Range shifter, control method and radiotherapy device

Abstract

A range shifter (100), a control method and a radiotherapy device. The range shifter (100) comprises a plurality of range adjustment plates (1) and a motion control mechanism (2), wherein the range adjustment plates (1) are configured to perform range adjustment on a particle beam by using different combinations when allowing a particle beam flow to pass through; and the motion control mechanism (2) comprises a plurality of driving apparatuses (20) and a motion controller (25) used for controlling the driving apparatuses (20), the driving apparatuses (20) being configured to move the range adjustment plates (1) into or out of an advancing path of the particle beam flow, so as to adjust the total thickness of the range adjustment plates (1) which the particle beam flow passes through, thereby realizing range adjustment of the particle beam. The range adjustment plates (1) have a small scattering effect on the particle beam flow, so that a change in a beam spot is small after the particle beam passes through the adjustment plates, thereby ensuring that the particle beam flow accurately reaches an affected part with a relatively small beam spot; and the range adjustment plates (1) can expand the scope of range adjustment of the particle beam flow, thereby facilitating an improvement in treatment efficiency and an improvement in a treatment effect.

Description

Range shifter, control method, and radiotherapy device

[0001] This application claims priority to Chinese Patent Application No. CN202310958360.1 filed on August 1, 2023, which is incorporated by reference in its entirety. Technical Field

[0002] The present application relates to the technical field of high-end medical equipment, for example, to a range shifter, a control method and radiotherapy equipment. Background Art

[0003] Cancer has become one of the greatest threats to human health. Traditional treatments include surgery, chemotherapy, and X-ray radiotherapy, all of which have significant side effects. Currently, more advanced particle radiotherapy equipment is used to treat cancer. These devices use range shifters to control the particle beam for precise treatment of the affected area. Range shifters can vary the energy of the particle beam to target tumors at varying depths within the human body. However, current range shifters can cause significant scattering of the particle beam, which in turn increases the size of the beam spot. This results in less than ideal dose conformity in the target area during particle beam therapy, thus impacting treatment effectiveness.

[0004] Furthermore, the related range shifter needs to be further improved.

[0005] Summary of the Invention

[0006] The purpose of the present application is to provide a range shifter, a control method and a radiotherapy device, wherein the range adjustment plate has a small scattering effect on the particle beam, thereby keeping the beam spot of the particle beam unchanged after passing through the adjustment plate, thereby ensuring that the particle beam reaches the affected area more accurately and stably with a smaller beam spot. Multiple range adjustment plates can expand the adjustment range of the particle beam range.

[0007] The purpose of this application is achieved by the following technical solutions:

[0008] The present application provides a range shifter, comprising:

[0009] a plurality of range adjustment plates, the plurality of range adjustment plates being arranged parallel to each other, the range adjustment plates being used for allowing the particle beam to pass through, the material of the range adjustment plates being boron-containing polyethylene or boron-containing polypropylene;

[0010] A motion control mechanism includes a plurality of drive devices and a motion controller, wherein the motion controller is used to control the drive devices, and the drive devices are used to drive the range adjustment plate, and the drive devices are used to move the range adjustment plate into or out of the travel path of the particle beam to adjust the total thickness of the range adjustment plate through which the particle beam passes.

[0011] In one possible implementation, the density of the boron-containing polyethylene is 1.95 to 2.15 g / cm 3 The density of the boron-containing polypropylene is 1.93 to 2.13 g / cm 3 .

[0012] In a possible implementation, the thicknesses of the plurality of range adjustment plates are all the same, or at least some of the range adjustment plates have different thicknesses. The particle beam is a proton beam. Along the direction of the proton beam, the thickness of the last range adjustment plate passed by the proton beam is the largest. The thicknesses of the range adjustment plates are set based on the Bragg peak width (80%-80%) in water at the nominal energy of the proton beam as a reference X. The equivalent water thicknesses of the plurality of range adjustment plates are in a multiple relationship along the direction of the proton beam, and the multiple relationships are 1 / 4X, 1 / 2X, 1X, 2X, 4X, and 8X, respectively.

[0013] In a possible implementation, it also includes a support base, which is U-shaped, and multiple driving devices are respectively arranged at the first end and the second end of the support base, each of the driving devices includes a driving motor, an actuating bearing and a brake, the third end of the actuating bearing is arranged on the support base, the driving motor is arranged at the fourth end of the actuating bearing, and the brake is connected to the range adjustment plate and is sleeved on the actuating bearing.

