Particle accelerator beam calibration system and calibration method
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- MEVION MEDICAL EQUIPMENT CO LTD
- Filing Date
- 2024-08-07
- Publication Date
- 2026-06-26
Smart Images
Figure CN120617840B_ABST
Abstract
Description
[0001] This application is a divisional application of Chinese application No. 202411077006.9, filed on August 7, 2024, entitled "Particle Accelerator Beam Calibration System and Calibration Method". Technical Field
[0002] This invention relates to the field of particle radiotherapy equipment technology, and in particular to a particle accelerator beam calibration system and calibration method. Background Technology
[0003] Proton therapy is a type of radiotherapy that uses high-energy particles to target and destroy tumor cells and other tumors within a patient's body. The high-energy particles in proton therapy are primarily produced by accelerating protons using a particle accelerator to form a proton beam. This beam exits through the accelerator's outlet to destroy the tumor cells and other tumors within the patient's body.
[0004] Proton therapy equipment typically involves manufacturing and partially assembling various required components in a factory, followed by final assembly at the hospital to form the complete device. Because proton therapy equipment has strict requirements regarding the beam's exit direction, any deviation in the beam's path can prevent it from accurately and effectively targeting tumor cells and other sites within the patient's body, thus affecting treatment outcomes. Therefore, proton therapy equipment requires commissioning during hospital construction, particularly the particle accelerator used to generate the beam, to ensure the beam's exit path meets requirements. However, commissioning at the hospital is a lengthy process, consequently extending the overall construction period for installing the proton therapy equipment within the hospital. Summary of the Invention
[0005] The purpose of this invention is to provide a particle accelerator beam calibration system and calibration method for pre-calibrating particle accelerator beams, thereby reducing the calibration cycle when particle accelerators are installed in hospitals.
[0006] The objective of this invention is achieved through the following technical solution:
[0007] A particle accelerator beam calibration system, comprising:
[0008] A bracket assembly for mounting on a recessed surface and for providing driving force;
[0009] A particle accelerator is provided with a rotation axis and a beam outlet for emitting a beam. The particle accelerator is directly or indirectly connected to the support assembly and is suspended above a pit on the ground. Under the driving force of the support assembly, it can rotate around the rotation axis.
[0010] A calibration component, mounted on the particle accelerator and capable of rotating with it, is used for beam calibration of the particle accelerator before it leaves the factory. The calibration component has a through-flow extension channel, the straight line of which does not intersect the rotation axis. One end of the calibration component extends horizontally to the isocenter point of the calibration system, forming an indicator section. The other end is directly or indirectly connected to the beam exit port to guide the beam leaving the particle accelerator along the extension channel. The indicator section indicates the position of the isocenter point corresponding to the particle accelerator during rotation. The indicator section has multiple marker points; when the particle accelerator rotates, the intersection of the projections of these marker points indicates the position of the isocenter point corresponding to the particle accelerator.
[0011] The particle accelerator is located above the pit, and the pit is connected to the space above the ground to form the rotation space of the calibration component; the beam calibration system is used to pre-calibrate the particle accelerator, and the calibration component indicates the calibration of the particle accelerator by indicating the position of the isocenter point and the position offset of the path of the particle accelerator's output beam. After calibration, the particle accelerator is moved to the proton therapy system.
[0012] Preferably, the calibration assembly includes an interconnected mounting base and an extension rod, the mounting base being mounted on the particle accelerator, and the indicator portion being disposed at one end of the extension rod.
[0013] Preferably, the extension rod further includes a rod body portion, and the indicator portion is mounted on the rod body portion and can be locked to the rod body portion in multiple positions;
[0014] And / or, the calibration system further includes a cylinder connected to the particle accelerator and rotatably mounted on the support assembly so that the particle accelerator can rotate relative to the support assembly via the cylinder.
[0015] Preferably, the indicator includes multiple indicator surfaces, each of which is provided with a marker point. The multiple marker points are projected together onto the isocenter point corresponding to the particle accelerator to indicate the position of the isocenter point corresponding to the particle accelerator.
[0016] Preferably, the indicating surface is provided with crosshair scale lines, and the intersection of the crosshair scale lines forms the marking point;
[0017] The calibration system also includes a laser lamp for generating a cross laser beam. The laser lamp is positioned corresponding to the indicator surface, and the cross laser beam is able to coincide with the cross scale lines of the indicator surface.
[0018] Preferably, it also includes a wall, and the laser light is adjustablely mounted on the wall;
[0019] The particle accelerator is provided with a central marker line, and at least one of the laser lamps generates a cross laser beam that coincides with the central marker line.
[0020] A particle accelerator beam calibration method, applied to any of the above-mentioned particle accelerator beam calibration systems, the calibration method comprising:
[0021] Mount the particle accelerator onto the support assembly and rotate the particle accelerator to its initial position;
[0022] Install the calibration component and adjust its position so that the indicator part of the calibration component can indicate the position of the isocenter point corresponding to the particle accelerator;
[0023] The particle accelerator is rotated and the particle accelerator emits beams at multiple angles. The offset of the beam at multiple rotation angles is determined by the positional deviation between the beam and the isocenter point indicated by the indicator.
[0024] The particle accelerator is adjusted to correct the exit path of the beam generated by the particle accelerator.
