Beam control method for a particle radiotherapy device and beam device

Abstract

The present disclosure provides a beam control method and device for a particle radiotherapy device, the method comprising: obtaining a length of a deflection magnet, a second horizontal distance from an edge of the deflection magnet to a target region; setting, according to a treatment requirement of the particle radiotherapy device, a distance from an exit point of each particle beam to the target region, an incident angle of each particle beam, and a motion trajectory radius of each particle beam; for each particle beam, calculating an incident point position of the particle beam according to the length of the deflection magnet, the second horizontal distance, the distance from the exit point of the particle beam to the target region, the incident angle of the particle beam, and the motion trajectory radius of the particle beam; for each particle beam, calculating an exit point position of the particle beam according to the distance from the exit point of the particle beam to the target region in a magnetic field region of a focusing magnet and the incident angle of the particle beam; determining a boundary of the magnetic field region of the focusing magnet according to the incident point positions and the exit point positions of all the particle beams; and controlling the particle beams to enter the target region according to the corresponding magnetic field region configured according to the boundary.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of particle therapy, proton heavy ion radiotherapy, and in particular to a beam control method and a beam device for a particle radiotherapy device. BACKGROUND

[0002] Tumor radiotherapy, referred to as radiotherapy, is a special method for locally treating tumors using radiation effects. The rays commonly used for radiotherapy are mainly divided into two categories. The first category is to use natural alpha ions, beta electrons, gamma photons and the like generated by isotope decay for radiotherapy. The second category is to use photon beams or electron beams, proton beams, heavy particle beams and the like charged particle beams generated by accelerators for radiotherapy. In order to reduce the radiation damage to normal tissues and organs caused by charged particle beams, a method of irradiating charged particle beams from multiple directions is usually used for treatment.

[0003] In the existing beam control method, the deflection points of all particle beams in the deflection magnet are positioned at the same point, and the shape of the bunching magnet is designed on this basis. However, in fact, when deflecting high-energy particle beams with a deflection electromagnet, the reverse extension lines of the rays will not converge at a point, that is, the equivalent deflection starting point of the actual deflection of high-energy particles is not at the center of the deflection electromagnet. The effective magnetic field shape of the bunching electromagnet designed according to this scheme will not be able to make the charged particle beams accurately converge at the equivalent treatment center point.

[0004] In addition, in the existing beam control method, the magnetic field strength of the bunching magnet is constant. In this case, the large-angle deflection angle orbit and the small-angle deflection orbit of the charged particles overlap, resulting in the inability to achieve large-angle deflection of the charged particles, that is, the inability to perform omnidirectional irradiation without moving the patient. Moving the patient for omnidirectional irradiation can easily cause the problem of deformation of the tumor (target). SUMMARY

[0005] In view of the above technical problems, the present disclosure provides a beam control method and device for a particle radiotherapy device, which at least partially solves the technical problems that the existing beam control method cannot make the charged particle beams accurately converge at the equivalent treatment center point, and cannot perform omnidirectional irradiation without moving the patient.

[0006] Based on this, the first aspect of the present disclosure provides a beam control method for a particle radiation therapy device, the particle radiation therapy device comprising a deflection magnet and a focusing magnet, and a particle beam is introduced into a target region after being deflected twice by the deflection magnet and the focusing magnet, the beam control method comprising: obtaining a length of the deflection magnet, a second horizontal distance from an edge of the deflection magnet close to the focusing magnet to the target region; setting, according to a treatment requirement of the particle radiation therapy device, a distance from an exit point of each particle beam in a magnetic field region of the focusing magnet to the target region, an incident angle of each particle beam relative to the target region, and a motion trajectory radius of each particle beam in the magnetic field region of the magnet; for each particle beam, calculating a position of an incident point of the particle beam in the magnetic field region of the focusing magnet according to the length of the deflection magnet, the second horizontal distance, the distance from the exit point of the particle beam in the magnetic field region of the focusing magnet to the target region, the incident angle of the particle beam relative to the target region, and the motion trajectory radius of the particle beam in the magnetic field region of the magnet; for each particle beam, calculating a position of an exit point of the particle beam in the magnetic field region of the focusing magnet according to the distance from the exit point of the particle beam in the magnetic field region of the focusing magnet to the target region and the incident angle of the particle beam relative to the target region; determining a boundary of the magnetic field region of the focusing magnet according to a first trajectory formed by the positions of the incident points of all the particle beams and a second trajectory formed by the positions of the exit points of all the particle beams; and controlling the particle beam to be introduced into the target region according to the boundary of the corresponding magnetic field region of the focusing magnet.