[0014] In a possible implementation, the motion control mechanism further includes a first position sensor, which is connected to the drive motor and the motion controller, and is used to detect the rotational motion of the drive motor to obtain position information of the range adjustment plate.

[0015] In one possible implementation, the motion control mechanism further includes a second position sensor, a plurality of which are arranged in the motion direction of the brake, the second position sensor being connected to the motion controller, and the second position sensor being used to detect the position of the brake to obtain position information of the range adjustment plate.

[0016] In a possible implementation, it further includes a plurality of slide rails and adjustment brackets, wherein the slide rails are arranged in one-to-one correspondence with the actuating bearings, the range adjustment plate is arranged on the adjustment bracket, the fifth end of the adjustment bracket is connected to the brake, and the sixth end of the adjustment bracket is connected to the slide rail.

[0017] In a possible implementation, a third position sensor is provided on the slide rail, the third position sensor is connected to the motion controller, and the third position sensor is used to obtain position information of the range adjustment plate.

[0018] In a possible implementation, a limiting device is further included, wherein the limiting device is disposed above the range adjustment plate and is used to limit the range of movement of the range adjustment plate; or

[0019] There are gaps between adjacent range adjustment plates so that the movements of the range adjustment plates will not interfere with or affect each other.

[0020] The present application also provides a method for controlling a range shifter, using any of the above-described range shifters, comprising the following steps:

[0021] The motion controller determines the required total thickness of the range adjustment plate according to parameter information set by the system;

[0022] The motion controller controls the driving device to move the required range adjustment plate into the travel path of the particle beam;

[0023] The motion controller determines again the required total thickness of the range adjustment plate according to the change of the system parameter information;

[0024] The motion controller controls the driving device to move the required range adjustment plate into or out of the traveling path of the particle beam.

[0025] In one possible implementation, the motion controller controls the driving device to move the range adjustment plate that is not currently needed to the beam spot edge position or a position outside the beam spot edge of the particle beam's travel path according to the position of the particle beam, so as to reduce the switching distance of the range adjustment plate combination.

[0026] The present application also provides a radiotherapy device, comprising a treatment gantry, a proton accelerator, a scanning magnet, an ionization chamber, and a range shifter as described above. The radiotherapy device is configured to have no beam transmission line, and the proton accelerator is mounted on the treatment gantry and can rotate with the treatment gantry.

[0027] The range shifter, control method, and radiotherapy device of the present application have at least the following advantages:

[0028] The range shifter, control method and radiotherapy equipment of the present application use a range adjustment plate made of boron-containing polyethylene or boron-containing polypropylene. The range adjustment plate can reduce the scattering of the particle beam and keep the beam spot of the particle beam as small as possible, thereby ensuring that the particle beam reaches the affected area stably and accurately with a smaller beam spot. The range adjustment plate is moved in or out of the travel path of the particle beam through a motion control mechanism, which can expand the adjustment range of the particle beam range. The range shifter of the present application is small in size and compact in structure, and can quickly realize energy adjustment of the particle beam, which helps to improve treatment efficiency and treatment effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG1 is a schematic structural diagram of a range shifter according to an embodiment of the present application.

[0030] FIG2 is an exploded schematic diagram of the range adjustment plate and the adjustment bracket according to an embodiment of the present application.

[0031] FIG3 is a comparison diagram of the total thickness of the range adjustment plates required when the particle beam according to an embodiment of the present application passes through the range adjustment plates made of different materials for energy reduction.

[0032] FIG4 is a comparison diagram of the beam spot sizes formed when the particle beam according to an embodiment of the present application passes through range adjustment plates made of different materials.

[0033] FIG5 is a flow chart of a method for controlling a range shifter according to an embodiment of the present application.

[0034] In the figure: 100, range shifter; 1, range adjustment plate; 2, motion control mechanism; 20, driving device; 201, driving motor; 202, actuator bearing; 2021, third end; 2022, fourth end; 203, brake; 2031, sensing part; 21, first position sensor; 22, second position sensor; 23, third position sensor; 25, motion controller; 3, supporting base; 30, first end; 31, second end; 4, slide rail; 5, adjustment bracket; 50, hollow part; 51, clamping structure; 52, fifth end; 53, sixth end; 6, limit device. DETAILED DESCRIPTION

[0035] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this application will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. Identical reference numerals in the figures represent identical or similar structures, and thus repeated descriptions thereof will be omitted.