[0025] Preferably, the step of mounting the particle accelerator on the support assembly and rotating the particle accelerator to the initial position specifically includes: mounting the particle accelerator on the cylinder and rotatably mounting the cylinder on the support assembly, and rotating the cylinder to rotate the particle accelerator to a horizontal position.
[0026] Preferably, the installation of the calibration component and adjustment of its position specifically includes:
[0027] A first laser lamp is installed facing the exit beam of the particle accelerator, and second laser lamps are installed on both sides of the particle accelerator.
[0028] Install the calibration component and adjust the position of the indicator part of the calibration component according to the laser generated by the first laser lamp;
[0029] Adjust the position of the second laser light so that the laser light generated by the second laser light corresponds to the indicator.
[0030] Preferably, the installation of the first laser lamp facing the exit port of the particle accelerator specifically includes: installing the first laser lamp at the position where the beam generated by the particle accelerator irradiates the wall, and aligning the laser generated by the first laser lamp with the center mark line of the particle accelerator;
[0031] The installation of the calibration component and the adjustment of the position of the indicator of the calibration component according to the laser generated by the first laser lamp specifically includes: adjusting the position between the indicator surface of the indicator facing the first laser lamp and the first laser lamp, so that the crosshair of the indicator surface facing the first laser lamp coincides with the laser generated by the first laser lamp, and locking the calibration component.
[0032] Preferably, adjusting the particle accelerator to calibrate the exit path of the beam generated by the particle accelerator specifically includes:
[0033] Determine whether the offset of the beam in the first direction at each rotation angle exceeds a threshold. If the offset of the beam in the first direction exceeds the threshold, adjust the path of the beam in the first direction.
[0034] The offset of the beam in the second direction at multiple rotation angles is obtained, and the particle accelerator is adjusted according to the offset of the beam in the second direction at multiple rotation angles.
[0035] The first direction is parallel to the axis of the cylinder, and the first direction and the second direction are perpendicular to each other.
[0036] Preferably, adjusting the particle accelerator according to the offset of the beam in the second direction at multiple rotation angles specifically includes:
[0037] Calculate the deflection angle β of the particle accelerator, where the deflection angle β = arctan a / b, a is the average of the maximum and minimum values among multiple deflections of the beam in the second direction, and b is the source axis distance of the particles in the particle accelerator.
[0038] The relative position of the particle accelerator and the cylinder is adjusted according to the deflection angle β of the particle accelerator.
[0039] Compared with the prior art, the beneficial effects of the present invention include at least the following:
[0040] By configuring the particle accelerator to rotate around its axis of rotation, beam output at different angles can be achieved within a relatively small space. By incorporating a calibration component that rotates with the particle accelerator, the component can indicate the position of the accelerator's isocenter in real time, thereby determining the beam offset at multiple angles. This allows for corresponding beam adjustments within the factory, reducing the adjustment cycle during hospital installation after the particle accelerator leaves the factory. Furthermore, by creating a recess in the ground that connects to the space above, forming a rotation space for the calibration component, interference between the component and the ground can be prevented when rotating within the limited space of the factory. Attached Figure Description
[0041] Figure 1 This is a partial structural schematic diagram of the particle accelerator beam calibration system according to an embodiment of the present invention;
[0042] Figure 2 This is a schematic diagram of the structure of the calibration component according to an embodiment of the present invention;
[0043] Figure 3 This is an exploded view of the calibration component according to an embodiment of the present invention;
[0044] Figure 4 This is a schematic diagram of the calibration component from another perspective according to an embodiment of the present invention;
[0045] Figure 5 This is a schematic diagram of the structure of the indicator part according to an embodiment of the present invention.
[0046] In the diagram: 1. Support assembly; 11. Support frame; 12. Support foot; 2. Particle accelerator; 3. Calibration assembly; 31. Mounting base; 32. Extension rod; 321. Extension channel; 322. Rod body; 323. Indicator; 3231. Indicator surface; P. Marker point; 3232. Waist-shaped groove; 4. Cylinder; 51. First laser light; 52. Second laser light. Detailed Implementation
[0047] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided to make the invention more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore repeated descriptions of them will be omitted.
[0048] The terms used to express position and direction in this invention are illustrated with reference to the accompanying drawings, but changes can be made as needed, and all such changes are included within the scope of protection of this invention.
[0049] like Figure 1 As shown, this invention provides a particle accelerator beam calibration system, which can be used to calibrate a particle accelerator 2 in a proton therapy device to adjust the exit path of the particle accelerator 2 beam, thereby ensuring that the beam path of the particle accelerator 2 at various angles meets factory requirements. The particle accelerator beam calibration system of this application can be used in a factory, and this calibration system does not require the pre-construction of a treatment room for installing the proton therapy device. The particle accelerator beam calibration system includes a support assembly 1, a particle accelerator 2 directly or indirectly connected to the support assembly 1 and capable of rotating relative to the support assembly 1, a calibration assembly 3 mounted on the particle accelerator 2, and may also include a cylinder 4 connected to the particle accelerator 2.
