Flash therapeutic system, radiation shielding protection method, and related device

Abstract

Provided in the present application are a FLASH therapeutic system, a radiation shielding protection method and a related device. The related device comprises a shielding chamber, the shielding chamber having an accommodation cavity, and a first window and a second window which are sequentially arranged at intervals in a beam current direction on the shielding chamber; the center point of the first window, the center point of the second window and the central axis of a beam current are located on the same straight line; the first window and the second window are separately communicated with the accommodation cavity; the first window is used for a beam current to enter and is smaller than the second window; the second window is used for allowing a target subject to pass through such that the target subject is accommodated in the accommodation cavity; the second window is arranged to be close to a radiation shielding wall of a therapeutic room; and the geometric center point of the accommodation cavity is arranged at a Bragg peak position of the beam current. The present application can satisfy radiation protection requirements of large-beam-current FLASH radiotherapy and further can satisfy the function of positioning an isocenter point, and also involves reduced occupied area and infrastructure construction cost.

Description

FLASH treatment system, radiation protection shielding method and related devices

[0001] This application claims priority to Chinese Patent Application No. CN202311122794.4 filed on September 1, 2023, which is incorporated by reference in its entirety. Technical Field

[0002] The present application relates to the technical fields of proton accelerators and tumor radiotherapy, for example, to FLASH treatment systems, radiation protection shielding methods and related devices. Background Art

[0003] Proton tumor therapy technology is currently the most advanced, mature and high-end medical technology in the world, and is one of the main means of tumor treatment. Compared with the currently widely used high-energy neutrons and electrons, protons can more effectively concentrate the energy of rays on the tumor target area to be treated, improve the local control rate of tumors, and greatly reduce radiation complications of normal organs and tissues. Proton therapy devices have become the mainstream equipment for tumor radiotherapy in the world.

[0004] FLASH therapy primarily involves delivering a dose to the entire treatment volume in less than a second. Early preclinical evidence suggests that these extremely high dose rates significantly protect healthy tissue without reducing damage to cancer cells compared to conventional radiotherapy. Because FLASH's large beam delivers a very high dose in a very short period of time, it places high demands on radiation shielding walls. In other words, the facility where FLASH radiotherapy is performed must have sufficient radiation shielding capabilities. This requires sufficiently thick radiation shielding walls, which occupy a large area and require significant capital investment.

[0005] Based on this, the present application provides a FLASH treatment system, a radiation protection shielding method and related devices to improve related technologies.

[0006] Summary of the Invention

[0007] The purpose of this application is to provide a FLASH treatment system, a radiation protection shielding method and related devices, which can not only meet the radiation protection requirements of large-beam FLASH radiotherapy, but also meet the function of locating the isocenter, reducing the floor space and infrastructure costs.

[0008] The purpose of this application is achieved by the following technical solutions:

[0009] In the first aspect, the present application provides a shielding chamber for radiation protection, wherein the shielding chamber has a accommodating cavity and a first window and a second window arranged on the shielding chamber and arranged in sequence along the beam direction, the center point of the first window and the center point of the second window are located on the same straight line with the central axis of the beam, the first window and the second window are respectively connected to the accommodating cavity, the first window is used for the beam to enter and is smaller than the second window, the second window is used for the target object to pass through and be accommodated in the accommodating cavity, the second window is set to be close to the radiation shielding wall of the treatment room, and the geometric center point of the accommodating cavity is set to the Bragg peak position of the beam.

[0010] The beneficial effect of this technical solution is that traditionally, in order to meet the radiation shielding requirements, FLASH radiotherapy requires the construction of thick radiation shielding walls, resulting in high capital investment and increased floor space. This application saves space and cost by providing a shielding chamber, eliminating the need to build overly thick fixed shielding walls.

[0011] In a possible implementation, the shielding chamber is a stacked structure that is sequentially arranged from the inside out in a spiral installation, and the shielding chamber includes a proton shielding layer and a neutron shielding layer that are sequentially arranged from the inside out.

[0012] The beneficial effect of this technical solution is that the shielding chamber adopts a detachable stacked structure, which can be spliced ​​into proton shielding layers and neutron shielding layers of different thicknesses according to the dose, meeting the radiation protection requirements in different application scenarios.

[0013] In a possible implementation, the proton shielding layer includes M proton shielding units stacked from the inside out, and the neutron shielding layer includes N neutron shielding units stacked from the inside out, where M and N are both positive integers.

[0014] The beneficial effects of this technical solution are that the proton and neutron shielding layers are composed of multiple stacked shielding units, allowing the number of shielding units to be increased without increasing the overall thickness of the shielding chamber. Each shielding unit effectively absorbs and reduces radiation penetration, further reducing the radiation level in the external environment. Each shielding unit is independently removable, allowing the number of shielding units to be flexibly selected, increased, or decreased according to specific circumstances to meet the radiation shielding requirements of different application scenarios, allowing the radiation protection shielding equipment to adapt to different treatment doses and radiation sources.

[0015] In a possible implementation, the material of the proton shielding unit includes one or more of the following: stainless steel, lead, aluminum, and concrete; the material of the neutron shielding unit includes one or more of the following: polyethylene, polypropylene, polystyrene, polyester, boron, lead, tungsten, iron, and barium.

[0016] The beneficial effects of this technical solution are that the proton shielding unit can be made of materials such as stainless steel, lead, aluminum, and concrete, and the neutron shielding unit can be made of materials such as polyethylene, polypropylene, polystyrene, polyester, boron, lead, tungsten, iron, and barium. These materials are low-cost and easy to obtain, and can reduce the manufacturing cost and maintenance cost of radiation protection shielding equipment while meeting radiation shielding requirements.

[0017] In one possible implementation, M=N=5.

[0018] The beneficial effect of this technical solution is that the number of shielding units of the proton shielding layer and the neutron shielding layer can be the same. By setting up 5 layers of shielding units, the volume and weight of the entire shielding chamber can be reduced while meeting the radiation shielding requirements. On the one hand, it is easy to disassemble, and on the other hand, it is easy to adjust the position of the shielding chamber by the mobile device.