[0036] The words expressing position and direction described in this application are all explained based on the accompanying drawings as examples, but can be changed as needed, and all changes are included in the scope of protection of this application.

[0037] Referring to Figures 1 and 2, Figure 1 is a schematic diagram of the structure of the range shifter of an embodiment of the present application, Figure 2 is a schematic diagram of the decomposition of the range adjustment plate and the adjustment bracket of an embodiment of the present application, Figure 3 is a comparison diagram of the total thickness of the range adjustment plate required when the particle beam of the embodiment of the present application passes through the range adjustment plate of different materials to reduce the energy, Figure 4 is a comparison diagram of the beam spot size formed when the particle beam of the embodiment of the present application passes through the range adjustment plate of different materials, and Figure 5 is a flow chart of the control method of the range shifter of the embodiment of the present application. The present application provides a range shifter 100, comprising: a plurality of range adjustment plates 1 and a motion control mechanism 2, the motion control mechanism 2 being used to adjust the position of the range adjustment plate 1.

[0038] The shape of the range adjustment plate 1 can be, for example, a quadrilateral, a triangle, a circle, or other polygons. In some possible embodiments, the shape of the range adjustment plate 1 is a rectangle. The range adjustment plate 1 is used to allow a particle beam (not shown) to pass through. The surfaces of the multiple range adjustment plates 1 are arranged perpendicular to the direction of travel of the particle beam. In other words, the thickness extension direction of the range adjustment plate 1 is parallel to the direction of travel of the particle beam, so that the particle beam passes through the range adjustment plate 1. The particle beam can be a proton beam. The material of the range adjustment plate 1 is boron-containing polyethylene or boron-containing polypropylene.

[0039] Boron-containing polyethylene or boron-containing polypropylene has the advantages of good light transmittance, light weight and heat resistance, plasticity, strong corrosion resistance, good wear resistance, high impact resistance, and low price. Boron-containing polyethylene or boron-containing polypropylene has good light transmittance, can effectively allow the particle beam to pass through the range adjustment plate 1, and will not cause excessive scattering or absorption of the particle beam, ensuring the high efficiency of the particle beam transmission of the radiotherapy equipment. The range adjustment plate 1 made of boron-containing polyethylene or boron-containing polypropylene can reduce the scattering of the particle beam, keep the increase of the beam spot of the particle beam small, and keep the beam spot of the particle beam as small as possible, thereby ensuring that the particle beam reaches the affected area stably and accurately with a small beam spot.

[0040] Boron-containing polyethylene or boron-containing polypropylene material has a relatively low density, so that the range shifter 100 has a relatively small overall weight and occupies a small space, thereby reducing the weight and volume of the radiotherapy equipment.

[0041] Boron-containing polyethylene or boron-containing polypropylene material has high heat resistance, and the range adjustment plate 1 can withstand high temperatures during the use of the radiotherapy equipment, thereby extending the service life of the range adjustment plate 1. At the same time, the performance of the range adjustment plate 1 can also remain stable, thereby extending the service life of the radiotherapy equipment and maintaining the performance of the radiotherapy equipment stable.

[0042] Boron-containing polyethylene or boron-containing polypropylene has good plasticity and can be made into range adjustment plates 1 of various shapes and sizes by heating and pressing to meet the needs of different radiotherapy equipment. Boron-containing polyethylene or boron-containing polypropylene range adjustment plates 1 are easy to manufacture, reducing manufacturing costs. The thickness of the range adjustment plates 1 is consistent, ensuring consistent adjustment performance at different positions of the range adjustment plates 1, improving the stability of the range adjustment plates 1. At the same time, the range adjustment plates 1 are highly flat, making the range adjustment plates 1 not only smoother in movement but also ensuring consistent adjustment performance at different positions of the range adjustment plates 1, improving the stability of the range adjustment plates 1.

[0043] Boron-containing polyethylene or boron-containing polypropylene has good corrosion resistance to common chemicals such as acid and alkali. The range adjustment plate 1 is not easily affected by the external environment, and the range adjustment plate 1 can maintain a long service life.