[0007] According to an embodiment of the present disclosure, the beam control method further comprises: obtaining a charge amount and a momentum of charged particles of each particle beam in the beam; for each particle beam, calculating a magnetic induction intensity required for the particle beam to be deflected in the focusing magnet according to the motion trajectory radius of the particle beam in the magnetic field region of the focusing magnet and the charge amount and the momentum of the charged particles of the particle beam; and controlling the particle beams with different incident angles to be deflected in the focusing magnet without overlapping according to the magnetic induction intensities corresponding to the particle beams with different incident angles.

[0008] According to an embodiment of the present disclosure, the calculation of the position of the incident point of the particle beam in the magnetic field region of the focusing magnet according to the length of the deflection magnet, the second horizontal distance, the distance from the exit point of the particle beam in the magnetic field region of the focusing magnet to the target region, the incident angle of the particle beam relative to the target region, and the motion trajectory radius of the particle beam in the magnetic field region of the magnet specifically comprises: calculating a deflection angle of each particle beam in the deflection magnet according to the length of the deflection magnet, the second horizontal distance, the distance from the exit point of the particle beam in the magnetic field region of the focusing magnet to the target region, the incident angle of each particle beam relative to the target region, and the motion trajectory radius of each particle beam in the magnetic field region of the magnet; and for each particle beam, calculating the position of the incident point of the particle beam in the magnetic field region of the focusing magnet according to the distance from the exit point of the particle beam in the magnetic field region of the focusing magnet to the target region, the incident angle of the particle beam relative to the target region, the motion trajectory radius of the particle beam in the magnetic field region of the magnet, and the deflection angle of the particle beam in the deflection magnet.

[0009] According to embodiments of this disclosure, based on

[0010]

[0011] Calculate the deflection angle of each particle beam in the deflecting magnet, where i is the particle beam number, φ i Ri is the deflection angle of the i-th particle beam in the deflecting magnet, R1 is the distance from the exit point of each particle beam in the magnetic field region of the magnet to the target region, and Ri is the distance from the exit point of each particle beam in the magnetic field region of the magnet to the target region. i2 Let L be the radius of the trajectory of the i-th particle beam in the focusing magnet. i1 Let θ be the first horizontal distance from the deflection point of the i-th particle beam to the edge of the deflecting magnet near the focusing magnet. i Let L be the incident angle of the i-th particle beam, L2 be the second horizontal distance, L be the length of the deflecting magnet, and R be the incident angle of the i-th particle beam. i Let be the straight-line distance from the deflection center of the i-th particle in the deflecting magnet to the incident point of the focusing magnet.

[0012] According to embodiments of this disclosure, based on

[0013]

[0014] Calculate the incident point position of the particle beam, where i is the particle beam number, (x i1 y i1 Ri represents the incident point position of the i-th particle beam, R1 represents the distance from the exit point of each particle beam to the target area, and Ri represents the distance from the exit point of each particle beam to the target area. i2 Let φ be the radius of the trajectory of the i-th particle beam. i Let θ be the deflection angle of the i-th particle beam in the deflecting magnet. i Let be the incident angle of the i-th particle beam.

[0015] According to embodiments of this disclosure, based on

[0016]

[0017] Calculate the exit point position of the particle beam, where i is the particle beam number, (x i2 y i2 Let θ be the position of the exit point of the i-th particle beam, R1 be the distance from the exit point of each particle beam to the target area, and θ be the position of the exit point of the i-th particle beam. i Let be the incident angle of the i-th particle beam.

[0018] According to embodiments of this disclosure, based on

[0019]

[0020] Calculate the magnetic flux density required to deflect a particle beam at different incident angles within a focusing magnet, where i is the particle beam number, and B... ia magnetic induction strength matched for the i-th particle beam, R i2 a radius of a motion track of the i-th particle beam in the bunching magnet, P i a momentum of a charged particle of the i-th particle beam, q i a charge quantity of a charged particle of the i-th particle beam.

