Collimator and energy degrader

Abstract

A particle therapy system includes a particle accelerator to output a particle beam; and a scanning system for the particle accelerator to scan the particle beam across at least part of an irradiation target. The scanning system is configured to scan the particle beam in two dimensions that are at an angle relative to a direction of the particle beam. A structure defines an edge. The structure is controllable to move in the two dimensions relative to the irradiation target such that at least part of the structure is between at least part of the particle beam and the irradiation target. The structure includes a material that inhibits transmission of the particle beam.

What is claimed is: 
     
         1 - 42 . (canceled) 
     
     
         43 . A particle therapy system comprising:
 a particle accelerator to output a particle beam;   one or more scanning magnets that are down-beam of the particle accelerator, the one or more scanning magnets for moving the particle beam relative to at least part of an irradiation target in a patient;   an energy degrader that is down-beam of the one or more scanning magnets, the energy degrader comprising a material that allows the particle beam to pass through and thereby reduce an energy of the particle beam, the energy degrader being configurable during movement of the particle beam; and   a collimator that is down-beam of the one or more scanning magnets, the collimator being controllable to change a shape of an edge of the collimator, at least a portion of the collimator being movable between a first part of the particle beam and the patient so that the at least a portion of the collimator blocks the first part of the particle beam from reaching the patient and so that the edge at least partly collimates a second part of the particle beam that reaches the irradiation target in the patient.   
     
     
         44 . The particle therapy system of claim  42 , wherein the least a portion of the collimator is movable based on movement of the particle beam. 
     
     
         45 . The particle therapy system of claim  42 , wherein the collimator comprises multiple parts that are adjustable to vary the shape of the edge. 
     
     
         46 . The particle therapy system of  claim 45 , wherein the multiple parts comprise fingers that are individually movable relative to the irradiation target. 
     
     
         47 . The particle therapy system of claim  42 , wherein the collimator is a first collimator, and the edge is a first edge; and
 wherein the particle therapy system comprises a second collimator that is configurable to define a shape of a second edge of the second collimator, at least a portion of the second collimator being movable between a third part of the particle beam and the patient so that the at least a portion of the second collimator blocks the third part of the particle beam from reaching the patient and so that the second edge at least partly collimates a fourth part of the beam that reaches the irradiation target in the patient.   
     
     
         48 . The particle therapy system of claim  42 , wherein the one or more scanning magnets are controllable to scan the particle beam more quickly for interior sections of the irradiation target than at edges of the irradiation target. 
     
     
         49 . The particle therapy system of claim  42 , wherein the one or more scanning magnets are controllable to scan the particle beam from different incident angles; and
 wherein the at least a portion of the collimator is controllable to move based on movement of the particle beam as the particle beam is scanned from different incident angles.   
     
     
         50 . The particle therapy system of claim  42 , wherein the collimator defines at least part of an aperture, and wherein the edge comprises an edge of the aperture. 
     
     
         51 . The particle therapy system of claim  42 , wherein the particle accelerator comprises a synchrocyclotron comprising:
 a voltage source to provide a radio frequency (RF) voltage to a cavity to accelerate particles from a plasma column, the cavity having a magnetic field causing particles accelerated from the plasma column to move orbitally within the cavity;   an extraction channel to receive the particles accelerated from the plasma column and to output the received particles from the cavity; and   a regenerator to provide a magnetic field bump within the cavity to thereby change successive orbits of the particles accelerated from the plasma column so that, eventually, particles output to the extraction channel;   wherein the magnetic field is between 4 Tesla (T) and 20 T.   
     
     
         52 . The particle therapy system of  claim 51 , further comprising:
 a gantry on which at least the particle accelerator is mounted, the gantry being configured to move the particle accelerator at least part-way around the patient.   
     
     
         53 . The particle therapy system of claim  42 , wherein the energy degrader comprises multiple pieces, each piece of the multiple pieces being comprised of beam-energy absorbing material, the energy degrader being configurable to selectively move one or more pieces of the multiple pieces into a path of the particle beam; and
 wherein the particle therapy system further comprises:
 one or more processing devices that are programmed to receive an indication of an energy of the particle beam to apply to the irradiation target, and to control selective movement of the one or more of the multiple pieces into the path of the particle beam so that a resulting energy of the particle beam approximates the energy of the particle beam to apply to the irradiation target. 
   