[0019] In a possible implementation, a positioning mark is provided at the center of the first window, and the positioning mark is used to indicate the center point of the first window. The first window and the second window are located on opposite sides of the shielding chamber.

[0020] The beneficial effect of this technical solution is that by setting a positioning mark, the operator can accurately determine the position of the center point of the first window and ensure that it is aligned with the isocenter of the beam, which helps to ensure that the beam is accurately delivered to the target object and improve the accuracy of the test or treatment.

[0021] In a second aspect, the present application provides a radiation protection shielding device, which includes any of the above-mentioned shielding chambers and a moving device, wherein the moving device is used to adjust the position of the shielding chamber so that the center point of the first window is aligned with the isocenter of the beam.

[0022] By using a mobile device to align the center of the first window of the shielding chamber with the isocenter of the beam, it is possible to ensure that the beam is accurately delivered to the tumor area of ​​the target object, thereby improving the accuracy of FLASH radiotherapy. After the large-beam FLASH radiotherapy is completed, the shielding chamber can be moved to other storage locations by the mobile device, thereby avoiding the problem of adding radiation shielding walls to the proton accelerator room in order to carry out large-beam FLASH radiotherapy. Under the premise of flexible operation, a huge amount of infrastructure economic costs and floor space costs are saved. In summary, the present application can meet the radiation protection requirements of large-beam FLASH radiotherapy, and can also meet the function of locating the isocenter, thereby reducing floor space and infrastructure costs.

[0023] In a possible implementation, the mobile device includes:

[0024] A workbench, used for carrying the shielding chamber and driving the shielding chamber to perform lifting motion;

[0025] The driving module is used to provide lifting power for the workbench.

[0026] The beneficial effect of this technical solution is that the position of the shielding chamber can be flexibly adjusted by using the workbench and drive module in combination. Compared with traditional fixed radiation shielding walls, the use of a mobile device saves space. The lifting and lowering movement of the workbench can adjust the position of the shielding chamber without requiring excessive floor space.

[0027] In a possible implementation, the moving device adopts a hydraulic scissor lift, the driving module includes a hydraulic cylinder and a hydraulic unit, and the moving device also includes a travel switch and a hydraulic handle.

[0028] The beneficial effect of this technical solution lies in the fact that the hydraulic scissor lift provides stable lifting motion, ensuring that the shielding chamber remains stable during adjustment, avoiding unnecessary vibration and shaking. Specifically, the drive module uses a hydraulic cylinder and hydraulic unit to precisely control the speed and position of the lifting motion, making the shielding chamber's lifting and adjustment more accurate and controllable. By providing a travel switch and hydraulic handle, the operator can control the lifting motion through the travel switch and hydraulic handle, making the adjustment process more convenient and efficient.

[0029] In a possible implementation, the moving device further includes a planar moving component disposed on an upper surface of the workbench, and the planar moving component is used to change a position of the shielding compartment on the workbench.

[0030] The planar moving component is a ball screw module, the first window and the second window are located on opposite sides of the shielding chamber, and the workbench is connected to the shielding chamber through the ball screw module so that the shielding chamber moves back and forth along the beam movement direction.

[0031] The beneficial effect of this technical solution is that by setting up a ball screw module, the shielding chamber can be moved back and forth along the direction of beam movement. The ball screw module can provide precise linear motion to ensure that the position adjustment of the shielding chamber is more accurate.

[0032] In a possible implementation, the ball screw module is provided with a hand wheel and a screw rod;

[0033] The bottom of the shielding bin is slidably arranged on the guide rail on the upper surface of the workbench. Two first screw rod seats are provided on the upper surface of the workbench. A second screw rod seat is provided at the bottom of the shielding bin. One end of the screw rod is connected to the handwheel, and the other end of the screw rod passes through the screw holes on one of the first screw rod seat and the second screw rod seat in sequence and is connected to the other first screw rod seat.

[0034] The beneficial effect of this technical solution is that the handwheel, as a control device, provides an intuitive operation method. The operator can turn the handwheel to control the movement of the shielding chamber, which is simple and clear. Specifically, the handwheel controls the ball screw module, and the distance the shielding chamber moves forward and backward is controlled according to the rotation angle. This precise control method allows the operator to accurately adjust the position of the shielding chamber. Moreover, the handwheel control method makes the adjustment process responsive and meets the immediate needs of treatment or testing.

[0035] In a possible implementation, a position adjustment device is provided in the accommodating cavity of the shielding chamber, and the position adjustment device is used to adjust and locate the position of the target object.

[0036] In a third aspect, the present application provides a radiation protection shielding method, which uses any of the above-mentioned radiation protection shielding devices to perform radiation shielding within a preset area, the method comprising:

[0037] placing the target object in the receiving cavity of the radiation protection shielding device;

[0038] The position of the shielding cabin is adjusted by using the moving device so that the center point of the first window is aligned with the isocenter of the beam, and the second window is completely blocked by the wall in the preset area.

[0039] The beneficial effect of this technical solution is that the target object (for example, a test animal or a Faraday cup) is placed in the second window of the radiation protection shielding device. By adjusting the position of the shielding chamber, the center point of the first window of the radiation protection shielding device is accurately aligned with the isocenter of the beam, which can ensure that the beam is accurately delivered to the target object, and the second window is completely blocked to prevent radiation from leaking outside the preset area, thereby ensuring the safety of the treatment or test process.

[0040] In a possible implementation, the method further includes:

[0041] According to the dose corresponding to the beam, the preset thicknesses of the proton shielding layer and the neutron shielding layer are respectively obtained;

[0042] According to the preset thickness of the proton shielding layer, setting the number of proton shielding units and the thickness of each proton shielding unit;

[0043] The number of neutron shielding units and the thickness of each neutron shielding unit are set according to the preset thickness of the neutron shielding layer.