[0021] The second aspect of the present disclosure also provides a beam control device for a particle radiotherapy device, the particle radiotherapy device comprising a deflection magnet and a bunching magnet, and a particle beam is introduced into a target region after being deflected twice by the deflection magnet and the bunching magnet, the beam control device comprising: a first acquisition module configured to acquire a length of the deflection magnet, a second horizontal distance from an edge of the deflection magnet close to the bunching magnet to the target region; a setting module configured to set, according to a treatment requirement of the particle radiotherapy device, a distance from an exit point of each particle beam in a magnetic field region of the bunching magnet to the target region, an incident angle of each particle beam relative to the target region, and a radius of a motion track of each particle beam in the magnetic field region of the bunching magnet; a first calculation module configured to, for each particle beam, calculate a position of an incident point of the particle beam in the magnetic field region of the bunching magnet according to the length of the deflection magnet, the second horizontal distance, the distance from the exit point of the particle beam in the magnetic field region of the bunching magnet to the target region, the incident angle of the particle beam relative to the target region, and the radius of the motion track of the particle beam in the magnetic field region of the bunching magnet; a second calculation module configured to, for each particle beam, calculate a position of an exit point of the particle beam in the magnetic field region of the bunching magnet according to the distance from the exit point of the particle beam in the magnetic field region of the bunching magnet to the target region and the incident angle of the particle beam relative to the target region; a determination module configured to determine a boundary of the magnetic field region of the bunching magnet according to a first track formed by the incident point positions of all the particle beams and a first track formed by the exit point positions of all the particle beams; and a first control module configured to control the particle beams to be introduced into the target region according to the boundary of the corresponding magnetic field region.

[0022] According to an embodiment of the present disclosure, the beam control device further comprises: a second acquisition module configured to acquire a charge quantity and a momentum of a charged particle of each particle beam in the beam; a third calculation module configured to, for each particle beam, calculate a magnetic induction strength required for the particle beam to be deflected in the bunching magnet according to the radius of the motion track of the particle beam in the magnetic field region of the bunching magnet and the charge quantity and the momentum of the charged particle of the particle beam; and a second control module configured to control the particle beams with different incident angles to have non-overlapping deflection tracks in the bunching magnet according to the magnetic induction strengths corresponding to the particle beams with different incident angles. BRIEF DESCRIPTION OF DRAWINGS

[0023] The above and other objects, features and advantages of the present disclosure will become more apparent from the following description of embodiments of the present disclosure taken in conjunction with the accompanying drawings, in which:

[0024] Figure 1A structural diagram of a particle radiotherapy device is shown schematically.

[0025] Figure 2 A beam control method for a particle radiotherapy device is shown schematically.

[0026] Figure 3 A specific flowchart of operation S203 is shown schematically.

[0027] Figure 4 A charged particle motion trajectory in a deflection magnet is shown schematically.

[0028] Figure 5 A charged particle deflection trajectory in a particle beam therapy device is shown schematically.

[0029] Figure 6 A beam control method for a particle radiotherapy device is shown schematically.

[0030] Figure 7 A block diagram of a beam control device for a particle radiotherapy device is shown schematically.

[0031] Figure 8 A block diagram of a beam control device for a particle radiotherapy device is shown schematically. DETAILED DESCRIPTION

[0032] To make the objects, technical solutions and advantages of the present disclosure clearer, further detailed description will be made to the present disclosure with reference to the embodiments and the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without any creative work fall within the protection scope of the present disclosure.

[0033] The terms used herein are only used to describe specific embodiments, and are not intended to limit the present disclosure. The terms "comprise", "contain" and the like used herein indicate the existence of the described features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0034] In the present disclosure, unless specifically defined otherwise and limited in the specification, the terms "mount", "connect", "connection", "fixed", and the like, should be construed broadly and interchangeably to include fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections, or communication connections; direct connections, or indirect connections via intermediate media; internal connections between elements, or interaction between external elements. The above terms should be understood by those skilled in the art according to the specific context in which they are used in the present disclosure.

[0035] In the description of the present disclosure, it should be understood that the terms "longitudinal", "length", "circumferential", "front", "back", "left", "right", "top", "bottom", "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the subsystems or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present disclosure.