[0044] Boron-containing polyethylene or boron-containing polypropylene has excellent wear and impact resistance. The range adjustment plate 1 requires frequent movement during use. Boron-containing polyethylene or boron-containing polypropylene has excellent wear resistance, extending the service life of the range adjustment plate 1 and ensuring high stability during use. The range adjustment plate 1 is also prone to accidents such as collisions during installation or use. Boron-containing polyethylene or boron-containing polypropylene has excellent impact resistance, extending the service life of the range adjustment plate 1 and preventing damage from external impacts.

[0045] Multiple range adjustment plates 1 are arranged parallel to each other, which not only ensures that a fixed distance is maintained between adjacent range adjustment plates 1 to prevent adjacent range adjustment plates 1 from colliding during movement, but also prevents the particle beam from scattering or changing its direction when passing through the parallel range adjustment plates 1, ensuring that the particle beam reaches the affected area stably and accurately with a smaller beam spot.

[0046] There are gaps (not shown) between adjacent range adjustment plates 1 so that the movement of each range adjustment plate 1 will not interfere with or affect each other, ensuring smooth operation of the range adjustment plate 1 and avoiding jamming, and also improving the accuracy of position adjustment of the range adjustment plate 1.

[0047] The motion control mechanism 2 includes a plurality of drive devices 20 and a motion controller 25. The drive devices 20 and the motion controller 25 may be connected by wires or wirelessly. The motion controller 25 is used to control the drive devices 20, which are used to drive the range adjustment plate 1 to move. The drive devices 20 are used to move the range adjustment plate 1 into or out of the path of the particle beam to adjust the total thickness of the range adjustment plate 1 through which the particle beam passes. By adjusting the position of the range adjustment plate 1 and thus changing the total thickness of the range adjustment plate 1 through which the particle beam passes, the energy and range of the particle beam can be reduced or increased, allowing the particle beam to reach the affected area.

[0048] The multiple drive devices 20 preferably operate independently, with one drive device 20 preferably being used to drive one range adjustment plate 1. Each range adjustment plate 1 is provided with a separate drive device 20, enabling independent adjustment of each range adjustment plate 1, thereby preventing interference between the multiple range adjustment plates 1 and improving the speed and accuracy of range adjustment plate 1 adjustment. Furthermore, the range adjustment plates 1 can be combined in various ways, with different numbers of range adjustment plates 1 being able to create a variety of range adjustment plates 1 with varying total thicknesses. This expands the range of particle beam adjustment by the range adjustment plates 1, allowing the radiotherapy device to treat tumors within a wider range.

[0049] In some possible embodiments, the density of the boron-containing polyethylene is 1.95 to 2.15 g / cm 3 The density of boron-containing polypropylene is 1.93~2.13g / cm 3 By controlling the density of the boron-containing polyethylene or the boron-containing polypropylene, the boron content in the boron-containing polyethylene or the boron-containing polypropylene can be controlled. By controlling the boron content, the energy adjustment effect of the range adjustment plate 1 on the particle beam can be improved, thereby reducing the thickness of the range adjustment plate 1. It can also reduce the scattering of the particle beam, and keep the increase and decrease of the beam spot after the particle beam passes through small, thereby ensuring that the particle beam reaches the affected area stably and accurately with a smaller beam spot. It has been verified that the boron-containing polyethylene and boron-containing polypropylene with the above density can make the range adjustment plate 1 have a better adjustment effect.

[0050] Based on the width of the Bragg peak of the particle beam in water, different numbers or thicknesses of range adjustment plates 1 are combined to form combinations with different total thicknesses. Range adjustment plates 1 with different total thicknesses can enable the particle beam to reach affected areas at different locations.

[0051] In some possible embodiments, the thicknesses of the plurality of range adjustment plates 1 may be the same, which facilitates the production and installation of the range adjustment plates 1 , simplifies the combination of the plurality of range adjustment plates 1 , and facilitates the adjustment of the range adjustment plates 1 .

[0052] Alternatively, at least some of the range adjustment plates 1 may have different thicknesses. Specifically, some of the range adjustment plates 1 may have the same thickness, while others may have different thicknesses. Alternatively, all of the range adjustment plates 1 may have different thicknesses, as desired. Range adjustment plates 1 of varying thicknesses can be arranged and combined to form a variety of range adjustment plate 1 combinations with varying total thicknesses, further expanding the range of particle beam adjustment by the range adjustment plates 1, enabling the radiotherapy device to treat tumors within a wider range.

