HIGH-SPEED ENERGY SWITCHING

• US 20170182338A1
• Filed: 01/05/2017
• Published: 06/29/2017
• Est. Priority Date: 12/20/2013
• Status: Active Grant

• Current Assignee: Mevion Medical Systems Incorporated
• Original Assignee: Mevion Medical Systems Incorporated
• Inventors: Zwart, Gerrit Townsend, Jones, Mark R., Cooley, James, Molzahn, Adam
• Granted Patent: US 10,675,487 B2
• Time in Patent Office: Days
• CPC Class Codes: A61N 2005/1087 Ions; Protons
• CPC Class Codes: A61N 2005/1095 Elements inserted into the radiation path within the system, e.g. filters or wedges
• CPC Class Codes: A61N 5/1042 with spatial modulation of the radiation beam within the treatment head
• CPC Class Codes: A61N 5/1043 Scanning the radiation beam, e.g. spot scanning or raster scanning
• CPC Class Codes: A61N 5/1045 using a multi-leaf collimator, e.g. for intensity modulated radiation therapy or IMRT
• CPC Class Codes: A61N 5/1048 Monitoring, verifying, controlling systems and methods
• CPC Class Codes: A61N 5/1077 Beam delivery systems
• CPC Class Codes: A61N 5/1081 Rotating beam systems with a specific mechanical construction, e.g. gantries
• CPC Class Codes: A61N 5/1083 Robot arm beam systems
• CPC Class Codes: G21K 1/046 varying the contour of the field, e.g. multileaf collimators
• CPC Class Codes: G21K 1/10 Scattering devices; Absorbing devices; Ionising radiation filters
• CPC Class Codes: H05H 13/02 Synchrocyclotrons, i.e. frequency modulated cyclotrons
• CPC Class Codes: H05H 2007/002 for modifying beam trajectory, e.g. gantries
• CPC Class Codes: H05H 2007/004 for modifying beam energy, e.g. spread out Bragg peak devices
• CPC Class Codes: H05H 2007/007 for focusing the beam to irradiation target
• CPC Class Codes: H05H 2007/046 for beam deflection
• CPC Class Codes: H05H 2007/122 by electromagnetic means, e.g. RF cavities
• CPC Class Codes: H05H 7/001 Arrangements for beam delivery or irradiation irradiation systems per se G21K5/00
• CPC Class Codes: H05H 7/04 Magnet systems , e.g. undulators, wigglers free-electron laser H01S3/0903; Energisation thereof

Abstract

An example particle therapy system may include: a synchrocyclotron to produce a particle beam; a scanner to move the particle beam in one or more dimensions relative to an irradiation target; and an energy degrader that is between the scanner and the irradiation target. The energy degrader may include multiple plates that are movable relative to a path of the particle beam, with the multiple plates each being controllable to move while in the path of the particle beam and during movement of the particle beam. An aperture may be between the energy degrader and the irradiation target. The aperture being may be to trim the particle beam prior to the particle beam reaching the irradiation target.

Claims

1. A particle therapy system comprising:

a particle accelerator to output a particle beam; and

an energy degrader that is controllable to pass the particle beam to an irradiation target, at least part of the energy degrader being controllable to move during passage of the particle beam to the irradiation target.

2. The particle therapy system of claim 1, wherein the energy degrader comprises plates that are movable.

3. The particle therapy system of claim 1, wherein the energy degrader comprises multiple plates;

and

wherein the multiple plates comprise a first plate and a second plate that are controllable to move during passage of the particle beam.

4. The particle therapy system of claim 3, wherein the second plate is controllable to trail the first plate during movement, or the first plate is controllable to trail the second plate during movement.

5. The particle therapy system of claim 3, further comprising:

a scanner that is controllable to move the particle beam in one or more dimensions relative to the irradiation target;

wherein at least one of the energy degrader or the scanner is controllable so that, during movement of the first plate and the second plate, the particle beam passes through the first plate but not the second plate or the second plate but not the first plate.

6. The particle therapy system of claim 3, further comprising:

a scanner that is controllable to move the particle beam in one or more dimensions relative to the irradiation target;

wherein at least one of the energy degrader or the scanner is controllable so that, during movement of the first plate and the second plate, the particle beam passes through both first plate and the second plate.