[0050] The support assembly 1 can be fixed to a recessed surface in the calibration system, and can provide driving force for the particle accelerator 2 to rotate. Specifically, when the calibration system is used in a factory, the factory floor can be provided with recesses, and the support assembly 1 can be installed on the recessed surface, with the superconducting magnet in the particle accelerator 2 located directly above the recess. The recesses ensure that components mounted directly or indirectly on the support assembly 1 (e.g., the superconducting magnet in the particle accelerator 2) do not interfere with the ground when rotating relative to the support assembly 1.
[0051] The bracket assembly 1 may include a pair of support frames 11, each support frame 11 including a pair of support legs 12 that contact the ground. The support legs 12 can be fixed to the ground by screws or other locking devices. By controlling the installation position of the support legs 12 when they are installed on the ground, the installation position of the bracket assembly 1 can be controlled.
[0052] In some specific embodiments, a pair of cylinders 4 may be provided, with one end of each cylinder 4 connected to the particle accelerator 2 and the other end rotatably connected to a support frame 11 in the support assembly 1. Specifically, the pair of cylinders 4 are arranged on opposite sides of the particle accelerator 2 and together clamp and fix the particle accelerator 2. A pair of support frames 11 are arranged on opposite sides of the whole formed by the pair of cylinders 4 and the particle accelerator 2, and each support frame 11 is connected to a corresponding cylinder 4 and can drive the cylinder 4 to rotate, so that the cylinder 4 is rotatably connected to the support frame 11. The cylinder 4 can rotate about its axis, and the axes of the pair of cylinders 4 coincide. The rotatable connection between the support frame 11 and the cylinder 4 can be achieved by existing common rotating structures, and the connection between the cylinder 4 and the particle accelerator 2 can adopt the connection method common in proton therapy systems, so it will not be described in detail here. In addition, the cylinder 4 can be supported by the support frame 11 and thus suspended relative to the pit on the ground in the calibration system. The axis can also be called the rotation axis, and the direction of the rotation axis is the X direction.
[0053] The particle accelerator 2 is used to accelerate particles to form a beam. The particle accelerator 2 has a rotation axis and a beam exit port for ejecting the beam. The particle accelerator 2 is mounted on the cylinder 4 so that it can be indirectly supported by the support assembly 1 and suspended relative to the recess. The rotation axis of the particle accelerator 2 can be parallel to the axis of the cylinder 4. When the support assembly 1 drives the cylinder 4 to rotate, it simultaneously drives the particle accelerator 2 mounted on the cylinder 4 to rotate synchronously. At this time, the particle accelerator 2 can rotate around its axis of rotation around the cylinder 4. In other embodiments, if the axis of the cylinder 4 is not parallel to and does not coincide with the rotation axis of the particle accelerator 2, the cylinder 4 is used to transmit the rotational driving force provided by the support assembly 1 to the particle accelerator 2, so that the particle accelerator 2 rotates around its rotation axis. Specifically, the particle accelerator 2 can be a proton accelerator 2, and the particles can be protons. The axis of particle accelerator 2, i.e., the central axis, can coincide with the axis of cylinder 4, i.e., the central axis. The central axis can also be called the rotation axis of particle accelerator 2.
[0054] When installing a proton therapy system, particle accelerator 2 is installed in the hospital's treatment room. The treatment room comprises three layers, with the second layer serving as the isocenter. Particle accelerator 2 needs to rotate around this isocenter and generate beams at multiple angles to target and destroy tumor cells and other tumor sites within the patient's body. Therefore, adjustments to the proton therapy system are necessary to ensure that the beam paths generated by particle accelerator 2 meet the requirements at these angles. Commissioning the proton therapy system in the hospital is time-consuming, and the limited availability of adjustment equipment in hospitals hinders commissioning efficiency. Furthermore, if components such as the particle accelerator require rework during commissioning, the dismantling and transportation of these components further delays the system's construction. Because the construction cost of treatment rooms for installing proton therapy equipment is high, existing factories do not construct separate treatment rooms, making it impossible for them to perform the same commissioning operations as those used in hospitals.
[0055] In this application, by configuring the particle accelerator 2 to rotate relative to the support assembly 1 about its rotation axis, the particle accelerator 2 can rotate without requiring a large space; that is, the particle accelerator 2 can rotate within a factory, thereby simulating the rotation of the particle accelerator 2 around the isocenter point of the treatment room in a hospital. During the rotation of the particle accelerator 2, the position of the calibration system and the isocenter point corresponding to the particle accelerator 2 also rotates. For example, the particle accelerator 2 can rotate 0-190° around its rotation axis, and the isocenter point corresponding to the particle accelerator 2 will also rotate 0-190° around the rotation axis of the particle accelerator 2. To enable the calibration assembly 3 to indicate the position of the isocenter point corresponding to the particle accelerator 2 in real time during the rotation of the particle accelerator 2, this application employs a calibration assembly 3 installed on the particle accelerator 2 that can be used to indicate the isocenter position of the particle accelerator 2. The calibration assembly 3 can rotate with the particle accelerator 2 to indicate the position of the isocenter point corresponding to the particle accelerator 2 in real time during the rotation of the particle accelerator 2. When calibrating particle accelerator 2, it can drive calibration component 3 to rotate together. This rotation simulates the process of particle accelerator 2 rotating during radiotherapy. The path of the beam exiting particle accelerator 2 can be recorded at multiple angles to determine if there is any deviation from the isocenter position, and by how much. This allows for corresponding adjustments to particle accelerator 2. The isocenter position of particle accelerator 2 represents the intended location for the particle accelerator 2 beam to treat the patient. Specifically, when particle accelerator 2 is installed in the hospital and rotated to the same angle, its isocenter position is set to coincide with the isocenter point of the treatment room. As particle accelerator 2 rotates 0-190° around its axis of rotation, calibration component 3 also rotates synchronously within the same range. Calibration component 3 can rotate within the recessed area on the calibration system floor and the space above it. By allowing calibration component 3 to rotate within the recessed area, interference between calibration component 3 and the floor during rotation is avoided.