[0036] Throughout the drawings, the same elements are denoted by the same or similar reference numerals. When it may cause confusion in understanding the present disclosure, conventional structures or configurations will be omitted. Also, the shape, size, positional relationship of the components in the drawings do not reflect the true size, scale and actual positional relationship. In addition, in the claims, any reference symbols located between parentheses should not be construed as a limitation of the claims.

[0037] Similarly, in order to simplify the present disclosure and help understand one or more of the various disclosed aspects, in the above description of the exemplary embodiments of the present disclosure, various features of the present disclosure are sometimes grouped together in a single embodiment, figure or description thereof. The description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present disclosure. In the present description, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0038] In addition, the terms "first", "second" are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present disclosure, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0039] Figure 1 A schematic diagram of the structure of the particle radiotherapy device provided in the embodiments of this disclosure is shown.

[0040] like Figure 1 As shown, this particle radiotherapy device may include, for example, a deflecting magnet A and a focusing magnet B. After passing through the deflecting magnet A, the high-energy charged particle beam's trajectory is deflected, and after passing through a straight track, it enters the focusing magnet B. After the trajectory is deflected again, the charged particle beam is introduced to the center of the tumor target area (treatment center point). By designing the magnetic field boundary of the focusing magnet B and controlling the magnitude of the magnetic field strength of the deflecting magnet A and the magnetic induction of the focusing magnet B, the deflection angle φ of the charged particle beam can be controlled. i The value of θ is used to control the illumination angle. i This enables radiotherapy that utilizes a charged particle beam to irradiate the target area from all angles.

[0041] Figure 2 The schematic diagram illustrates a flow chart of a beam control method for a particle radiotherapy device provided in an embodiment of the present disclosure.

[0042] like Figure 2 As shown, the beam control method for a particle radiotherapy device may include, for example, operations S201 to S205.

[0043] In operation S201, the length of the deflecting magnet and the second horizontal distance from the edge of the deflecting magnet near the focusing magnet to the target area are obtained.

[0044] In operation S202, the distance from the exit point of each particle beam in the magnetic field region of the focusing magnet to the target area, the incident angle of each particle beam relative to the target area, and the radius of the trajectory of each particle beam in the magnetic field region of the magnet are set according to the treatment requirements of the particle radiotherapy device.

[0045] In operation S203, for each particle beam, the position of the incident point of the particle beam in the magnetic field region of the focusing magnet is calculated based on the length of the deflecting magnet, the second horizontal distance, the distance from the exit point of the particle beam in the magnetic field region of the focusing magnet to the target area, the incident angle of the particle beam relative to the target area, and the radius of the trajectory of the particle beam in the magnetic field region of the magnet.

[0046] In operation S204, for each particle beam, the position of the exit point of the particle beam in the magnetic field region of the focusing magnet is calculated based on the distance from the exit point of the particle beam in the magnetic field region of the focusing magnet to the target region and the incident angle of the particle beam relative to the target region.

[0047] In operation S205, the boundary of the focusing magnet magnetic field region is determined based on the first trajectory formed by the positions of all particle beam incident points and the second trajectory formed by the positions of all particle beam exit points. The corresponding focusing magnet magnetic field region is configured according to the boundary to control the introduction of the particle beam into the target area.

[0048] The beam flow control method for the particle beam therapy device according to the embodiments of the present disclosure obtains the actual physical parameters of the deflection magnet and the bunching magnet, sets the incident angle, the motion trajectory radius and the distance from the exit point to the center of the target area of each particle beam according to the treatment requirement, determines the boundary of the magnetic field region of the bunching magnet according to the incident point position and the exit point position of each particle beam in the magnetic field region of the bunching magnet calculated based on the parameters, and corrects the error caused by setting the magnetic field boundary by equating the deflection points of all particle beams to the same deflection point. Therefore, the control precision of the particle radiation therapy device is improved, and the treatment effect is improved.

[0049] Figure 3 A specific flowchart of operation S203 provided by the embodiments of the present disclosure is schematically shown.

[0050] As shown in Figure 3 , operation S203 may include operation S301 and operation S302.

[0051] In operation S301, the deflection angle of each particle beam in the deflection magnet is calculated according to the length of the deflection magnet, the second horizontal distance, the distance from the exit point of each particle beam in the magnetic field region of the bunching magnet to the target area, the incident angle of each particle beam relative to the target area, and the motion trajectory radius of each particle beam in the magnetic field region of the magnet.

