Beam exit 32: Collimator 40: Treatment Table 50: Radiation shielding device 60: Support module 70: The first shield 70A, 70A’: Mounting mechanism 70B: Driving mechanism 70C: Neutron shielding structure 703a: first connector 704a: connecting plate 705a: frame 705a1: First frame 705a2: Second frame 706a: Chute 707a: Wheels 701b: Cylinder 702b: Connecting rod 703b: chain 704b: sprocket 705b: Connection block 706b: cushioning member 707b: stop member 708b: Fixed bracket 709b: second connector 701c: Collar 702c: hat cover 703c: Collar 703c': Collar 704c: Baffle 704c': Baffle 705c: cover body 71:Accommodating hole 72: The first shielding part 721,731: Groove 73: The second shielding part 74,701a: guide rail 75,702a: Roller 80:Second shield 90: The third shield 200: Patient C: transfer tube D: Main screen door D': secondary screen door D1, D2, D3, D4, D5, D6, D7: shielded doors L1, L2: floors L1, L2: direction L3, L4: direction M: Tumor cells N: neutron beam P: charged particle beam S: floor T: Target W: concrete wall W1: shielding wall W2: The first partition shielding wall W3: Second partition shielding wall W4: The third partition shielding wall W5: inner shielding wall

Fig. 1 is a schematic structural diagram of a neutron capture therapy system in an embodiment of the present invention; Fig. 2 is a schematic diagram of the target structure of the neutron capture therapy system in the embodiment of the present invention; 3 is a schematic layout diagram of the neutron capture therapy system in the embodiment of the present invention on the XY plane; Fig. 4 is the schematic diagram of Fig. 3 in section A-A; 5 is a schematic diagram of the installation of the beam shaper support module of the neutron capture therapy system in the embodiment of the present invention; Fig. 6 is a schematic structural view of the shielding body provided at the position where the neutron beam generating part passes through the shielding wall of the neutron capture therapy system in an embodiment of the present invention; Fig. 7 is a schematic diagram of another state of the shielding body in Fig. 6; Fig. 8 is a schematic structural view of the shielding body provided at the position where the neutron beam generating part of the neutron capture therapy system passes through the shielding wall in another embodiment of the present invention; Fig. 9 is a partially enlarged schematic diagram of another state of the installation mechanism and the drive mechanism of the shielding body in Fig. 8; Fig. 10 is a partially enlarged schematic diagram of the installation mechanism of the shielding body in Fig. 8; 11a to 11g are schematic diagrams of the neutron shielding structure of the installation mechanism and the driving mechanism of the shielding body in FIG. 8 .

100: Neutron capture therapy system

10: Accelerator

20: Beam transmission part

30: Neutron beam generation department

3012,3013: cooling pipe

31: Beam Shaper

311: reflector

312: retarder

313: thermal neutron absorber

314: radiation shield

315: Beam exit

32: Collimator

40: Treatment Table

50: Radiation shielding device

200: Patient

C: transfer tube

M: Tumor cells

N: neutron beam

P: charged particle beam

T: Target

Claims (10)

A neutron capture therapy system, comprising an accelerator, a beam transmission part, and a neutron beam generation part, the accelerator accelerates charged particles to generate a charged particle beam, and the beam transmission part transmits the charged particle beam generated by the accelerator To the neutron beam generating part, the neutron beam generating part generates a therapeutic neutron beam, wherein the neutron capture therapy system also includes a The shielding wall of the space, a shielding body is arranged on the side of the shielding wall facing the upstream side of the beam transmission direction and the part passed by the beam transmission part or the neutron beam generation part, the neutron capture therapy system It also includes a mounting mechanism or a driving mechanism of the shielding body, the mounting mechanism is used to movably install the shielding body on the side of the shielding wall facing the upstream of the beam transmission direction, and the driving mechanism is used to drive The shielding body moves, and the installation mechanism is provided with a first neutron shielding structure or the driving mechanism is provided with a second neutron shielding structure. The neutron capture therapy system according to claim 1, wherein the installation mechanism includes a first connecting piece carrying the shielding body, and the first neutron shielding structure covers an exposed part of the first connecting piece. The neutron capture therapy system according to claim 2, wherein the installation mechanism includes guide rails and rollers, the guide rails are fixed on the side of the shielding wall facing the upstream side of the beam transmission direction, and the rollers penetrate through the first A connecting piece is fixed on the shielding body, and the shielding body can slide along the guide rail through the rollers. The neutron capture therapy system according to claim 3, wherein the installation mechanism includes a frame, the shielding body is a plate fixed to the frame, a connecting plate is fixed on the top of the frame, and the rollers pass through the The first link is fixed to the link plate. The neutron capture therapy system according to claim 1, wherein the driving mechanism includes a fixed bracket and a second connecting piece carrying the driving mechanism, and the fixing bracket is fixedly mounted to the shielding wall through the second connecting piece , the second neutron shielding structure includes a baffle that shields the second connecting member. The neutron capture therapy system according to claim 1, wherein the driving mechanism further includes a cylinder, the cylinder includes a cylinder body, and the second neutron shielding structure includes a collar covering the periphery of the cylinder body. The neutron capture therapy system according to claim 6, wherein the cylinder body is fixed to the shielding wall, the cylinder further includes a piston, one end of the piston extends into the cylinder body, and the other end of the piston One end is connected to the shielding body. The neutron capture therapy system according to claim 7, wherein the driving mechanism further includes a transmission member connected to the piston, the shielding body includes a first shielding part and a second shielding part, and the first shielding The part and the second shielding part move in opposite directions driven by the cylinder and the transmission member. The neutron capture therapy system according to claim 8, wherein the transmission member includes a sprocket and chains on both sides of the sprocket, and the chains on both sides of the sprocket are respectively connected to the first shielding part and the second shielding part. The neutron capture therapy system according to Claim 1, wherein the material of the first and second neutron shielding structures is boron-containing resin or boron-containing glass fiber composite material.

Images