[0056] By cooperating with the calibration component 3 and the particle accelerator 2, when the particle accelerator 2 rotates to different angles, the beam path of the particle accelerator 2 can be calibrated by judging whether the beam of the particle accelerator 2 deviates from the position of the isocenter point indicated by the calibration component 3 at the corresponding angle, and by the magnitude of the deviation. This simple structure, small footprint, and low cost allow the particle accelerator 2 to be initially debugged in the factory. Disassembly or reprocessing during the debugging process can also be performed directly in the factory, significantly reducing the debugging cycle of the particle accelerator 2's beam path. After the beam path of the particle accelerator 2 is adjusted, the particle accelerator 2 and the cylinder 4 can be transported as a whole to the hospital for installation, effectively reducing the debugging cycle of the proton therapy system during hospital construction, and thus effectively reducing the construction cycle of the proton therapy system in the hospital, facilitating the faster application of the particle accelerator for radiotherapy and benefiting the public.
[0057] Reference Figure 2 and Figure 3 To enable the calibration component 3 to indicate the isocenter position corresponding to the particle accelerator 2, one end of the calibration component 3 can extend horizontally to the isocenter position corresponding to the particle accelerator 2 and form an indicator 323. The indicator 323 can indicate a virtual point, which can coincide with the isocenter position corresponding to the particle accelerator 2, thereby enabling the indicator 323 to indicate the isocenter position corresponding to the particle accelerator 2. When the particle accelerator 2 rotates, the indicator 323 of the calibration component 3 will rotate synchronously with the particle accelerator 2, and the virtual point indicated by the indicator 323 will rotate with the particle accelerator 2, so that the isocenter position corresponding to the particle accelerator 2 can be indicated when the particle accelerator 2 rotates to different angles.
[0058] Reference Figure 4 and Figure 5Specifically, the indicator unit 323 may include multiple mutually perpendicular indicator surfaces 3231. Each indicator surface 3231 is provided with a marker point P. The marker point P of each indicator surface 3231 can be projected onto the isocenter point corresponding to the particle accelerator, so that the intersection point formed by the projections of the marker points P of the multiple indicator surfaces 3231 can indicate the isocenter point corresponding to the particle accelerator 2. That is, when the particle accelerator 2 rotates, the position of the isocenter point corresponding to the particle accelerator 2 can be indicated by the intersection point formed by the projections of the marker points P of the multiple indicator surfaces 3231. For example, when the indicator surface 3231 is perpendicular to the beam emission path, the projection of the marker point P on the indicator surface 3231 in the opposite direction of the beam emission path can coincide with the isocenter point of the calibration system; when the indicator surface 3231 is parallel to the beam emission path, the projection of the marker point P on the indicator surface 3231 in the direction perpendicular to the beam emission path can coincide with the isocenter point of the calibration system. The projection direction of the indicator 323 can be perpendicular to the indicator surface 3231 on which the indicator 323 is located. The indicator surface 3231 can also be provided with multiple intersecting scale lines, and the intersection of the multiple scale lines forms a mark point P on the indicator surface 3231; for example, a cross scale line can be provided on the indicator surface 3231, and the intersection of the cross scale line forms a mark point P on the indicator surface 3231. The cross scale lines of the indicator surface 3231 can actually intersect, so that the actual intersection of the cross scale lines forms a mark point P, or the cross scale lines of the indicator surface 3231 are empty in the middle, and the virtual intersection of the virtual extension lines of the cross scale lines forms a mark point P.
[0059] In the initial state, the virtual point indicated by the indicator 323 is ensured to coincide with the corresponding isocenter position of the particle accelerator 2 in the initial state. Then, when the particle accelerator 2 rotates, the isocenter position of the particle accelerator 2 and the position of the indicator 323 of the calibration component 3 will move synchronously around the axis of the cylinder 4, so that the isocenter position of the particle accelerator 2 and the virtual point indicated by the indicator 323 remain in the same state during the rotation. Therefore, the indicator 323 can indicate the isocenter position of the particle accelerator 2 in real time during the rotation of the particle accelerator 2.
