Method and system for dynamically-trimmed spot scanning for ion therapy

Patent metadata

Field	Value
Publication number	US-9776017-B2
Application number	US-201414897077-A
Country	US
Kind code	B2
Filing date	Jul 3, 2014
Priority date	Jul 5, 2013
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

A spot scanning (SS) ion therapy system configured for dynamic trimming of an ion particle pencil beam to reduce the amount of the radiation dosage outside of a target boundary.

First claim

What is claimed is:

1. A spot scanning (SS) ion therapy system, comprising:
a. an ion therapy source comprising at least one scanning magnet, the ion therapy source configured to sequentially direct a particle pencil beam to a number of spot positions in a target;
b. a dynamic trimming collimator configured to be mounted downstream of the at least one scanning magnet of the ion therapy source, the dynamic trimming collimator comprising:
i. at least one trimmer located downstream of the at least one scanning magnet and configured to intercept a portion of said pencil beam; and
ii. at least one driving mechanism configured for moving said at least one trimmer; and

c. a controller configured to control the ion therapy source to execute the sequence of spot irradiations by sequentially directing and delivering the particle pencil beam to the number of spot positions in the target and control the position of said at least one trimmer as a function of each of said number of spot positions.

2. The spot scanning ion therapy system according to claim 1 , wherein said at least one driving mechanism is configured for moving said at least one trimmer along a first axis of motion.

3. The spot scanning ion therapy system according to claim 2 , wherein said first axis is substantially perpendicular to said pencil beam.

4. The spot scanning ion therapy system of claim 3 , wherein the at least one trimmer is further configured to move in a second axis of motion, wherein the second axis of motion is substantially parallel to said pencil beam.

5. The spot scanning ion therapy system according to claim 1 wherein said at least one driving mechanism comprises a first axis of motion and a second axis of motion for moving said at least one trimmer.

6. The spot scanning ion therapy system according to claim 5 , wherein said first axis and said second axis are substantially perpendicular to said pencil beam.

7. The spot scanning ion therapy system according to claim 5 wherein said first and second axes of motion are translation axes for translating said at least one trimmer, said translation axis are non-parallel axes.

8. The spot scanning ion therapy system according to claim 5 wherein first axis of motion is a translation axis and second axis of motion is a rotation axis.

9. The spot scanning ion therapy system according to claim 5 , wherein the said at least one trimmer is further configured to move in a third axis of motion, wherein the third axis of motion is substantially parallel to said pencil beam.

10. The spot scanning ion therapy system of claim 1 , wherein said at least one trimmer has a thickness and shape adapted to modify the phase space of said pencil beam.

11. The spot scanning ion therapy system of claim 1 , wherein said controller is further configured for receiving a signal indicating a beam on/off status information to allow motion of said at least one trimmer only when the beam is in an off status.

12. The spot scanning ion therapy system of claim 1 , wherein said controller is configured for dynamically moving said at least one trimmer in synchrony with the execution of said sequence of spot irradiations.

13. The spot scanning ion therapy system of claim 1 , further comprising a position planning controller configured for defining one or more of said spot irradiations, corresponding to pre-defined positions for positioning said at least one trimmer.

14. The spot scanning ion therapy system of claim 1 , wherein said at least one trimmer further comprises a plurality of trimmers and wherein said at least one driving mechanism comprises a plurality of driving mechanisms that correspond to the plurality of trimmers, wherein said controller is configured for independently controlling the position of each of said plurality of trimmers as a function of said spot position.

15. The spot scanning ion therapy system of claim 1 , further configured for two-dimensional delivery.

16. The spot scanning ion therapy system according to claim 1 , wherein the controller is configured to receive data defining the trimmer position for each of the number of spot positions.

17. A dynamic trimming collimator comprising:
a. at least one trimmer configured to limit spillage of radiation from a two-dimensional scanning ion beam; and
b. at least one driving mechanism configured for moving the at least one trimmer;
wherein the dynamic trimming collimator is capable of being mounted downstream an ion therapy source configured to produce the two-dimensional scanning ion beam in a sequence to a number of spot positions in a target, and wherein the dynamic trimming collimator is capable of controlling the position of said at least one trimmer to limit spillage of radiation of the two-dimensional scanning ion beam at said target as a function for each of the number of spot positions.

18. The dynamic trimming collimator of claim 17 , wherein the at least one trimmer is configured to limit spillage of radiation by partially blocking the two dimensional scanning ion beam.

19. The dynamic trimming collimator of claim 17 , wherein the at least one trimmer is configured to move along a first path substantially perpendicular to an axis of the two dimensional scanning ion beam.

20. The dynamic trimming collimator of claim 19 , wherein the at least one trimmer is further configured to move along a second path substantially parallel to the axis of the two dimensional scanning ion beam.

21. The dynamic trimming collimator of claim 20 , wherein the first axis and the second axis are non-parallel to each other.

22. The dynamic trimming collimator of claim 17 , wherein the at least one trimmer is further configured to move along a third path substantially parallel to the axis of the two dimensional scanning ion beam.

23. The dynamic trimming collimator of claim 19 , wherein the at least one driving mechanism comprises a linear motor.

24. The dynamic trimming collimator of claim 19 , wherein the at least one trimmer is configured to move in a substantially pendulous arc.

25. The dynamic trimming collimator of claim 19 , wherein the at least one trimmer comprises a rectangular shape.

26. The dynamic trimming collimator of claim 19 , wherein the at least one trimmer is configured to have a radiological thickness that is greater than the range of the two dimensional scanning ion beam.

27. The dynamic trimming collimator of claim 19 , wherein the apparatus is configured to position the at least one trimmer approximate the skin of a patient.

28. The dynamic trimming collimator of claim 19 , wherein the at least one trimmer is configured to move in synchrony with the two dimensional scanning ion beam.

29. The dynamic trimming collimator of claim 19 , wherein the at least one trimmer comprises a plurality of trimmers and the at least one driving mechanism comprises a plurality of driving mechanisms, wherein at least each of the plurality of trimmers is associated with at least one of the plurality of driving mechanisms.

30. The dynamic trimming collimator of claim 29 , wherein at least one of the plurality of trimmers is associated with at least two driving mechanisms.

31. The dynamic trimming collimator of claim 17 , further comprising a range shifter.

32. The dynamic trimming collimator of claim 17 , further comprising a ridge filt

Assignees

• Univ Iowa Res Found

Inventors

• Flynn Ryan
• Hyer Daniel
• Wang Dongxu
• HILL Patrick
• Claereboudt Yves

Classifications

• G21K1/04

  using variable diaphragms, shutters, choppers · CPC title

• A61N5/103

  Treatment planning systems · CPC title

• A61N2005/1087

  Ions; Protons · CPC title

• A61N5/1043 Primary

  Scanning the radiation beam, e.g. spot scanning or raster scanning · CPC title

• G21K1/10

  Scattering devices; Absorbing devices; Ionising radiation filters · CPC title