[0044] The beneficial effects of this technical solution are: accurately setting the thickness of the shielding units of the proton shielding layer and the neutron shielding layer according to the beam dose can maximize the shielding effect. At the same time, accurately setting the number and thickness of the shielding units can maximize the use of resources, avoid excessive consumption of materials, and reduce production costs.

[0045] In a fourth aspect, the present application also provides a FLASH treatment system, which includes: a proton accelerator and any one of the above-mentioned radiation protection shielding devices, wherein the proton accelerator is used to output a beam.

[0046] In a fifth aspect, the present application also provides a computer-readable storage medium, which stores a computer program, and when the computer program is executed by one or more processors, it implements the steps of any of the above methods.

[0047] In a sixth aspect, the present application further provides a computer program product, which includes a computer program, and when the computer program is executed by one or more processors, it implements the steps of any of the above methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The present application is further described below with reference to the accompanying drawings and implementation methods.

[0049] FIG1 is a structural block diagram of a FLASH treatment system provided in an embodiment of the present application.

[0050] FIG2 is a schematic structural diagram of a radiation protection shielding device provided in an embodiment of the present application.

[0051] FIG3 is a schematic structural diagram of a shielding chamber provided in an embodiment of the present application.

[0052] FIG4 is a schematic structural diagram of another shielding chamber provided in an embodiment of the present application.

[0053] FIG5 is a schematic structural diagram of a position adjustment device provided in an embodiment of the present application.

[0054] FIG6 is a schematic structural diagram of a mobile device provided in an embodiment of the present application.

[0055] FIG7 is a schematic structural diagram of another mobile device provided in an embodiment of the present application.

[0056] FIG8 is a schematic structural diagram of two computer rooms provided in an embodiment of the present application.

[0057] FIG9 is a schematic diagram of a radiation shielding simulation result of a computer room 1 provided in an embodiment of the present application.

[0058] FIG10 is a schematic diagram of a radiation shielding simulation result of a computer room 2 provided in an embodiment of the present application.

[0059] FIG11 is a flow chart of a radiation protection shielding method provided in an embodiment of the present application.

[0060] In the figure: 10. Shielding chamber; 11. Proton shielding layer; 12. Neutron shielding layer; 13. First window; 14. Second window; 15. Position adjustment device; 20. Moving device; 21. Workbench; 211. First screw seat; 212. Second screw seat; 22. Hydraulic cylinder; 23. Hydraulic unit; 24. Travel switch; 25. Hydraulic handle; 26. Handwheel; 27. Guide rail; 28. Slider. DETAILED DESCRIPTION

[0061] The following will describe the technical solutions in the embodiments of the present application in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Those skilled in the art will appreciate that with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0062] It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0063] In this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "exemplary" or "for example" should not be construed as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0064] The first, second, etc. descriptions appearing in the embodiments of this application are only for illustration and distinction of the description objects. There is no order, nor does it indicate any special limitation on the number of devices in the embodiments of this application, and cannot constitute any limitation on the embodiments of this application.

[0065] In this application, "at least one" means one or more, and "more" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, a and b, a and c, b and c or a and b and c, where a, b and c can be single or multiple. It is worth noting that "at least one" can also be interpreted as "one or more items".

[0066] Proton tumor therapy is currently one of the most advanced, mature, and high-end medical technologies in the world and a primary method of treating tumors. Compared to the widely used high-energy neutrons and electrons, protons can more effectively focus radiation energy on the target tumor area, improving local tumor control while significantly reducing radiation complications in normal organs and tissues. Proton therapy devices have become the mainstream equipment for tumor radiotherapy internationally.

[0067] FLASH therapy primarily involves delivering a dose to the entire treatment volume in less than a second. Early preclinical evidence suggests that these extremely high dose rates significantly protect healthy tissue without reducing damage to cancer cells compared to conventional radiotherapy. Because FLASH's large beam delivers a very high dose in a very short period of time, it places high demands on radiation shielding walls. In other words, the facility where FLASH radiotherapy is performed must have sufficient radiation shielding capabilities. This requires sufficiently thick radiation shielding walls, which occupy a large area and require significant capital investment.

[0068] Taking the proton therapy system commissioning room as an example, according to the radiation protection standards, the external dose rate control level of the shielding body is shown in Table 1:

[0069] Table 1

[0070] The occupancy factor refers to the average time that the most exposed person resides within the area during the radiation source's beam duration. The dose rate, typically measured in millisieverts or microsieverts, is the amount of radiation energy ingested per unit time. It is an important safety indicator used to assess the impact of radiation on human health.

[0071] If FLASH radiation protection shielding equipment is not installed, very thick radiation shielding walls will be required, which will require a larger area, which will inevitably cost huge amounts of money, ranging from several million to tens of millions.

[0072] Based on this, the embodiments of the present application provide a FLASH treatment system, a radiation protection shielding method and related devices, and design a radiation protection shielding device, namely a FLASH shielding tooling, to meet the radiation protection shielding problem of the machine room during large beam debugging and experiments, and at the same time meet the up and down and front and back adjustment function of this tooling when doing FLASH tests, so that the test target can be debugged to the isocenter position of the equipment, and under the premise of meeting the isocenter position debugging and large beam radiation shielding requirements, the economic cost of a huge shielding wall when doing large beam FLASH tests is saved.

[0073] FLASH therapy system embodiment.

[0074] Referring to FIG1 , FIG1 shows a structural block diagram of a FLASH treatment system provided in an embodiment of the present application.

[0075] An embodiment of the present application further provides a FLASH treatment system, which includes: a proton accelerator and a radiation protection shielding device, wherein the proton accelerator is used to output a beam.

[0076] The embodiments of the present application do not limit the proton accelerator, and the proton accelerator may be an equipotential cyclotron accelerator or a synchrocyclotron accelerator.

[0077] Traditional cyclotrons include equipotential cyclotrons and (pulsed) synchrocyclotrons. While equipotential cyclotrons have a quasi-continuous beam (non-pulsed structure), synchrocyclotrons have a pulsed beam (pulsed structure), a unique characteristic inherent in synchrocyclotron systems. The instantaneous and average dose rates of synchrocyclotron pulsed output offer unique advantages and benefits for FLASH radiation in proton therapy.