[0052] In operation S302, for each particle beam, the incident point position of the particle beam in the magnetic field region of the bunching magnet is calculated according to the distance from the exit point of the particle beam in the magnetic field region of the bunching magnet to the target area, the incident angle of the particle beam relative to the target area, the motion trajectory radius of the particle beam in the magnetic field region of the magnet, and the deflection angle of the particle beam in the deflection magnet.

[0053] The principle of three-dimensional execution of the beam flow control method of the embodiments of the present disclosure is further introduced as follows.

[0054] Figure 4 A motion trajectory diagram of the charged particle in the deflection magnet provided by the embodiments of the present disclosure is schematically shown.

[0055] As shown in Figure 4 , when the deflection magnet A deflects the high-energy particle rays, the first horizontal distance from the deflection point Q i of the particle beam corresponding to different deflection angles to the edge of the deflection magnet is different. i The first horizontal distance L i from the deflection point Q i1 of the particle beam corresponding to different deflection angles to the edge of the deflection magnet changes with the deflection angle φ i , and the relationship satisfies:

[0056]

[0057] wherein i represents the number of the particle beam with different deflection angle, φ i is the deflection angle of the i-th particle beam, and L is the length of the deflection magnet.

[0058] Figure 5 A deflection trajectory of a charged particle in a particle beam therapy device is schematically shown.

[0059] As shown in Figure 5 , the particle beams are transported to the deflection magnet A, deflected by the deflection magnet A, and reach the focusing magnet B along different paths. The particle beams are deflected by the focusing magnet B and can be incident on the isocenter O, i.e. the equivalent patient target region, in different directions. The high-energy charged particle beams reach the P1 point, enter the uniform magnetic field region of the focusing magnet B, are deflected by the Lorentz force, and are emitted from the P2 point. The trajectories of the P1 and P2 points corresponding to the particle beams incident at different angles are the boundaries of the effective magnetic field on the left and inside of the focusing magnet B, respectively. The boundary of the effective magnetic field on the right of the focusing magnet B can accommodate the rightmost charged ion beam trajectory, and no special requirements are made on the shape. Based on this, the deflection angle of each particle beam in the deflection magnet can be calculated according to

[0060]

[0061] The deflection angle of each particle beam in the deflection magnet is calculated, wherein i is the number of the particle beam, φ i is the deflection angle of the i-th particle beam in the deflection magnet, R1 is the distance from the exit point of each particle beam in the magnetic field region of the magnet to the target region, i.e. the distance from the exit point of each particle beam to the target region is the same, R i2 is the trajectory radius of the i-th particle beam in the focusing magnet, L i1 is the first horizontal distance from the deflection point of the i-th particle beam to the edge of the deflection magnet close to the focusing magnet, θ i is the incidence angle of the i-th particle beam, L2 is the second horizontal distance, L is the length of the deflection magnet, R i is the straight-line distance from the deflection center of the i-th particle in the deflection magnet to the incident point of the focusing magnet

[0062] The incident point position of the particle beam is calculated according to

[0063]

[0064] The incident point position of the particle beam is calculated according to i1 , y i1 is the incident point position of the i-th particle beam, R1 is the distance from the exit point of each particle beam to the target region, R i2 is the trajectory radius of the i-th particle beam, φ iθ i is the deflection angle of the i th particle beam i θ i is the deflection angle of the i th particle beam

[0065] According to the above calculation process, the positions of the incident point P1 and the exit point P2 corresponding to the particle beams with different deflection angles can be obtained, and the trajectory based on the positions of the incident point P1 and the exit point P2 can be used to determine the boundary of the effective magnetic field of the focusing magnet, and based on the determined boundary of the effective magnetic field, the accurate control of different particle beams can be realized.

[0066]

[0067] The incident point position of the particle beam is calculated, where i is the number of the particle beam, (x i, y i ) is the exit point position of the i th particle beam, and R1 is the distance from the exit point of each particle beam to the target region. i2 i2 i θ i is the deflection angle of the i th particle beam

[0068] Based on the above calculation process, the positions of the incident point P1 and the exit point P2 corresponding to the particle beams with different deflection angles can be obtained, and the trajectory based on the positions of the incident point P1 and the exit point P2 can be used to determine the boundary of the effective magnetic field of the focusing magnet, and based on the determined boundary of the effective magnetic field, the accurate control of different particle beams can be realized.