[0053] Each range adjustment plate 1 can also be divided into different areas, and the thickness of each area can also be different. In this way, more combinations of range adjustment plates 1 with different total thicknesses can be formed, further expanding the adjustment range of the range adjustment plate 1 on the particle beam, so that the radiotherapy equipment can treat tumors in a larger range.

[0054] Particle beam is a proton beam, along the proton beam direction (such as arrow direction among Fig. 1), the thickness of last range adjustment plate 1 that proton beam passes is maximum, the thickness difference of range adjustment plate 1 is set to according to under the proton beam nominal energy, Bragg peak width (80%-80%) is benchmark X in water, the equivalent water thickness of a plurality of range adjustment plates becomes multiple relation along the proton beam direction, and multiple relation is respectively 1 / 4X, 1 / 2X, 1X, 2X, 4X, 8X. Realize the regulation of range by the combination of different thicknesses range adjustment plate 1, so that reach the range of needs under different combination situations, the variation of combined state can satisfy the range regulation step-length of system.

[0055] In some possible embodiments, the range shifter 100 may further include a support base 3. The support base 3 is generally U-shaped, although other shapes are possible. The support base 3 has a first end 30 and a second end 31 that are opposite each other. The first end 30 and the second end 31 may be symmetrically arranged. A plurality of drive devices 20 are respectively arranged at the first end 30 and the second end 31 of the support base 3. The number of drive devices 20 at the first end 30 and the second end 31 is preferably the same, so that the overall structure of the range shifter 100 can be maintained more stable. Each drive device 20 includes a drive motor 201, an actuating bearing 202, and a brake 203. The third end 2021 of the actuating bearing 202 is disposed on the support base 3, the drive motor 201 is disposed at the fourth end 2022 of the actuating bearing 202, and the brake 203 is disposed below the drive motor 201. The brake 203 is connected to the range adjustment plate 1 and is sleeved on the actuating bearing 202. The driving motor 201 drives the actuating bearing 202, which drives the brake 203 to move up and down along the actuating bearing 202. The brake 203 then drives the range adjustment plate 1 to move up and down, moving the range adjustment plate 1 into or out of the path of the particle beam to adjust the total thickness of the range adjustment plate 1 through which the particle beam passes.

[0056] In some possible embodiments, the motion control mechanism 2 may further include a first position sensor 21, which is connected to the drive motor 201 and the motion controller 25. The first position sensor 21 is used to detect the rotational motion of the drive motor 201 to obtain position information of the range adjustment plate 1. The first position sensor 21 is, for example, a rotary encoder. The rotary encoder may be coupled to the drive motor 201. The rotary encoder may detect information such as the number of rotations and the direction of rotation of the drive motor 201 to obtain position information of the brake 203, and further obtain position information of the range adjustment plate 1. The rotary encoder may feed back the position information of the range adjustment plate 1 to the motion controller 25. The motion controller 25 controls the rotation of the drive motor 201 based on the feedback information from the rotary encoder, thereby accurately controlling the position of the range adjustment plate 1.

[0057] The motion control mechanism 2 may further include a second position sensor 22. Multiple second position sensors 22 are provided in the direction of motion of the brake 203. The second position sensors 22 are connected to the motion controller 25. The second position sensors 22 are used to detect the position of the brake 203 to obtain position information of the range adjustment plate 1. The second position sensor 22 may be, for example, a Hall effect switch. Multiple Hall effect switches may be provided in the direction of motion of each brake 203. Each brake 203 is provided with a sensing portion 2031. When the sensing portion 2031 moves to the position of the Hall effect switch, the Hall effect switch can feed back the position information of the range adjustment plate 1 to the motion controller 25. The motion controller 25 controls the rotation of the drive motor 201 based on the feedback information from the Hall effect switch, thereby further accurately controlling the position of the range adjustment plate 1.