     
     
         54 . The particle therapy system of  claim 53 , wherein each of the multiple pieces comprises a plate. 
     
     
         55 . The particle therapy system of claim  42 , wherein the particle beam is movable within an area defined by a plane that has an area; and
 wherein each of the multiple pieces has an area that is less than the area of the plane.   
     
     
         56 . The particle therapy system of  claim 53 , further comprising:
 one or more processing devices to receive information about a scanning pattern for the irradiation target, the scanning pattern defining movement of the particle beam in at least two dimensions and movement of the one or more pieces of the energy degrader so that the one or more pieces of the energy degrader at least partly track movement of the particle beam during movement of the particle beam.   
     
     
         57 . The particle therapy system of  claim 56 , wherein the information is usable to configure the collimator to define the shape of the edge of the collimator; and
 wherein the one or more processing devices are programmed to use the information to configure the collimator.   
     
     
         58 . The particle therapy system of  claim 56 , wherein the particle accelerator is a variable-energy synchrocyclotron. 
     
     
         59 . A particle therapy system comprising:
 a particle accelerator to output a particle beam;   an energy degrader to receive the particle beam, the energy degrader comprising a beam-transmissible material that allows the particle beam to pass through the energy degrader and thereby change an energy of the beam;   a collimator comprising a material that blocks the particle beam, at least a portion of the collimator being movable into a path of a first part of the particle beam so that the at least a portion of the collimator blocks a first part of the particle beam while allowing a second part of the particle beam to pass; and   a control system to control operation of the energy degrader so that at least a portion of the energy degrader moves during movement of the particle beam, and to control operation of the collimator so that the at least a portion of the collimator moves based on the movement of the particle beam.   
     
     
         60 . The particle therapy system of  claim 59 , wherein the collimator comprises multiple parts, each of the multiple parts being controllable to move based on the movement of the particle beam. 
     
     
         61 . The particle therapy system of  claim 60 , wherein each of the multiple parts is controllable to adjust a shape of the collimator. 
     
     
         62 . The particle therapy system of  claim 60 , wherein the multiple parts comprise fingers that are individually movable into, or out of, a radiation field. 
     
     
         63 . The particle therapy system of  claim 59 , wherein the collimator is a first collimator; and
 wherein the particle therapy system comprises a second collimator, the second collimator comprising a material that blocks the particle beam, at least a portion of the second collimator being movable into a path of a third part of the particle beam so that the at least a portion of the second collimator blocks the third part of the particle beam while allowing a fourth part of the particle beam to pass.   
     
     
         64 . The particle therapy system of  claim 59 , further comprising:
 one or more scanning magnets between the particle accelerator and the energy degrader, the control system for controlling the one or more scanning magnets to scan the particle beam across a predefined field.   
     
     
         65 . The particle therapy system of  claim 59 , wherein the one or more scanning magnets are controllable to scan the particle beam from different incident angles; and
 wherein the at least a portion of the collimator is controllable to move based on movement of the particle beam as the particle beam is scanned from different incident angles.   
     
     
         66 . The particle therapy system of  claim 59 , wherein the at least a portion of the collimator defines at least part of an aperture, and wherein the at least a portion of the collimator defines an edge that comprises an edge of the aperture. 
     
     
         67 . The particle therapy system of  claim 59 , wherein the particle accelerator comprises a synchrocyclotron comprising:
 a voltage source to provide a radio frequency (RF) voltage to a cavity to accelerate particles from a plasma column, the cavity having a magnetic field causing particles accelerated from the plasma column to move orbitally within the cavity;   an extraction channel to receive the particles accelerated from the plasma column and to output the received particles from the cavity; and   a regenerator to provide a magnetic field bump within the cavity to thereby change successive orbits of the particles accelerated from the plasma column so that, eventually, particles output to the extraction channel;   wherein the magnetic field is between 4 Tesla (T) and 20 T.   
     