[0060] Reference Figure 3In some specific embodiments, the calibration component 3 includes a mounting base 31 and an extension rod 32 connected to each other. The mounting base 31 may be integrally formed with the extension rod 32. The mounting base 31 may be mounted on the particle accelerator 2, for example, on the outer shell or yoke of the particle accelerator 2. One end of the extension rod 32 is integrally connected to the mounting base 31, and the other end may extend to the isocenter position corresponding to the particle accelerator 2 and be provided with an indicator 323 for indicating the isocenter position of the particle accelerator 2. Specifically, the extension rod 32 may include a rod body 322 and an indicator 323. One end of the rod body 322 is integrally connected to the mounting base 31, and the other end extends horizontally to the isocenter position corresponding to the particle accelerator 2. The indicator 323 is mounted on the end of the rod body 322 facing the isocenter position corresponding to the particle accelerator 2, so that the indicator 323 can indicate the isocenter position of the particle accelerator 2. The extension rod 32 contains a straight, continuous extension channel 321. One end of the extension channel 321 connects to the beam outlet of the particle accelerator 2, and the other end extends to the indicator 323. When the particle accelerator 2 emits a beam, the beam can be transmitted to the indicator 323 through the extension channel 321. The straight line containing the extension channel 321 does not intersect the rotation axis of the particle accelerator 2, ensuring accurate alignment and guidance between the extension channel 321 and the beam. The straight line containing the extension channel 321 is the direction of beam propagation, i.e., the Y-direction. The Z-direction is perpendicular to both the X and Y directions, and the X and Y directions are mutually perpendicular.
[0061] In some specific embodiments, to intuitively, efficiently, and accurately determine the offset between the beam of the particle accelerator 2 and the position of its corresponding isocenter point, the indicator 323 is provided with a projection surface. The beam of the particle accelerator 2 is projected onto the projection surface to form an image corresponding to the beam, such as a beam spot image. The offset of the particle accelerator 2 beam is obtained by observing the position of the beam spot image generated on the projection surface and the position deviation of the virtual point indicated by the indicator 323. The projection surface can be fitted and parallel to the indicator surface 3231 in the indicator 323, which is perpendicular to the beam direction.
[0062] Reference Figure 4 and Figure 5In some specific embodiments, the indicator portion 323 can be locked to the rod portion 322 in multiple positions. Specifically, the indicator portion 323 may have a waist-shaped groove 3232, which can extend in a horizontal or vertical direction. The indicator portion 323 can be fixed to the rod portion 322 by a fastener such as a screw passing through the waist-shaped groove 3232. When installing the indicator portion 323, the screw can slide within the waist-shaped groove 3232 along the extension direction of the waist-shaped groove 3232, so that the screw can press the indicator portion 323 at different positions, thereby locking the indicator portion 323 at multiple different positions relative to the rod portion 322, thus realizing the adjustment of the position of the indicator portion 323.
[0063] Reference Figure 1 To facilitate adjustment of the position of the indicator 323 in the calibration component 3, the calibration system also includes laser lights. Multiple laser lights can be provided, and each laser light can be correspondingly positioned with an indicator surface 3231, so that each laser light can emit laser light onto its corresponding indicator surface 3231, and the laser beams emitted by multiple laser lights can intersect at a virtual point indicated by the indicator 323. The laser lights are adjustablely mounted within a wall in the calibration system, allowing them to be locked at multiple different positions relative to the wall, which can specifically be a wall within a factory. The laser lights can generate cross-shaped laser beams, and the indicator surface 3231 is provided with cross-shaped scale lines. When the calibration component 3 is adjusted, the cross-shaped laser beams emitted by each laser light coincide with the cross-shaped scale lines of the corresponding indicator surface 3231. Specifically, the laser lights can include a first laser light 51 and a second laser light 52. The first laser light 51 can be directly facing the beam outlet of the particle accelerator 2, and the second laser light 52 can be located on opposite sides of the particle accelerator 2 along the axial direction of the cylinder 4.
[0064] In some embodiments, the particle accelerator 2 has a center marking line at its axial center position, which can be used to indicate the installation position of the laser lamp. The center marking line can be a connecting seam formed during the assembly of a pair of yokes in the particle accelerator 2, extending circumferentially and located at the center of the particle accelerator 2. The vertical portion of the crosshair laser line generated by at least one laser lamp can coincide with the center marking line of the particle accelerator 2, so that the center marking line can indicate the installation position of the corresponding laser lamp; for example, the vertical portion of the crosshair laser line generated by the first laser lamp 51 can coincide with the center marking line of the particle accelerator 2, so that the center marking line can indicate the installation position of the first laser lamp 51.
[0065] The present invention also provides a particle accelerator beam calibration method, which is applied to the aforementioned particle accelerator beam calibration system. The particle accelerator beam calibration method may include steps S01 to S04.
[0066] Step S01: Install the particle accelerator 2 onto the support assembly 1 and rotate the particle accelerator 2 to its initial position.
[0067] Step S02: Install calibration component 3 and adjust the position of calibration component 3 so that the indicator part 323 of calibration component 3 can indicate the isocenter point corresponding to particle accelerator 2.
[0068] Step S03: Rotate the cylinder 4 and make the particle accelerator 2 emit beams at multiple angles, and determine the offset of the beam at multiple rotation angles by the positional deviation between the beam and the isocenter point indicated by the indicator 323.
[0069] Step S04: Adjust particle accelerator 2 to correct the exit path of the beam generated by particle accelerator 2.