7. The particle therapy system of claim 3, further comprising:

a scanner that is controllable to move the particle beam in one or more dimensions relative to the irradiation target;

wherein movement of the particle beam across a plate among the multiple plates is limited to movement outside of a predefined distance from an edge of the plate.

8. The particle therapy system of claim 1, wherein the energy degrader comprises multiple plates, the multiple plates comprising a first plate and a second plate that are controllable to move during passage of the particle beam;

wherein, during movement of the first plate and the second plate, the first plate and the second plate move from a starting position to an ending position; and

wherein the particle beam is controllable to move from a location towards the ending position such that the particle beam passes through both the first plate and the second plate or through only one of the first plate or the second plate.

9. The particle therapy system of claim 1, wherein the energy degrader comprises multiple plates, the multiple plates comprising a first plate and a second plate that are controllable to move during passage of the particle beam;

wherein, during movement of the first plate and the second plate, the first plate and the second plate move from a starting position to an ending position; and

wherein the particle beam is controllable to move from a location towards the starting position such that the particle beam passes through both the first plate and the second plate or through only one of the first plate or the second plate.

10. The particle therapy system of claim 1, wherein the energy degrader comprises multiple plates;

and

wherein the multiple plates comprise one or more first plates and one or more second plates, the one or more first plates and the one or more second plates being controllable to move relative to the particle beam, each of one or more first plates having a thickness that is less than thicknesses of the one or more second plates.

11. The particle therapy system of claim 10, wherein a first plate among the one or more first plates has a thickness that is a fraction of a thickness of each of the one or more second plates.

12. The particle therapy system of claim 11, wherein the first plate has a thickness that is half of a thickness of each of the one or more second plates.

13. The particle therapy system of claim 1, wherein the energy degrader comprises multiple plates;

and

wherein control over movement of the multiple plates comprises sequencing movement of the multiple plates so that each of multiple layers of the irradiation target is subjected to the particle beam.

14. The particle therapy system of claim 13, wherein control over movement of the multiple plates comprises sequencing movement of the multiple plates so that the multiple layers of the irradiation target are treated with the particle beam non-sequentially.

15. The particle therapy system of claim 1, wherein the energy degrader comprises multiple plates;

and

wherein control over movement of the multiple plates comprises sequencing movement of the multiple plates so that an energy of the particle beam corresponds to a location of each of multiple layers of the irradiation target.

16. The particle therapy system of claim 1, further comprising:

an aperture that is controllable to trim spots of the particle beam, the aperture being between the irradiation target and the energy degrader.

17. The particle therapy system of claim 1, wherein the energy degrader comprises one or more plates that are movable relative to the irradiation target during passage of the particle beam;

and

wherein each of the one or more plates has a size that is less than a size of a radiation field.

18. A particle therapy system comprising:

a synchrocyclotron to produce a particle beam;

a scanner to move the particle beam in one or more dimensions relative to an irradiation target;

an energy degrader that is between the scanner and the irradiation target, the energy degrader comprising multiple plates that are movable relative to a path of the particle beam, the multiple plates each being controllable to move while in the path of the particle beam and during movement of the particle beam; and

an aperture between the energy degrader and the irradiation target, the aperture being controllable to trim the particle beam prior to the particle beam reaching the irradiation target.

19. The particle therapy system of claim 18, further comprising:

an outer gantry on which the synchrocyclotron is mounted, the outer gantry being configured to move the synchrocyclotron at least partly around the irradiation target; and

an inner gantry, within a sweep of the outer gantry, the inner gantry comprising a nozzle on which the energy degrader is mounted, the inner gantry being configured to move the energy degrader based on movement of the outer gantry.

20. The particle therapy system of claim 18, wherein the multiple plates comprise a first plate and a second plate that are controllable to move in a first direction and a second direction during passage of the particle beam, the first direction being from a starting position to an ending position, and the second direction being from the ending position to the starting position;

wherein at least one of the scanner or the energy degrader is controllable so that, during movement of the first plate and the second plate in the first direction, the particle beam passes through either the first plate only or the second plate only or through both the first plate and the second plate; and

wherein at least one of the scanner or the energy degrader is controllable so that, during movement of the first plate and the second plate in the second direction, the particle beam passes through either the first plate only or the second plate only or through both the first plate and the second plate.