[0078] Specifically, the cyclotron consists of five major subsystems, including the ion source subsystem, radio frequency (RF) subsystem, vacuum subsystem, magnet subsystem, and extraction subsystem. Through the complex interactions between the five subsystems, a proton beam for clinical treatment or research is generated. From the appearance, the cyclotron usually looks like a cylinder with two semicircular cylindrical electric boxes separated by a small distance in the middle. The RF subsystem forms an alternating electric field through this separation distance to accelerate the protons as they pass through. As the dipole divides the cylinder into two separate parts, one electrode is shaped like the letter "D" and the other electrode is shaped like an inverted letter "D", which is why the dipole is commonly known as a "D-shaped electrode". There is a magnetic field in the D-shaped electrode that guides particles (i.e., protons) from one D-shaped electrode to the other D-shaped electrode, and the protons also gain energy when passing through this slit.

[0079] The protons turn and follow a tortuous path back to the slit and the opposing D-electrode. They pass through the slit, accelerate, then enter the opposing D-electrode, returning along a tortuous path to the slit and the opposing D-electrode. This process repeats until the protons reach an extraction point near the outer edge of one of the D-electrodes. At this point, the extraction subsystem directs the proton beam into downstream subsystems for further modification until it ultimately enters the target area within the patient or subject. Because the protons are accelerated as they pass through the slit, their entire path follows an outward-extending spiral.

[0080] In one implementation, the proton accelerator is a pulsed synchronous cyclotron accelerator.

[0081] Pulsed synchrocyclotrons deliver protons at ultra-high dose rates, accelerating them to 230 MeV (in the range of 32.0 g / cm², used for potential FLASH radiotherapy experiments, with a 1.3 ms inter-pulse time and an ion source pulse duration of approximately 21 μs). This corresponds to an average dose rate of approximately 100 Gy / s and an instantaneous dose rate of approximately 6200 Gy / s at the Bragg peak during pulses at a FLASH dose rate repetition rate of 750 Hz. While such high instantaneous dose rates offer significant advantages for FLASH therapy and research, they also place significant demands on the radiation shielding equipment within the FLASH therapy system. Therefore, the design of radiation protection shielding methods and related devices for FLASH therapy systems is crucial and essential.

[0082] In one implementation, the FLASH treatment system further includes a first ionization chamber, a carbide absorber, a collimator, and a second ionization chamber sequentially arranged at intervals along the beam direction;

[0083] The carbide absorber is used to adjust the energy range of the proton accelerator according to the tumor information of the target object, wherein the target object is an animal or a human with a tumor;

[0084] The collimator is used to calibrate the beam;

[0085] The first ionization chamber is used to measure the real-time dose of the beam and feed the real-time dose back to the dose control system;

[0086] The second ionization chamber is used to measure the absolute dose of the beam and is located before the first window.

[0087] In one implementation, the FLASH therapy system further includes a Faraday cup near the second window, wherein the Faraday cup is used to measure the size of the beam and collect excess beam.

[0088] The first ionization chamber, the real-time dose ionization chamber, monitors and tests the beam dose online and provides rapid feedback to the dose control system. A carbide absorber adjusts the energy range of the proton accelerator based on the tumor profile of the target patient. A collimator eliminates excess beam radiation, sharpening the beam edge. The second ionization chamber, the absolute dose ionization chamber, measures the absolute dose of the beam. A Faraday cup measures beam size and collects and blocks excess beam radiation.

[0089] Many studies on the differential effects of high and low doses of proton radiotherapy have shown that higher dose rates (usually exceeding 40 Gy / s) affect normal tissues, and that treatments with total treatment times of less than 1 second show less normal tissue toxicity while maintaining the typical tumor control of traditional treatments. Industry studies have shown that FLASH is a revolutionary discovery in the field of radiotherapy. In the application of proton therapy, it is important to consider these studies in conjunction with the conformation provided by the Bragg peak. Conventional doses are generally between 40 Gy and 100 Gy. In order to evaluate the impact of FLASH dose rate within the diffuse Bragg peak (SOBP), a dosimetry method was designed to measure FLASH and conventional dose rates.

[0090] The present invention uses active and passive dosimetry techniques to achieve redundancy and effective beam steering. A large body of literature focuses on the response characteristics of dosimeters to ultra-high dose rate delivery, including discussions of recombination effects and thin film dose rate effects in parallel plate ionization chambers.

[0091] In one implementation, the collimator employs a PPC05 chamber for in vivo recording of the total dose and dose rate at the delivery site.

[0092] Specifically, a plane-parallel ionization chamber PPC05 was used to measure absolute dose at the entrance depth and at the Bragg peak. The bias voltage was set sequentially to 150 V, 300 V, 450 V, and +450 V. Generally, the maximum bias voltage was 500 V. The diameter of the chamber was fabricated on a chamber support model made of polycarbonate. Therefore, the effective point of measurement was 2.3 mm WET. To measure at the Bragg peak, the effective measurement point on the chamber support model was 4.13 cm. The sensitive volume used for measurement in the Bragg peak ionization chamber was longitudinally at the Bragg peak.

[0093] The first ionization chamber and / or the second ionization chamber adopts a transmission ionization chamber TIC (tissue-equivalent ionization chamber).

[0094] Transmission ionization chamber TIC and fixed film measurement As a redundant measurement, the transmission ionization chamber TIC is generally connected to a dose measurement system for real-time dose measurement and dose control.

[0095] The embodiment of the present application uses a synchrotron to generate the beam, which is a single scattering point with an energy of 230 MeV. In order to provide a dose at the Bragg peak, the target object is placed in a boron carbide absorber with a water equivalent thickness (WET) of about 30 cm and a collimator with a diameter of about 2 times the beam spot size. In addition, a small thickness of WET polyethylene absorber is used to adjust the beam delivery depth, allowing the target object and the absorber to be positioned at a configurable distance from the apparent source of radiation and laterally centered. If a larger clinically relevant target volume is treated with a FLASH treatment system, it is necessary to expand the beam laterally and in depth while maintaining the local dose rate. In practical applications, a ridge filter can be used, which is placed upstream of the boron carbide absorber to modify the depth profile of the beam to produce SOBP without the need for active modulation. Specifically, the ridge filter consists of a grid of machined holes passing through an acrylic plastic (PMMA) block.