[0058] In some possible implementations, the range shifter 100 may further include multiple slide rails 4 and adjustment brackets 5. The slide rails 4 are arranged one-to-one with the actuating bearings 202, and the number of slide rails 4 is the same as the number of actuating bearings 202. The range adjustment plate 1 is mounted on the adjustment bracket 5, with the fifth end 52 of the adjustment bracket 5 connected to the brake 203, and the sixth end 53 of the adjustment bracket 5 connected to the slide rails 4. This provides smoother and more stable movement of the range adjustment plate 1, and improves the accuracy of the movement of the range adjustment plate 1. In some possible implementations, the slide rails 4 and actuating bearing 202 are located at the same end of the support base 3, with the actuating bearing 202 closer to the outer edge of the support base 3. The adjustment bracket 5 is generally rectangular in shape, with a hollow portion 50 in the middle. The range adjustment plate 1 is mounted in the hollow portion 50 of the adjustment bracket 5 and secured by a snap-fit ​​structure 51. The snap-fit ​​structure 51 facilitates installation and removal of the range adjustment plate 1. Multiple snap-fit ​​structures 51 may be provided to enhance the stability of the range adjustment plate 1.

[0059] A third position sensor 23 may also be provided on the slide rail 4. Each slide rail 4 may be provided with a third position sensor 23. The third position sensor 23 is connected to the motion controller 25 and is used to obtain position information of the range adjustment plate 1. The third position sensor 23 may be, for example, a linear potentiometer. The linear potentiometer can obtain position information of the range adjustment plate 1 and feed the position information of the range adjustment plate 1 back to the motion controller 25. The motion controller 25 controls the rotation of the drive motor 201 based on the feedback information from the linear potentiometer, thereby further accurately controlling the position of the range adjustment plate 1.

[0060] The third position sensor 23 can be a sensor independent of the first sensor and the second sensor, which is equivalent to the range shifter 100 having two or more independent position feedback devices, ensuring the accuracy of the position of the range adjustment plate 1, thereby ensuring the accuracy of the particle beam adjustment by the range adjustment plate 1, and also ensuring that the range shifter 100 can operate stably, avoiding damage to one of the position feedback devices resulting in inaccurate position of the range adjustment plate 1, thereby improving the safety of the operation of the range shifter 100.

[0061] In some possible embodiments, the first position sensor 21, the second position sensor 22 and the third position sensor 23 can operate independently without interfering with each other, and can all feedback the position information of the range adjustment plate 1, thereby ensuring the accuracy of the position measurement of the range adjustment plate 1 and increasing the reliability of the system.

[0062] The range shifter 100 may further include a limiter 6 disposed above the range adjustment plate 1 to limit the range of movement of the range adjustment plate 1. In some possible implementations, the limiter 6 is disposed near the top of the range shifter 100, preferably flush with the first position sensor 21. This prevents the range adjustment plate 1 from moving beyond its range while ensuring sufficient room for movement.

[0063] The vertical movement range of the range adjustment plate 1 is preferably greater than twice the height of the range adjustment plate 1 , so that the position adjustment of the range adjustment plate 1 is more convenient.

[0064] Referring to Figure 3, a comparison of the total thicknesses of range adjustment plates 1 required for a 230 MeV particle beam, using range adjustment plates made of polycarbonate, graphite, and boron-containing polyethylene / propylene, is shown in a simulation test to reduce the energy of the beam to zero under identical test conditions. As can be seen from the figure, the thickness of the range adjustment plate 1 made of boron-containing polyethylene / propylene is the smallest, indicating that the range adjustment plate 1 made of boron-containing polyethylene / propylene has a better effect on reducing the energy of the particle beam. In other words, under the same conditions, the thickness of the range adjustment plate 1 made of boron-containing polyethylene / propylene can be thinner, thereby reducing the weight of the range adjustment plate 1.

[0065] Referring to Figure 4, a comparison of the beam spot sizes of particle beams produced when adjusting a 230 MeV energy particle beam to a 70 MeV energy particle beam using range adjustment plates 1 made of polycarbonate, graphite, and boron-containing polyethylene / propylene, respectively, under identical test conditions, is shown. As can be seen from the figure, the particle beam has the smallest beam spot when passing through the range adjustment plate 1 made of boron-containing polyethylene / propylene, indicating that the range adjustment plate 1 made of boron-containing polyethylene / propylene can reduce the scattering of the particle beam and maintain a stable beam spot, thereby ensuring that the particle beam reaches the affected area with a stable and precise small beam spot.

[0066] 5 , the present application further provides a method for controlling the range shifter 100 , which uses the range shifter 100 as described above and includes the following steps: S101 - S104 .

[0067] Step S101 : the motion controller 25 determines the required total thickness of the range adjustment plate 1 according to parameter information set by the system.

[0068] In some possible ways, the operator sets the system parameters according to information such as the location of the patient's affected area and the energy of the particle beam, and the motion controller 25 determines the required total thickness of the range adjustment plate 1 based on the parameter information set by the system.