[0069] Based on the above embodiment, the disclosure further provides a beam control for a particle radiation therapy device.

[0070] Figure 6 A flow chart of a beam control method for a particle radiation therapy device provided by another embodiment of the disclosure is schematically shown.

[0071] As shown in FIG. 6, the beam control method for the particle radiation therapy device may, for example, further include operation S601 to operation S603. Figure 6

[0072] In operation S601, the charge amount and momentum of the charged particles of each particle beam in the beam are obtained.

[0073] In operation S602, for each particle beam, the magnetic induction intensity required for the deflection of the particle beam in the focusing magnet is calculated according to the motion trajectory radius of the particle beam in the magnetic field region of the focusing magnet and the charge amount and momentum of the charged particles of the particle beam.

[0074] In operation S603, the deflection trajectories of the particle beams with different incident angles in the focusing magnet are controlled not to overlap according to the magnetic induction intensities corresponding to the particle beams with different incident angles.

[0075] In the embodiment of the disclosure, the magnetic induction intensity required for the deflection of the particle beam in the focusing magnet can be calculated according to the following formula:

[0076]

[0077] The magnetic induction intensity required for the deflection of the particle beam in the focusing magnet is calculated, where i is the number of the particle beam, and B i is the magnetic induction intensity required for the deflection of the i th particle beam.​​​i is a magnetic induction strength matched for the i-th particle beam, R i2 is a radius of a motion track of the i-th particle beam in the bunching magnet, P i is a momentum of a charged particle of the i-th particle beam, q i is a charge quantity of the charged particle of the i-th particle beam.

[0078] According to the embodiments of the present disclosure, on the basis of the above setting of the effective boundary magnetic field, the corresponding magnetic induction strength is further matched for the particle beams with different incident angles, so as to control the deflection tracks of the different particle beams in the bunching magnet not to overlap and not to affect each other, thereby being capable of realizing 360° omnidirectional charged particle beam irradiation treatment on the target region, reducing the movement of the patient, and further reducing the risk of target deformation caused by the movement of the patient.

[0079] Based on the same inventive concept, the embodiments of the present disclosure further provide a beam control device for a particle radiotherapy device.

[0080] Figure 7 A block diagram of the beam control device for the particle radiotherapy device provided by an embodiment of the present disclosure is schematically shown.

[0081] As Figure 7 shown, the beam control device 700 may, for example, include a first acquisition module 710, a setting module 720, a first calculation module 730, a second calculation module 740, a determination module 750, and a first control module 760.

[0082] The first acquisition module is configured to acquire a length of the deflection magnet, a second horizontal distance from an edge of the deflection magnet close to the bunching magnet to the target region.

[0083] The setting module is configured to set, according to a treatment requirement of the particle radiotherapy device, a distance from an exit point of each particle beam in a magnetic field region of the bunching magnet to the target region, an incident angle of each particle beam relative to the target region, and a radius of a motion track of each particle beam in the magnetic field region of the bunching magnet.

[0084] The first calculation module is configured to, for each particle beam, calculate a position of an incident point of the particle beam in the magnetic field region of the bunching magnet according to the length of the deflection magnet, the second horizontal distance, the distance from the exit point of the particle beam in the magnetic field region of the bunching magnet to the target region, the incident angle of the particle beam relative to the target region, and the radius of the motion track of the particle beam in the magnetic field region of the bunching magnet.

[0085] The second calculation module is configured to, for each particle beam, calculate a position of an exit point of the particle beam in the magnetic field region of the bunching magnet according to the distance from the exit point of the particle beam in the magnetic field region of the bunching magnet to the target region and the incident angle of the particle beam relative to the target region.

[0086] The determining module is configured to determine the boundary of the magnetic field region of the bunching magnet according to the first trajectory formed by all the particle beam incident point positions and the second trajectory formed by all the particle beam exit point positions.

[0087] The first control module is configured to control the particle beams to be introduced into the target region according to the corresponding magnetic field region of the bunching magnet.

[0088] Figure 8 A block diagram of a beam control device for a particle radiotherapy device is schematically shown.