21. The particle therapy system of claim 18, wherein the multiple plates comprise a first plate and a second plate, the first plate and the second plate being controllable to move separately during application of the particle beam.

22. The particle therapy system of claim 21, wherein the second plate is controllable to trail the first plate during movement, or the first plate is controllable to trail the second plate during movement.

23. The particle therapy system of claim 21, wherein at least one of the energy degrader or the scanner is controllable so that movement of the particle beam during movement of the first plate and the second plate is such that the particle beam passes through the first plate but not the second plate or through the second plate but not the first plate.

24. The particle therapy system of claim 21, wherein at least one of the energy degrader or the scanner is controllable so that movement of the particle beam during movement of the first plate and the second plate is such that the particle beam passes through both the first plate and the second plate.

25. The particle therapy system of claim 18, wherein movement of the particle beam across a plate among the multiple plates is limited to movement outside of a distance from an edge of the plate.

26. The particle therapy system of claim 18, wherein the multiple plates comprise a first plate and a second plate that are controllable to move;

wherein, during movement of the first plate and the second plate, the first plate and the second plate move from a starting position to an ending position; and

wherein the scanner is controllable to move the particle beam from a location towards the ending position such that the particle beam passes through both the first plate and the second plate or through only one of the first plate or the second plate.

27. The particle therapy system of claim 18, wherein multiple plates comprise a first plate and a second plate that are controllable to move;

wherein, during movement of the first plate and the second plate, the first plate and the second plate move from a starting position to an ending position; and

wherein the scanner is controllable to move the particle beam from a location towards the starting position such that the particle beam passes through both the first plate and the second plate or through only one of the first plate or the second plate.

28. The particle therapy system of claim 18, wherein the multiple plates comprise one or more first plates and one or more second plates, the one or more first plates and one or more second plates being controllable to move during application of the particle beam, each of the one or more first plates having a thickness that is less than thicknesses of the one or more second plates.

29. The particle therapy system of claim 18, wherein each of the multiple plates has a size that is less than a size of a radiation field.

30. A particle therapy system to apply a particle beam to an irradiation target, the particle therapy system comprising:

a scanner to move the particle beam in one or more dimensions relative to the irradiation target; and

an energy degrader comprising elements that are controllable to move during movement of the particle beam, the energy degrader for passing the particle beam prior to application of the particle beam to the irradiation target.

31. The particle therapy system of claim 30, wherein the elements comprise plates that are controllable to move in a sequence to change an energy of the particle beam so that different layers of the irradiation target are subjected to the particle beam.

32. The particle therapy system of claim 30, wherein the elements comprise a first plate and a second plate, both the first plate and the second plate being controllable to move during movement of the particle beam;

and

wherein at least one of the energy degrader or the scanner is controllable so that the particle beam passes through the first plate but not the second plate or through the second plate but not the first plate during at least part of the movement of the first plate and the second plate.

33. The particle therapy system of claim 30, wherein the elements comprise a first plate and a second plate, both the first plate and the second plate being controllable to move during movement of the particle beam;

and

wherein at least one of the energy degrader or the scanner is controllable so that the particle beam passes through both the first plate and the second plate during at least part of the movement of the first plate and the second plate.

34. The particle therapy system of claim 30, wherein at least one of the energy degrader or the scanner is controllable so that the particle beam does not pass within at least a distance from an edge of at least one of the elements, the distance being based on a distribution of particles in a spot representing a cross-section of the particle beam at the at least one of the elements.

35. The particle therapy system of claim 30, wherein the elements are controllable to move in at least one of a first direction or a second direction during movement of the particle beam, the first direction being from a starting position of the elements to an ending position of the elements, and the second direction being from the ending position to the starting position.

36. The particle therapy system of claim 30, wherein at least some of the elements are controllable to move separately during movement of the particle beam.

37. The particle therapy system of claim 30, wherein at least some of the elements are controllable to move together during movement of the particle beam.

38. The particle therapy system of claim 30, wherein each of the multiple elements has a size that is less than a size of a radiation field.