[0096] The initial average kinetic energy of the protons was set at 230 MeV, with an energy spread of 0.3%. The beam exit spot size was 4-5 mm. The energy spread of the treatment isocenter and beam in air was no more than 1.5 mrad. A length of boron carbide block was placed downstream of the cyclotron and then irradiated using a 1 cm thick brass collimator. The square opening in the collimator was larger than the diameter of the brass collimator and was used to collimate the beam generated by the proton absorber after undergoing large-angle Coulomb scattering.

[0097] In one implementation, the target subject, which can be a small animal (e.g., a mouse), is anesthetized before beam delivery and maintained continuously during the experiment. Real-time image acquisition is used to ensure that the target subject exhibits no noticeable movement during treatment. If the target subject is another type of subject, it is also necessary to ensure that the subject remains motionless during beam delivery.

[0098] A Faraday cup is used to measure the flux or flux in a proton beam. The Faraday cup consists of a shielding insulating block thick enough to block the incident protons. The charge deposited in the Faraday cup is proportional to the number of protons stopped in the block, and thus corresponds to the total flux of incident protons.

[0099] The following is a detailed introduction to radiation protection shielding equipment.

[0100] Refer to Figure 2, which shows a schematic structural diagram of a radiation protection shielding device provided in an embodiment of the present application.

[0101] An embodiment of the present application also provides a radiation protection shielding device, which includes a shielding chamber 10 and a moving device 20. The moving device 20 is used to adjust the position of the shielding chamber 10 so that the center point of the first window 13 is aligned with the isocenter of the beam.

[0102] By using the mobile device 20 to align the center of the first window 13 of the shielding chamber 10 with the isocenter of the beam, it is possible to ensure that the beam is accurately delivered to the tumor area of ​​the target object, thereby improving the accuracy of FLASH radiotherapy. After the large-beam FLASH radiotherapy is completed, the shielding chamber 10 can be moved to other storage locations by the mobile device 20, thereby avoiding the problem of adding radiation shielding walls to the proton accelerator room in order to carry out large-beam FLASH radiotherapy. Under the premise of flexible operation, a huge amount of infrastructure economic costs and floor space costs can be saved. In summary, the present application can meet the radiation protection requirements of large-beam FLASH radiotherapy, and can also meet the function of locating the isocenter, thereby reducing floor space and infrastructure costs.

[0103] The shielding chamber is introduced in detail below.

[0104] 3 and 4 , FIG3 shows a schematic structural diagram of a shielding compartment provided in an embodiment of the present application; FIG4 shows a schematic structural diagram of another shielding compartment provided in an embodiment of the present application.

[0105] The present application provides a shielding chamber 10 for radiation protection, wherein the shielding chamber 10 has a accommodating cavity and a first window 13 and a second window 14 arranged on the shielding chamber and arranged in sequence along the beam direction. The center point of the first window 13 and the center point of the second window 14 are located on the same straight line as the central axis of the beam. The first window 13 and the second window 14 are respectively connected to the accommodating cavity. The first window 13 is used for the beam to enter and is smaller than the second window 14. The second window 14 is used for the target object to pass through and be accommodated in the accommodating cavity. The second window 14 is set to be close to the radiation shielding wall of the treatment room, and the geometric center point of the accommodating cavity is set to the Bragg peak position of the beam.

[0106] The target can be a small animal or a patient undergoing proton radiotherapy. A Faraday cup is a metal, cup-shaped vacuum detector used to measure the intensity of incident charged particles. The measured current can be used to determine the number of incident electrons or ions. For example, the target can be an animal or human with a tumor.

[0107] This application does not limit the size of the shielding chamber 10. The length of the shielding chamber 10 along the beam exit direction can be 1000mm, 1400mm, 1800mm, or 2000mm. The width of the shielding chamber 10 can be 800mm, 1000mm, 1400mm, or 1600mm. The shielding chamber 10 can be raised or lowered in a range of 500mm to 1500mm. The load capacity of the shielding chamber 10 can be 3.2T, 4.3T, 4.6T, or 5T.

[0108] Therefore, traditionally, to meet radiation shielding requirements, FLASH radiotherapy requires the construction of thick radiation shielding walls, resulting in high capital investment and increased floor space. However, the present application provides a mobile device 20 and a shielding chamber 10, allowing the radiation protection shielding equipment to be repositioned according to treatment needs. This eliminates the need for overly thick fixed shielding walls, saving space and costs.

[0109] In some embodiments, the shielding chamber 10 is a stacked structure that is sequentially arranged from the inside out in a spiral installation. The shielding chamber 10 includes a proton shielding layer 11 and a neutron shielding layer 12 that are sequentially arranged from the inside out.

[0110] The shielding chamber 10 adopts a detachable stacked structure, which can be spliced ​​into proton shielding layers 11 and neutron shielding layers 12 of different thicknesses according to the dose, so as to meet the radiation protection requirements in different application scenarios.

[0111] In some embodiments, the proton shielding layer 11 includes M proton shielding units stacked from the inside out, and the neutron shielding layer 12 includes N neutron shielding units stacked from the inside out, where M and N are both positive integers.

[0112] Thus, the proton shielding layer 11 and the neutron shielding layer 12 are composed of multiple stacked shielding units. The number of shielding units can be increased without increasing the overall thickness of the shielding chamber 10. Each layer of shielding units effectively absorbs and reduces radiation penetration, thereby further reducing the radiation level in the external environment. Each layer of shielding units is independently removable, and the number of shielding units can be flexibly selected, increased, or decreased according to specific circumstances to meet the radiation shielding requirements of different application scenarios, thereby adapting the radiation protection shielding device to different treatment doses and radiation sources.