[0089] As Figure 8 shown, the beam control device 700 may further include a second obtaining module 770, a third calculating module 780 and a second control module 790.

[0090] The second obtaining module is configured to obtain the charge amount and momentum of the charged particles of each particle beam in the beam.

[0091] The third calculating module is configured to, for each particle beam, calculate the magnetic induction intensity required for the deflection of the particle beam in the bunching magnet according to the motion trajectory radius of the particle beam in the magnetic field region of the bunching magnet and the charge amount and momentum of the charged particles of the particle beam.

[0092] The second control module is configured to control the particle beams with different incident angles to be deflected in the bunching magnet so as to make the deflection trajectories of the particle beams with different incident angles not overlap.

[0093] It should be noted that the beam control device for a particle radiotherapy device of the present disclosure corresponds to the beam control method for a particle radiotherapy device of the present disclosure, and the specific implementation details and the resulting technical effects are the same, which will not be described here.

[0094] The above-described specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present disclosure, and it should be understood that the above-described specific embodiments are only for the specific embodiments of the present disclosure and are not intended to limit the present disclosure. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A beam control method for a particle radiotherapy apparatus including a deflection magnet and a focusing magnet through which a particle beam is introduced into a target region after being deflected twice, characterized by, The beam control method comprises: acquiring a length of the deflection magnet, a second horizontal distance from an edge of the deflection magnet close to the bunching magnet to the target region; setting, according to a treatment requirement of the particle radiation treatment device, a distance from an exit point of each particle beam in a magnetic field region of the bunching magnet to the target region, an incident angle of each particle beam relative to the target region, and a radius of a motion track of each particle beam in the magnetic field region of the bunching magnet; for each particle beam, calculating a position of an incident point of the particle beam in the magnetic field region of the bunching magnet according to the length of the deflection magnet, the second horizontal distance, the distance from the exit point of the particle beam in the magnetic field region of the bunching magnet to the target region, the incident angle of the particle beam relative to the target region, and the radius of the motion track of the particle beam in the magnetic field region of the bunching magnet; for each particle beam, calculating a position of an exit point of the particle beam in the magnetic field region of the bunching magnet according to the distance from the exit point of the particle beam in the magnetic field region of the bunching magnet to the target region and the incident angle of the particle beam relative to the target region; determining a boundary of the magnetic field region of the bunching magnet according to a first track formed by the incident point positions of all the particle beams and a second track formed by the exit point positions of all the particle beams; and controlling the particle beams to enter the target region according to the corresponding magnetic field region of the bunching magnet configured according to the boundary.

2. The beam control method for a particle radiotherapy device according to claim 1, wherein, The beam control method further comprises: acquiring a charge amount and a momentum of charged particles of each particle beam in the beam; for each particle beam, calculating a magnetic induction intensity required for deflection of the particle beam in the bunching magnet according to the radius of the motion track of the particle beam in the magnetic field region of the bunching magnet and the charge amount and the momentum of the charged particles of the particle beam; controlling the particle beams with different incident angles to have different magnetic induction intensities so that the particle beams with different incident angles do not overlap in deflection tracks in the bunching magnet.

3. The beam control method for a particle radiotherapy device according to claim 1 or 2, characterized in that, The calculation of the position of the incident point of the particle beam in the magnetic field region of the bunching magnet according to the length of the deflection magnet, the second horizontal distance, the distance from the exit point of the particle beam in the magnetic field region of the bunching magnet to the target region, the incident angle of the particle beam relative to the target region, and the radius of the motion track of the particle beam in the magnetic field region of the bunching magnet specifically comprises: calculating a deflection angle of each particle beam in the deflection magnet according to the length of the deflection magnet, the second horizontal distance, the distance from the exit point of each particle beam in the magnetic field region of the bunching magnet to the target region, the incident angle of each particle beam relative to the target region, and the radius of the motion track of each particle beam in the magnetic field region of the bunching magnet; for each particle beam, calculating the position of the incident point of the particle beam in the magnetic field region of the bunching magnet according to the distance from the exit point of the particle beam in the magnetic field region of the bunching magnet to the target region, the incident angle of the particle beam relative to the target region, the radius of the motion track of the particle beam in the magnetic field region of the bunching magnet, and the deflection angle of the particle beam in the deflection magnet.