[0070] Step S01 specifically includes: installing the particle accelerator 2 onto the cylinder 4 and rotatably mounting the cylinder 4 onto the support assembly 1. Rotating the cylinder 4 to a horizontal position so that the particle accelerator 2 is in its initial position. The rotation angle of the cylinder 4 can range from 0 to 190°. The horizontal position of the cylinder 4 corresponds to its horizontal alignment with the isocenter point of the treatment room in the hospital. The horizontal position of the cylinder 4 can be achieved when it rotates to 90° or approximately 90°; specifically, the horizontal position of the cylinder 4 is achieved when it rotates to 89.9-90.1°. The rotation angle of the cylinder 4 can be measured using an angle measuring instrument to ensure that the cylinder 4 is rotated to a horizontal position.
[0071] Step S02 specifically includes steps S21 to S23.
[0072] Step S21: Install a first laser lamp 51 facing the exit beam of the particle accelerator 2, and install a second laser lamp 52 on each of the opposite sides of the particle accelerator 2. Specifically, when the particle accelerator 2 is in its initial position, the beam generated by the particle accelerator 2 will strike the wall. The first laser lamp 51 is installed at the point where the beam strikes the wall, so that the first laser lamp 51 faces the exit beam of the particle accelerator 2. Then, the position of the first laser lamp 51 along a first direction is adjusted, for example, adjusting the position of the first laser lamp 51 along the first direction so that the vertical part of the cross laser generated by the first laser lamp 51 coincides with the center mark line of the particle accelerator 2. The first direction can be parallel to the axis of the cylinder 4.
[0073] Since the particle accelerator 2 is roughly circular in shape with a circular center marking line, and the first laser lamp 51 is located on one side of the particle accelerator 2, the laser emitted by the first laser lamp 51 can coincide with the portion of the center marking line on the side of the particle accelerator 2 facing the first laser lamp 51. Whether the portion of the center marking line on the particle accelerator 2 facing away from the first laser lamp 51 coincides with the laser emitted by the first laser lamp 51 can be determined by a plumb line. For example, the plumb line can be located on the side of the particle accelerator 2 facing away from the first laser lamp 51, and the plumb line can be parallel to the portion of the center marking line on the particle accelerator 2 facing away from the first laser lamp 51. A portion of the plumb line can pass through the particle accelerator 2 and be located below the particle accelerator 2, so that the portion of the plumb line below the particle accelerator 2 is not blocked by the particle accelerator 2 and can be irradiated by the laser emitted by the first laser lamp 51. By determining whether the laser emitted by the first laser lamp 51 coincides with the portion of the plumb line below the particle accelerator 2, it can be determined whether the laser emitted by the first laser lamp 51 coincides with the portion of the center marking line on the particle accelerator 2 facing away from the first laser lamp 51. When the laser generated by the first laser lamp 51 can coincide with the part of the center mark line of the particle accelerator 2 facing the first laser lamp 51 and the part of the center mark line of the particle accelerator 2 facing away from the first laser lamp 51, the position adjustment of the first laser lamp 51 along the first direction is completed.
[0074] The second laser lamp 52 can be positioned at the projection location on the corresponding wall along the first direction of the intersection point of the laser generated by the first laser lamp 51 and the center point of the particle accelerator 2. A pair of second laser lamps 52 are symmetrically arranged relative to the particle accelerator 2 along the first direction.
[0075] Step S22: Install the calibration component 3 and adjust the position of the indicator 323 of the calibration component 3 according to the laser generated by the first laser lamp 51. Specifically, the calibration component 3 is installed on the particle accelerator 2 and is set horizontally. At this time, the mounting base 31 and the extension rod 32 in the calibration component 3 are both in a horizontal state. The calibration component 3 can be measured with a level to ensure that the calibration component 3 is in a horizontal state. When the calibration component 3 is horizontal, the calibration component 3 is at 90° or approximately 90°, for example, the calibration component 3 is at 89.9-90.1°, that is, the mounting base 31 and the extension rod 32 are at 89.9-90.1° respectively.
[0076] After the calibration assembly 3 is installed in the particle accelerator 2, the first laser lamp 51 is turned on so that it emits laser light towards the calibration assembly 3. The position of the first laser lamp 51 is adjusted so that the horizontal portion of the cross laser light generated by the first laser lamp 51 coincides with the horizontal portion of the cross scale on the indicator surface 3231 of the indicator 323, and the first laser lamp 51 is locked. The screws used to lock the indicator 323 in the calibration assembly 3 are loosened, and the position of the indicator 323 is adjusted so that the vertical portion of the cross scale on the indicator surface 3231 of the indicator 323 coincides with the vertical portion of the cross laser light generated by the first laser lamp 51, and the indicator 323 is locked.
[0077] When the calibration component 3 is in a horizontal state, the horizontal part of the cross scale of the indicator surface 3231 is the horizontal scale line in the cross scale, and the vertical part is the vertical scale line in the cross scale; the horizontal part of the cross laser generated by the laser lamp is the horizontal laser in the cross laser, and the vertical part is the vertical laser in the cross laser.
[0078] Step S23: Adjust the pair of second laser lights 52 so that the cross laser beams generated by the second laser lights 52 coincide with the cross scale of the corresponding indicator surface 3231, and lock the pair of second laser lights 52. At this time, the indicator mark of the calibration component 3 can indicate the isocenter point of the calibration system.