[0113] In some embodiments, the material of the proton shielding unit includes one or more of the following: stainless steel, lead, aluminum, and concrete; the material of the neutron shielding unit includes one or more of the following: polyethylene, polypropylene, polystyrene, polyester, boron, lead, tungsten, iron, and barium.

[0114] Therefore, the proton shielding unit can be made of stainless steel, lead, aluminum, concrete and other materials, and the neutron shielding unit can be made of polyethylene, polypropylene, polystyrene, polyester, boron, lead, tungsten, iron, barium and other materials. These materials are low-cost and easy to obtain, and can reduce the manufacturing cost and maintenance cost of radiation protection shielding equipment while meeting the radiation shielding requirements.

[0115] In some embodiments, M=N=5.

[0116] Therefore, the number of layers of shielding units of the proton shielding layer 11 and the neutron shielding layer 12 can be the same. Setting 5 layers of shielding units can reduce the volume and weight of the entire shielding chamber 10 while meeting the radiation shielding requirements. On the one hand, it is convenient for disassembly, and on the other hand, it is convenient for the mobile device 20 to adjust the position of the shielding chamber 10.

[0117] In some embodiments, the cross-sectional shape of the shielding chamber 10 along the direction perpendicular to the beam emission direction may be rectangular, for example, square.

[0118] The proton shielding layer 11 and the neutron shielding layer 12 are respectively formed by splicing five shielding units (plates). The plane away from the beam emission direction is not spliced ​​with plates, naturally forming a larger window (i.e., the second window 14). A smaller window, i.e., the first window 13, is opened on the plane facing the beam emission direction.

[0119] In one implementation, the inner proton shielding layer 11 is formed by stacking five layers of stainless steel plates.

[0120] The outer neutron shielding layer 12 is formed by stacking 5 layers of polyethylene sheets (PE sheets).

[0121] In one implementation, the shielding chamber 10 is composed of a stainless steel plate and a PE plate. The stainless steel layer can shield the protons generated by the flash, and the PE can shield the neutrons generated by the flash.

[0122] The embodiment of the present application does not limit the size and shape of the first window 13 and the second window 14. The shapes of the first window 13 and the second window 14 can be the same or different, for example, they can be rectangular, circular, regular polygonal, triangular, fan-shaped or irregular.

[0123] Generally speaking, the first window 13 needs to be aligned with the beam outlet, mainly to allow the beam to enter through the first window 13 and sufficiently cover the scattered beam during flight. The second window 14 needs to be aligned with the wall. The size of the second window 14 can be flexibly set according to the size of the target object.

[0124] The first window 13 and the second window 14 can both be square in shape, wherein the side length of the first window 13 can be 50 mm, 80 mm, 100 mm or 150 mm, and the side length of the second window 14 can be 300 mm, 500 mm, 700 mm or 800 mm.

[0125] Referring to FIG. 5 , FIG. 5 shows a schematic structural diagram of a position adjustment device provided in an embodiment of the present application.

[0126] In one implementation, a position adjustment device 15 is provided in the accommodating cavity of the radiation protection shielding device, and the position adjustment device 15 is used to adjust and locate the position of the target object.

[0127] The position adjustment device 15 can be used as a treatment bed for the target object. The position adjustment device 15 is provided with a first guide rail that can drive the target object to move forward and backward, and a second guide rail that can drive the target object to move left and right.

[0128] By providing the position adjustment device 15 , the position of the target object can be adjusted and positioned, thereby ensuring that the beam can be accurately delivered to the tumor area of ​​the target object.

[0129] In some embodiments, a positioning mark is provided at the center of the first window 13 , and the positioning mark is used to indicate the center point of the first window 13 . The first window 13 and the second window 14 are located on opposite sides of the shielding chamber 10 .

[0130] In one implementation, the positioning mark can be a crosshair. The ISO (isocenter) position of the device is located by using an external laser light to crosshair. A crosshair is engraved on the first window 13 (polyethylene front panel). The crosshair of the external laser light is aligned with the crosshair by adjusting the hydraulic handle 25 up and down. The accuracy can reach ±1mm, meeting the ISO positioning requirements.

[0131] Therefore, by setting the positioning mark, the operator can accurately determine the position of the center point of the first window 13 and ensure that it is aligned with the isocenter of the beam, which helps to ensure that the beam is accurately delivered to the target object and improve the accuracy of the test or treatment.

[0132] 6 and 7 , FIG6 shows a schematic structural diagram of a mobile device provided in an embodiment of the present application; FIG7 shows a schematic structural diagram of another mobile device provided in an embodiment of the present application.

[0133] In some embodiments, the mobile device 20 includes:

[0134] A workbench 21 is used to carry the shielding chamber 10 and drive the shielding chamber 10 to move up and down;

[0135] The driving module is used to provide lifting power for the workbench 21.

[0136] Thus, by using the workbench 21 in conjunction with the drive module, the position of the shielding chamber 10 can be flexibly adjusted. Compared to traditional fixed radiation shielding walls, the use of the mobile device 20 can save space. The lifting and lowering movement of the workbench 21 can adjust the position of the shielding chamber 10 without requiring excessive floor space.

[0137] In some embodiments, the moving device 20 is a hydraulic scissor lift, the driving module includes a hydraulic cylinder 22 and a hydraulic unit 23 , and the moving device 20 also includes a travel switch 24 and a hydraulic handle 25 .

[0138] In one implementation, the weight of the mobile device 20 may be 1.5T, 1.8T, or 2T.

[0139] The hydraulic cylinder 22 may be of model 63-35*150. The hydraulic unit 23 (also known as a hydraulic power unit or hydraulic station) is connected to the hydraulic cylinder 22 via an external piping system to control the movement of multiple valves. The hydraulic unit 23 may have a power of 3KW, a displacement of 10CC, and a pressure of 12Mpa.