     
         68 . The particle therapy system of  claim 59 , further comprising:
 a gantry on which at least the particle accelerator is mounted, the gantry being configured to move the particle accelerator at least part-way around the patient.   
     
     
         69 . The particle therapy system of  claim 59 , wherein the energy degrader comprises multiple pieces, each piece of the multiple pieces being comprised of beam-transmissible material, each piece being movable into a path of the particle beam; and
 wherein the control system is configured to receive an indication of an energy of the particle beam to output, and to control movement of one or more of the multiple pieces into the path of the particle beam so that a resulting energy of the particle beam approximates the energy of the particle beam to output.   
     
     
         70 . The particle therapy system of  claim 59 , wherein each of the multiple pieces comprises a plate. 
     
     
         71 . The particle therapy system of  claim 70 , wherein the particle beam is movable within an area defined by a plane having an area; and
 wherein each of the multiple pieces has an area that is less than the area of the plane.   
     
     
         72 . The particle therapy system of  claim 59 , wherein the control system comprises:
 one or more processing devices to receive information about a scanning pattern for the irradiation target, the scanning pattern defining movement of the particle beam in at least two dimensions and movement of the energy degrader so that the energy degrader at least partly tracks movement of the particle beam during movement of the particle beam.   
     
     
         73 . The particle therapy system of  claim 72 , wherein the information is usable to configure the at least a portion of the collimator to define a shape of an edge; and
 wherein the one or more processing devices are programmed to use the information to configure the collimator.   
     
     
         74 . The particle therapy system of  claim 59 , wherein the particle accelerator is a variable-energy synchrocyclotron. 
     
     
         75 . A particle therapy system comprising:
 generating means for generating a particle beam;   scanning means for scanning the particle beam relative to an irradiation target;   degrading means for changing an energy of the particle beam being scanned, the degrading means being movable during scanning of the particle beam; and   collimating means for trimming the particle beam following changing the energy of the particle beam, the collimating means for defining all or part of an aperture through which the particle beam passes.   
     
     
         76 . The particle therapy system of  claim 75 , wherein a shape of the aperture is controllable based on scanning of the particle beam. 
     
     
         77 . A particle therapy system comprising:
 a particle accelerator to generate a particle beam;   magnets to move the particle beam relative to an irradiation target;   an energy degrader to change an energy of the particle beam being moved, at least part of the energy degrader being movable during movement of the particle beam; and   a collimator to trim the particle beam following changing the energy of the particle beam, at least part of the collimator being configurable to define all or part of an aperture through which the particle beam passes.   
     
     
         78 . The particle therapy system of  claim 77 , wherein a shape of the aperture is controllable based on scanning of the particle beam. 
     
     
         79 . A particle therapy system comprising:
 a particle accelerator to output a particle beam;   one or more scanning magnets that are down-beam of the particle accelerator, the one or more scanning magnets to move the particle beam relative to at least part of an irradiation target in a patient;   an energy degrader that is down-beam of the particle accelerator, at least part of the energy degrader to receive the particle beam, the least part of the energy degrader comprising a material that allows the particle beam to pass through the least part of the energy degrader thereby reducing an energy of the particle beam, the least part of the energy degrader being movable during movement of the particle beam; and   a configurable collimator to trim the particle beam.   
     
     
         80 . The particle therapy system of  claim 79 , wherein the energy degrader comprises multiple pieces, each piece of the multiple pieces being comprised of beam-energy absorbing material, each piece of the multiple pieces being movable into a path of the particle beam; and
 wherein the particle therapy system further comprises:
 one or more processing devices that are programmed to receive an indication of an energy of the particle beam to apply to the irradiation target, and to control movement of one or more of the multiple pieces into the path of the particle beam so that a resulting energy of the particle beam approximates the energy of the particle beam to apply to the irradiation target. 
   
     
     
         81 . The particle therapy system of  claim 79 , wherein the one or more scanning magnets are controllable to scan the particle beam from different incident angles; and
 wherein the collimator is controllable to move based on movement of the particle beam as the particle beam is scanned from different incident angles.