4. The beam control method for a particle radiotherapy device according to claim 3, wherein, According to calculating a deflection angle of each particle beam in the deflection magnet, wherein i is a number of the particle beam, and i is a deflection angle of the i-th particle beam in the deflection magnet, R1 is a distance from an exit point of each particle beam in a magnetic field region of the magnet to the target region, R i2 is a trajectory radius of the i-th particle beam in the bunching magnet, L i1 is a first horizontal distance from a deflection point of the i-th particle beam to an edge of the deflection magnet close to the bunching magnet, θ i is an incident angle of the i-th particle beam, L2 is the second horizontal distance, L is a length of the deflection magnet, R i is a straight line distance from a deflection center of the i-th particle in the deflection magnet to an incident point of the bunching magnet.

5. The beam control method for a particle radiotherapy device according to claim 3, wherein, According to calculating the incident point position of the particle beams, wherein i is the number of the particle beam, (x i1 , y i1 ) is the incident point position of the i-th particle beam, R1 is the distance from the exit point of each particle beam to the target region, R i2 is the radius of the motion trajectory of the i-th particle beam, ϕ i is the deflection angle of the i-th particle beam in the deflection magnet, and θ i is the incident angle of the i-th particle beam.

6. The beam control method for a particle radiotherapy device according to claim 3, wherein, According to calculating an exit point position of the particle beam, wherein i is a number of the particle beam, (x i2 , y i2 ) is an exit point position of the i-th particle beam, R1 is a distance from the exit point of each particle beam to the target region, θ i is an incident angle of the i-th particle beam.

7. The beam control method for a particle radiotherapy device according to claim 2, wherein, According to magnetic induction strength required for deflecting the particle beams of different incidence angles in the bunching magnet, wherein i is the number of the particle beam, B i is the matched magnetic induction strength for the i-th particle beam, R i2 is the radius of the motion trajectory of the i-th particle beam in the bunching magnet, P i is the momentum of the charged particle of the i-th particle beam, q i is the charge quantity of the charged particle of the i-th particle beam.

8. A beam control device for a particle radiotherapy device, the particle radiotherapy device comprising a deflection magnet and a focusing magnet, through which a particle beam is introduced into a target region after two deflections, characterized in that, The beam control device comprises: a first acquisition module configured to acquire a length of the deflection magnet and a second horizontal distance from an edge of the deflection magnet close to the bunching magnet to the target region; The setting module is configured to set, according to a treatment requirement of the particle radiation treatment device, a distance from an exit point of each particle beam in a magnetic field region of the bunching magnet to the target region, an incident angle of each particle beam relative to the target region, and a radius of a motion track of each particle beam in the magnetic field region of the bunching magnet; The first calculation module is configured to, for each particle beam, calculate a position of an incident point of the particle beam in the magnetic field region of the bunching magnet according to a length of the deflection magnet, the second horizontal distance, the distance from the exit point of the particle beam in the magnetic field region of the bunching magnet to the target region, the incident angle of the particle beam relative to the target region, and the radius of the motion track of the particle beam in the magnetic field region of the bunching magnet; The second calculation module is configured to, for each particle beam, calculate a position of an exit point of the particle beam in the magnetic field region of the bunching magnet according to the distance from the exit point of the particle beam in the magnetic field region of the bunching magnet to the target region and the incident angle of the particle beam relative to the target region; The determining module is configured to determine a boundary of the magnetic field region of the bunching magnet according to a first track formed by the incident point positions of all the particle beams and a second track formed by the exit point positions of all the particle beams; The first control module is configured to control the particle beams to enter the target region according to the boundary of the corresponding magnetic field region of the bunching magnet.

9. The beam control device for a particle radiotherapy device according to claim 8, characterized in that, The beam control device further comprises: The second acquisition module is configured to acquire a charge amount and a momentum of charged particles of each particle beam in the beam; The third calculation module is configured to, for each particle beam, calculate a magnetic induction intensity required for deflection of the particle beam in the bunching magnet according to the radius of the motion track of the particle beam in the magnetic field region of the bunching magnet and the charge amount and the momentum of the charged particles of the particle beam; The second control module is configured to control the particle beams with different incident angles to deflect tracks in the bunching magnet without overlapping according to the corresponding magnetic induction intensities of the particle beams with different incident angles.

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