[0140] Thus, the hydraulic scissor lift provides a stable lifting motion, ensuring that the shielding chamber 10 remains stable during the adjustment process, avoiding unnecessary vibration and shaking. Specifically, the drive module uses a hydraulic cylinder 22 and a hydraulic unit 23 to precisely control the speed and position of the lifting motion, making the lifting and adjustment of the shielding chamber 10 more accurate and controllable. By providing a limit switch 24 and a hydraulic handle 25, the operator can control the lifting motion through the limit switch 24 and the hydraulic handle 25, making the adjustment process more convenient and efficient.

[0141] In some embodiments, the moving device 20 further includes a planar moving component disposed on the upper surface of the workbench 21 , and the planar moving component is used to change the position of the shielding chamber 10 on the workbench 21 .

[0142] The planar moving component is a ball screw module. The first window 13 and the second window 14 are located on opposite sides of the shielding chamber 10. The workbench 21 is connected to the shielding chamber 10 through the ball screw module so that the shielding chamber 10 moves back and forth along the beam movement direction.

[0143] Therefore, by providing a ball screw module, the shielding chamber 10 can be moved back and forth along the beam movement direction. The ball screw module can provide precise linear motion, ensuring that the position adjustment of the shielding chamber 10 is more accurate.

[0144] In some embodiments, the ball screw module is provided with a hand wheel 26 and a screw.

[0145] The bottom of the shielding chamber 10 is slidably set on the guide rail 27 on the upper surface of the workbench 21. Two first screw rod seats 211 are set on the upper surface of the workbench 21. A second screw rod seat 212 is set at the bottom of the shielding chamber 10. One end of the screw rod is connected to the handwheel 26, and the other end of the screw rod passes through the screw holes on one of the first screw rod seat 211 and the second screw rod seat 212 in sequence and is connected to the other first screw rod seat 211.

[0146] Thus, the handwheel 26, as a control device, provides an intuitive operation method. The operator can rotate the handwheel 26 to control the movement of the shielding chamber 10, and the operation is simple and clear. Specifically, by controlling the ball screw module through the handwheel 26, the forward and backward movement distance of the shielding chamber 10 can be controlled according to the rotation angle. This precise control method allows the operator to accurately adjust the position of the shielding chamber 10. Moreover, the control method of the handwheel 26 enables a quick response during the adjustment process, meeting the immediate needs of treatment or testing.

[0147] In one implementation, the mobile device 20 is further provided with a slider 28 and a guide rail 27. The slider 28 is provided on the lower surface of the shielding chamber 10, and the guide rail 27 is provided on the upper surface of the working platform. The guide rail 27 is provided parallel to the travel direction of the ball screw module, and the shielding chamber 10 is driven to perform forward and backward linear motion by the clockwise and counterclockwise rotation of the handwheel 26.

[0148] Refer to Figure 8, which shows a schematic structural diagram of two computer rooms provided in an embodiment of the present application.

[0149] In a specific application scenario, a FLASH test was conducted on the proton debugging room to verify the radiation shielding conditions with and without the radiation protection shielding equipment. The results are shown in Figures 9 and 10.

[0150] FIG9 shows a schematic diagram of a radiation shielding simulation result of a computer room 1 provided in an embodiment of the present application.

[0151] FIG10 shows a schematic diagram of a radiation shielding simulation result of a computer room 2 provided in an embodiment of the present application.

[0152] It can be seen that the dose difference inside the debugging room with radiation protection shielding equipment (room 1) and without radiation protection shielding equipment (room 2) is roughly three orders of magnitude. If the debugging room is not equipped with radiation protection shielding equipment, the wall of the room will have to be about twice as thick as the actual thickness. In this way, the building size of the entire room will inevitably increase a lot, and the radiation monitoring of radiation protection will also require a more detailed design.

[0153] The following is a detailed introduction to a radiation protection shielding method.

[0154] Referring to FIG. 11 , FIG. 11 shows a schematic flow chart of a radiation protection shielding method provided in an embodiment of the present application.

[0155] The present application also provides a radiation protection shielding method, which uses any of the above-mentioned radiation protection shielding devices to perform radiation shielding within a preset area, the method comprising:

[0156] S1: placing the target object in the receiving cavity of the radiation protection shielding device;

[0157] S2: Using the moving device 20 to adjust the position of the shielding chamber 10, so that the center point of the first window 13 is aligned with the isocenter of the beam, and the second window 14 is completely blocked by the wall in the preset area.

[0158] Furthermore, the target object (for example, a test animal or a Faraday cup) is placed in the accommodating cavity of the radiation protection shielding device. By adjusting the position of the shielding chamber 10, the center point of the first window 13 of the radiation protection shielding device is accurately aligned with the isocenter of the beam, thereby ensuring that the beam is accurately delivered to the target object, and completely blocking the second window 14 to prevent radiation from leaking outside the preset area, thereby ensuring the safety of the treatment or test process.

[0159] In some embodiments, the method further comprises:

[0160] According to the dose corresponding to the beam, respectively obtain the preset thicknesses of the proton shielding layer 11 and the neutron shielding layer 12;

[0161] According to the preset thickness of the proton shielding layer 11, the number of proton shielding units and the thickness of each proton shielding unit are set;

[0162] The number of neutron shielding units and the thickness of each neutron shielding unit are set according to the preset thickness of the neutron shielding layer 12 .

[0163] Furthermore, accurately setting the thickness of the shielding units of the proton shielding layer 11 and the neutron shielding layer 12 according to the beam dose can maximize the shielding effect. At the same time, accurately setting the number and thickness of the shielding units can maximize the use of resources, avoid excessive consumption of materials, and reduce production costs.

[0164] The embodiment of the present application also provides a computer-readable storage medium, the specific embodiment of which is consistent with the embodiment described in the above method embodiment and the technical effects achieved, and some contents will not be repeated here.

[0165] The computer-readable storage medium stores a computer program, and when the computer program is executed by one or more processors, the steps of any of the above methods are implemented.