[0069] Step S102 : the motion controller 25 controls the driving device 20 to move the required range adjustment plate 1 into the traveling path of the particle beam.

[0070] In some possible embodiments, the motion controller 25 controls the driving device 20 to move the required range adjustment plate 1 into the traveling path of the particle beam according to the total thickness of the required range adjustment plate 1 .

[0071] Step S103: the motion controller 25 determines the required total thickness of the range adjustment plate 1 again according to the changes in the system parameter information.

[0072] In some possible embodiments, the motion controller 25 re-determines the required total thickness of the range adjustment plate 1 according to changes in system parameter information, such as changes in the position of the patient's affected area and changes in the energy of the particle beam.

[0073] Step S104 : the motion controller 25 controls the driving device 20 to move the required range adjustment plate 1 into or out of the traveling path of the particle beam.

[0074] In some possible embodiments, the motion controller 25 controls the drive device 20 to move the required range adjustment plates 1 into the travel path of the particle beam according to the total thickness of the required range adjustment plates 1, and moves in or out certain range adjustment plates 1 based on the total thickness of the original range adjustment plates 1.

[0075] As a preferred embodiment, the motion controller 25 can also control the drive device 20 to move the range adjustment plate 1 that is not currently in use to the edge of the beam spot of the particle beam's path or a position outside the edge of the beam spot, based on the position of the particle beam, so as to reduce the adjustment distance of the range adjustment plate 1. When it is needed, it can be quickly moved to the designated position, thereby shortening the adjustment time of the range adjustment plate 1. The range adjustment plate 1 that has not been used can also be moved to the edge of the beam spot of the particle beam's path or a position outside the edge of the beam spot, so as to reduce the adjustment distance of the range adjustment plate 1. When it is needed, it can be quickly moved to the designated position, thereby shortening the adjustment time of the range adjustment plate 1. In some possible embodiments, the beam spot edge position can refer to a position that is 2.5 times the standard deviation of the beam spot Gaussian distribution.

[0076] The present application also provides a radiotherapy device, including a treatment gantry (not shown), a proton accelerator (not shown), a scanning magnet (not shown), an ionization chamber (not shown), and a range shifter 100 as described above. The radiotherapy device is configured to not have a beam transmission line, and the proton accelerator is mounted on the treatment gantry and can rotate with the treatment gantry. In some possible embodiments, the radiotherapy device is a proton therapy device, the accelerator can be a proton accelerator, the particle beam can be a proton beam, the flowing particle beam is referred to as a particle beam, and the particle beam can be a proton beam. The particle beam transmission system is used to transmit the particle beam from the accelerator to the patient's body. The particle beam transmission system is controlled by a magnetic field to accurately transmit the particle beam to the treatment position, ensuring accurate positioning and transmission of the particle beam. The particle beam transmission system may include components that the particle beam passes through during transmission, such as a scanning magnet, an ionization chamber, an adaptive aperture, etc. The scanning magnet allows the particle beam to move in the X direction and / or the Y direction by appropriately changing the magnetic field, and the X direction and the Y direction are perpendicular to each other. The ionization chamber can be used to measure the dose size and / or position of the beam. The adaptive grating can also become an adaptive aperture, which can be adaptively adjusted according to the shape and size of the target area, so that the shape and size of the particle beam can match the morphology of the tumor. The advantage of this adaptive irradiation is that it can better adapt to irregularly shaped tumors, thereby improving the personalization and targeting of the irradiation plan. The combination of components such as the scanning magnet, the ionization chamber, the range shifter 100 (also called the range adjuster or Range shifter) and the adaptive aperture can provide patients with accurate and flexible radiotherapy.

[0077] The accelerator is mounted on the treatment gantry and can rotate with it. This design reduces the complexity of the equipment because it eliminates the need for a beam transmission line, simplifying the equipment structure. This also improves beam stability. Because beam transmission lines inevitably introduce beam instability, radiotherapy equipment without beam transmission lines reduces maintenance costs and failure rates, improving equipment stability and reliability. By reducing the introduction of unstable factors, the beam movement is more stable, helping to maintain particle beam stability and ensure precise irradiation. The beam transmission line includes components such as a dipole magnet and / or a quadrupole magnet.

[0078] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are illustrative and cannot be understood as limiting the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the application without departing from the principles and purpose of the present application. All of these changes should fall within the scope of protection of the claims of the present application.