[0079] In step S03, the cylinder 4 can rotate in steps of 22.5°. Each rotation of the cylinder 4 measures the beam offset generated by the particle accelerator 2. Specifically, after the indicator mark of the calibration component 3 indicates the isocenter point of the calibration system, the cylinder 4 is rotated successively to nine angles: 0°, 22.5°, 45°, 67.5°, 90°, 112.5°, 135°, 157.5°, and 180°, and the beam offset at each of these nine angles is obtained.
[0080] Step S04 specifically includes: each time the beam offset is measured, determining whether the beam offset along the first direction exceeds a threshold; if the beam offset along the first direction exceeds the threshold, adjusting the beam to ensure that the beam offset in the first direction meets the requirements. Each time the beam offset is measured, recording the beam offset along the second direction; after measuring the beam offset along the second direction at multiple angles, adjusting the particle accelerator 2 based on the beam offset along the second direction at multiple angles.
[0081] The threshold for the beam offset along the first direction is 1 mm. When the beam offset along the first direction exceeds the threshold, it is adjusted by adjusting the diode magnet in the beam extraction channel of the particle accelerator 2. The second direction can be perpendicular to the first direction, and the second direction can be perpendicular or approximately perpendicular to the beam direction of the particle accelerator 2.
[0082] The particle accelerator 2 is adjusted by measuring the beam offset along the second direction at multiple angles. Specifically, the deflection angle β of the particle accelerator 2 is calculated using the beam offset along the second direction at multiple angles. The deflection angle β = arctan a / b, where a is the average of the maximum and minimum values of the beam offset along the second direction, and b is the SAD (source axis distance) of the particles in the particle accelerator 2. The relative position of the particle accelerator 2 and the cylinder 4 is then adjusted based on the deflection angle β.
[0083] As a specific example, when the cylinder 4 is rotated successively to nine angles—0°, 22.5°, 45°, 67.5°, 90°, 112.5°, 135°, 157.5°, and 180°—the beam deflection along the second direction is successively -30mm, -26mm, -27mm, -35mm, -31mm, -25mm, -29mm, -28mm, and -33mm. The maximum and minimum beam deflection along the second direction are -35mm and -25mm, respectively, where 'a' is 30mm. The SAD of miniaturized protons is typically around 2000mm; here, 'b' is set to 2000mm. At this point, the deflection angle β = arctan(-30 / 2000), which is -0.859°. The particle accelerator 2 is then rotated so that it rotates -0.859° relative to the cylinder 4. The calibration component 3 has an indicator 323 with a first end and a second end opposite each other along a second direction. For example, in the initial state, the first end of the indicator 323 is located above the second end. The offset of the beam relative to the isocenter point of the calibration system toward the first end is a positive offset, and the offset of the beam relative to the isocenter point of the calibration system toward the second end is a negative offset. When the deflection angle β is -0.859°, the particle accelerator 2 can rotate 0.859° in the negative direction, i.e., toward the second end.
[0084] After the position of particle accelerator 2 is adjusted according to the deflection angle β, steps S01 to S03 are executed again to ensure that the beam path meets the requirements after adjustment. For example, the beam offset along the first direction does not exceed 1 mm, and the beam offset along the second direction does not exceed 1 mm. At this point, the beam calibration of particle accelerator 2 is complete, ensuring precise particle radiotherapy in the future. The particle accelerator 2 and the cylinder 4 can then be transported to the hospital for final assembly and testing of the proton therapy system.
[0085] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the invention without departing from the principles and spirit of the invention, and all such changes should fall within the protection scope of the claims of the present invention.
Claims
1. A particle accelerator beam calibration system, characterized in that, include: A bracket assembly (1) is used for mounting on a recessed surface and for providing driving force; The particle accelerator (2) is provided with a rotation axis and a beam outlet for ejecting a beam. The particle accelerator (2) is directly or indirectly connected to the support assembly (1) and suspended relative to the pit on the ground. Under the driving force of the support assembly (1), it can rotate around the rotation axis. A calibration component (3) is installed on the particle accelerator (2) and can rotate with the particle accelerator (2). It is used to perform particle accelerator beam calibration before the particle accelerator (2) leaves the factory. The calibration component (3) is provided with a through extension channel (321) that runs from front to back. The straight line of the extension channel (321) does not intersect with the rotation axis. One end of the calibration component (3) can extend horizontally to the isocenter point of the calibration system and form an indicator (323). The other end is directly or indirectly connected to the beam outlet to guide the beam leaving the particle accelerator (2) to move along the extension channel (321). The indicator (323) is used to indicate the isocenter point position of the particle accelerator (2) during the rotation of the particle accelerator (2). The indicator (323) is provided with multiple marker points (P). When the particle accelerator (2) rotates, the intersection point formed by the projection of multiple marker points (P) indicates the isocenter point position of the particle accelerator. The particle accelerator (2) is located above the pit, and the pit is connected to the space above the ground to form the rotation space of the calibration component (3); the beam calibration system is used to pre-calibrate the particle accelerator (2), and the calibration component (3) indicates the calibration of the particle accelerator (2) by the position of the isocenter point and the position offset of the path of the beam from the particle accelerator (2), and the calibrated particle accelerator (2) is moved to the proton therapy system.