[0166] The present application embodiment provides a program product, which is used to implement the steps of any of the above methods. The program product can use a portable compact disc read-only memory (CD-ROM) and include program code, and can be run on a terminal device, such as a personal computer. However, the program product is not limited to this. In one implementation, the readable storage medium can be any tangible medium that contains or stores a program, which can be used by an instruction execution system, device or device or used in combination with it. The program product can use any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of readable storage media (non-exhaustive list) include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0167] A computer-readable storage medium may include a data signal propagated in baseband or as part of a carrier wave, which carries readable program code. This propagated data signal may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the foregoing. The readable storage medium may also be any readable medium that can send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device. The program code contained on the readable storage medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical cable, RF, or any suitable combination of the foregoing. The program code for performing the operations of this application may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C++, and conventional procedural programming languages ​​such as C or similar programming languages. The program code may be executed entirely on the user computing device, partially on the terminal device, as a standalone software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. Where a remote computing device is involved, the remote computing device may be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., through the Internet using an Internet service provider).

Claims

1. A shielding chamber for radiation protection, the shielding chamber comprising a containing chamber and a first window and a second window arranged on the shielding chamber and arranged in sequence along a beam direction, the center point of the first window and the center point of the second window being located on the same straight line as the center axis of the beam, the first window and the second window being connected to the containing chamber respectively, the first window being used for the beam to enter and being smaller than the second window, the second window being used for a target object to pass through and be contained in the containing chamber, the second window being arranged to be close to a radiation shielding wall of a treatment room, and the geometric center point of the containing chamber being arranged to be a Bragg peak position of the beam; The shielding chamber is a stacked structure that is sequentially arranged from the inside to the outside and is spirally installed, and the shielding chamber includes a proton shielding layer and a neutron shielding layer that are sequentially arranged from the inside to the outside; A positioning mark is arranged at the center of the first window, and the positioning mark is used to indicate the center point of the first window. The first window and the second window are located at opposite sides of the shielding chamber.

2. The shielding chamber for radiation protection according to claim 1, wherein: The proton shielding layer includes M proton shielding units stacked from the inside to the outside, and the neutron shielding layer includes N neutron shielding units stacked from the inside to the outside, where M and N are both positive integers, wherein M=N.

3. The shielding chamber for radiation protection according to claim 2, wherein: The materials of the proton shielding unit include one or more of the following: stainless steel, lead, aluminum and concrete; the materials of the neutron shielding unit include one or more of the following: polyethylene, polypropylene, polystyrene, polyester, boron, lead, tungsten, iron and barium.

4. A radiation protection shielding device comprising: A shielding chamber for radiation protection as described in any one of claims 1 to 3; The moving device is used to adjust the position of the shielding chamber so that the center point of the first window is aligned with the isocenter of the beam.

5. The radiation protection shielding device according to claim 4, wherein: The mobile device comprises: A workbench, used for carrying the shielding bin and driving the shielding bin to perform lifting motion; The driving module is used to provide lifting power for the workbench.

6. The radiation protection shielding device according to claim 5, wherein: The moving device adopts a hydraulic scissor lift, the driving module includes a hydraulic cylinder and a hydraulic unit, and the moving device also includes a travel switch and a hydraulic handle.

7. The radiation protection shielding device according to claim 5, wherein: The moving device further comprises a planar moving component disposed on the upper surface of the workbench, and the planar moving component is used to change the position of the shielding chamber on the workbench.

8. The radiation protection shielding device according to claim 7, wherein: The planar moving component is a ball screw module, the first window and the second window are located on opposite sides of the shielding chamber, and the workbench is connected to the shielding chamber through the ball screw module so that the shielding chamber moves back and forth along the beam movement direction.

9. The radiation protection shielding device according to claim 8, wherein: The ball screw module is provided with a hand wheel and a screw rod; The bottom of the shielding bin is slidably arranged on the guide rail on the upper surface of the workbench, two first screw seats are arranged on the upper surface of the workbench, and a second screw seat is arranged at the bottom of the shielding bin. One end of the screw is connected to the handwheel, and the other end of the screw passes through the screw holes on one of the first screw seat and the second screw seat in sequence and is connected to the other first screw seat.

10. The radiation protection shielding device according to claim 4, wherein: A position adjustment device is arranged in the accommodating cavity of the shielding chamber, and the position adjustment device is used to adjust and locate the position of the target object.

11. A FLASH treatment system, comprising: A proton accelerator and the radiation protection shielding device according to any one of claims 4 to 10, wherein the proton accelerator is used to output a beam.

12. The FLASH treatment system according to claim 11, wherein: The FLASH treatment system also includes a first ionization chamber, a carbide absorber, a collimator, and a second ionization chamber which are sequentially arranged at intervals along the beam direction; Wherein, the carbide absorber is used to adjust the energy range of the proton accelerator according to the tumor information of the target object, wherein the target object is an animal or a human being with a tumor; The collimator is used to calibrate the beam; The first ionization chamber is used to measure the real-time dose of the beam and feed the real-time dose back to the dose control system; The second ionization chamber is used to measure the absolute dose of the beam and is located before the first window.

13. The FLASH treatment system according to claim 12, wherein: The FLASH treatment system further includes a Faraday cup close to the second window, and the Faraday cup is used to measure the size of the beam and collect excess beam.

14. A radiation protection shielding method, the radiation protection shielding method using the radiation protection shielding device according to any one of claims 4 to 10 to perform radiation shielding in a preset area, the method comprising: Placing the target object in the receiving chamber of the radiation protection shielding device; The position of the shielding chamber is adjusted by using the moving device so that the center point of the first window is aligned with the isocenter of the beam, and the second window is completely shielded by the wall in the preset area.

15. The radiation protection shielding method according to claim 14, wherein: The radiation protection shielding method also includes: According to the dose corresponding to the beam, respectively obtain the preset thickness of the proton shielding layer and the neutron shielding layer; According to the preset thickness of the proton shielding layer, the number of proton shielding units and the thickness of each proton shielding unit are set; The number of neutron shielding units and the thickness of each neutron shielding unit are set according to the preset thickness of the neutron shielding layer.

16. A computer-readable storage medium storing a computer program, wherein the computer program implements the steps of the method according to any one of claims 14 to 15 when executed by one or more processors.

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