Claims

1. A range shifter, comprising: A plurality of range adjustment plates, wherein the plurality of range adjustment plates are arranged in parallel with each other, the range adjustment plates are used for allowing the particle beam to pass through, and the material of the range adjustment plates is boron-containing polyethylene or boron-containing polypropylene; A motion control mechanism, the motion control mechanism includes a plurality of driving devices and a motion controller, the motion controller is used to control the driving devices, the driving devices are used to drive the range adjustment plate, and the driving devices are used to move the range adjustment plate into or out of the travel path of the particle beam to adjust the total thickness of the range adjustment plate passed by the particle beam.

2. The range shifter according to claim 1, wherein: The density of the boron-containing polyethylene is 1.95-2.15 g / cm 3 The density of the boron-containing polypropylene is 1.93 to 2.13 g / cm 3 .

3. The range shifter according to claim 1, wherein: The thicknesses of the plurality of range adjustment plates are the same, or at least some of the range adjustment plates have different thicknesses. The particle beam is a proton beam. Along the direction of the proton beam, the thickness of the last range adjustment plate passed by the proton beam is the largest. The thicknesses of the range adjustment plates are set differently based on the Bragg peak width (80%-80%) in water at the nominal energy of the proton beam as a reference X. The equivalent water thicknesses of the plurality of range adjustment plates are in a multiple relationship along the direction of the proton beam, and the multiple relationships are 1 / 4X, 1 / 2X, 1X, 2X, 4X, and 8X, respectively.

4. The range shifter according to claim 1, wherein: It also includes a support base, which is U-shaped, and a plurality of drive devices are respectively arranged at the first end and the second end of the support base, each of the drive devices includes a drive motor, an actuating bearing and a brake, the third end of the actuating bearing is arranged on the support base, the drive motor is arranged at the fourth end of the actuating bearing, and the brake is connected to the range adjustment plate and sleeved on the actuating bearing.

5. The range shifter according to claim 4, wherein: The motion control mechanism further includes a first position sensor, which is connected to the drive motor and the motion controller, and is used to detect the rotational motion of the drive motor to obtain position information of the range adjustment plate.

6. The range shifter according to claim 4, wherein: The motion control mechanism also includes a second position sensor. A plurality of second position sensors are arranged in the motion direction of the brake. The second position sensors are connected to the motion controller and are used to detect the position of the brake to obtain position information of the range adjustment plate.

7. The range shifter according to claim 4, wherein: It also includes a plurality of slide rails and adjustment brackets, wherein the slide rails are arranged corresponding to the actuating bearings one by one, the range adjustment plate is arranged on the adjustment bracket, the fifth end of the adjustment bracket is connected to the brake, and the sixth end of the adjustment bracket is connected to the slide rail.

8. The range shifter according to claim 7, wherein: A third position sensor is arranged on the slide rail, the third position sensor is connected to the motion controller, and the third position sensor is used to obtain position information of the range adjustment plate.

9. The range shifter according to claim 1, wherein: It also includes a limiting device, which is arranged above the range adjustment plate and is used to limit the range of movement of the range adjustment plate; or Gaps are left between adjacent range adjustment plates so that the movements of each range adjustment plate will not interfere with or affect each other.

10. A method for controlling a range shifter, using the range shifter according to any one of claims 1 to 9, comprising the following steps: The motion controller determines the required total thickness of the range adjustment plate according to the parameter information set by the system; The motion controller controls the driving device to move the required range adjustment plate into the traveling path of the particle beam; The motion controller determines again the required total thickness of the range adjustment plate according to the change of the system parameter information; The motion controller controls the driving device to move the required range adjustment plate into or out of the traveling path of the particle beam.

11. The control method of the range shifter according to claim 10, wherein: The motion controller controls the driving device to move the range adjustment plate that is not currently needed to the beam spot edge position or a position outside the beam spot edge of the particle beam's travel path according to the position of the particle beam, so as to reduce the switching distance of the range adjustment plate combination.

12. A radiotherapy device, comprising a treatment gantry, a proton accelerator, a scanning magnet, an ionization chamber, and a range shifter as claimed in any one of claims 1 to 9, wherein the radiotherapy device is configured without a beam transmission line, and the proton accelerator is mounted on the treatment gantry and can rotate with the treatment gantry.

Images