2. The particle accelerator beam calibration system according to claim 1, characterized in that, The calibration assembly (3) includes a mounting base (31) and an extension rod (32) connected to each other. The mounting base (31) is mounted on the particle accelerator (2), and the indicator part (323) is provided at one end of the extension rod (32).
3. The particle accelerator beam calibration system according to claim 2, characterized in that, The extension rod (32) also includes a rod body (322), and the indicator (323) is mounted on the rod body (322) and can be locked with the rod body (322) in multiple positions; And / or, the calibration system further includes a cylinder (4) connected to the particle accelerator (2) and rotatably mounted on the support assembly (1) so that the particle accelerator (2) can rotate relative to the support assembly (1) via the cylinder (4).
4. The particle accelerator beam calibration system according to claim 1, characterized in that, The indicator (323) includes multiple indicator surfaces (3231), each of which is provided with a marker point (P). The multiple marker points (P) are projected onto the isocenter point corresponding to the particle accelerator (2) to indicate the position of the isocenter point corresponding to the particle accelerator (2).
5. The particle accelerator beam calibration system according to claim 4, characterized in that, The indicator surface (3231) is provided with crosshair lines, and the intersection of the crosshair lines forms the mark point (P); The calibration system also includes a laser lamp for generating a cross laser. The laser lamp is configured to correspond to the indicator surface (3231), and the cross laser of the laser lamp can coincide with the cross scale line of the indicator surface (3231).
6. The particle accelerator beam calibration system according to claim 5, characterized in that, It also includes a wall, to which the laser light is adjustablely mounted; The particle accelerator (2) is provided with a central marker line, and at least one of the laser lamps generates a cross laser beam that coincides with the central marker line.
7. A method for calibrating a particle accelerator beam, characterized in that, The calibration method, applied to the particle accelerator beam calibration system as described in any one of claims 1 to 6, comprises: The particle accelerator (2) is mounted on the support assembly (1) and the particle accelerator (2) is rotated to the initial position; Install the calibration component (3) and adjust its position so that the indicator (323) of the calibration component (3) can indicate the position of the isocenter point corresponding to the particle accelerator (2); Rotate the particle accelerator (2) and make the particle accelerator (2) emit beams at multiple angles, and determine the offset of the beam at multiple rotation angles by the positional deviation of the beam from the isocenter point indicated by the indicator (323); Adjust the particle accelerator (2) to correct the exit path of the beam generated by the particle accelerator (2).
8. The particle accelerator beam calibration method according to claim 7, characterized in that, The steps of mounting the particle accelerator (2) on the support assembly (1) and rotating the particle accelerator (2) to the initial position specifically include: mounting the particle accelerator (2) on the cylinder (4) and rotating the cylinder (4) to the support assembly (1), and rotating the cylinder (4) to rotate the particle accelerator (2) to the horizontal direction.
9. The particle accelerator beam calibration method according to claim 7, characterized in that, The installation of the calibration component (3) and the adjustment of its position specifically include: A first laser lamp (51) is installed facing the exit port of the particle accelerator (2), and a second laser lamp (52) is installed on both sides of the particle accelerator (2). Install the calibration component (3) and adjust the position of the indicator (323) of the calibration component (3) according to the laser generated by the first laser lamp (51); Adjust the position of the second laser lamp (52) so that the laser generated by the second laser lamp (52) corresponds to the indicator (323).
10. The particle accelerator beam calibration method according to claim 9, characterized in that, The installation of the first laser lamp (51) facing the beam outlet of the particle accelerator (2) specifically includes: installing the first laser lamp (51) at the position where the beam generated by the particle accelerator (2) irradiates the wall, and making the laser generated by the first laser lamp (51) coincide with the center mark line of the particle accelerator (2); The installation of the calibration component (3) and the position adjustment of the indicator (323) of the calibration component (3) according to the laser generated by the first laser lamp (51) specifically includes: adjusting the position between the indicator surface (3231) of the indicator (323) facing the first laser lamp (51) and the first laser lamp (51) so that the crosshair of the indicator surface (3231) facing the first laser lamp (51) coincides with the laser generated by the first laser lamp (51), and locking the calibration component (3).
11. The particle accelerator beam calibration method according to claim 8, characterized in that, The adjustment of the particle accelerator (2) to calibrate the exit path of the beam generated by the particle accelerator (2) specifically includes: Determine whether the offset of the beam in the first direction at each rotation angle exceeds a threshold. If the offset of the beam in the first direction exceeds the threshold, adjust the path of the beam in the first direction. The offset of the beam in the second direction at multiple rotation angles is obtained, and the particle accelerator (2) is adjusted according to the offset of the beam in the second direction at multiple rotation angles. The first direction is parallel to the axis of rotation, and the first direction and the second direction are perpendicular to each other.
12. The particle accelerator beam calibration method according to claim 11, characterized in that, The adjustment of the particle accelerator (2) according to the offset of the beam in the second direction at multiple rotation angles specifically includes: Calculate the deflection angle β of the particle accelerator (2), where the deflection angle β = arctan a / b, a is the average of the maximum and minimum values of the multiple offsets of the beam in the second direction, and b is the source axis distance of the particles in the particle accelerator (2). The relative position of the particle accelerator (2) and the cylinder (4) is adjusted according to the deflection angle β of the particle accelerator (2).