Multi-resolution detectors for measuring and controlling a charged particle pencil beam

• US 9,427,599 B1
• Filed: 02/26/2015
• Issued: 08/30/2016
• Est. Priority Date: 02/26/2015
• Status: Active Grant

• Current Assignee: Pyramid Technical Consultants, Inc.
• Original Assignee: Pyramid Technical Consultants, Inc.
• Inventors: Boisseau, R. Paul, Dart, Andrew, Gordon, John, Ota, Kan
• Primary Examiner(s): Kim, Kiho
• Application Number:
  US14/632,270
• Publication Number:
  US 20160250500A1
• Time in Patent Office: 551 Days
• US Class Current: 1/1
• CPC Class Codes: A61N 2005/1074 Details of the control system, e.g. user interfaces
• CPC Class Codes: A61N 2005/1087 Ions; Protons
• CPC Class Codes: A61N 5/1048 Monitoring, verifying, controlling systems and methods
• CPC Class Codes: A61N 5/1075 for testing, calibrating, or quality assurance of the radiation treatment apparatus
• CPC Class Codes: A61N 5/1077 Beam delivery systems
• CPC Class Codes: H01J 47/02 Ionisation chambers

Abstract

A multi-resolution detector includes a high-resolution pixelated electrode and a low-resolution pixelated electrode. The high-resolution pixelated electrode includes a plurality of sub-arrays of first pixels. Each respective first pixel at each relative position in each sub-array is electrically connected in parallel with one another. The low-resolution pixelated electrode includes a plurality of second pixels. A control system receives as inputs an output from each pixelated detector. The control system uses the inputs to determine a physical position and a transverse intensity distribution of an incident charged particle pencil beam at the resolution of the high-resolution pixelated electrode.

Claims

1. A system for detecting a characteristic of a charged particle pencil beam, the system comprising:

a multi-resolution detector disposed proximal to an isocenter plane, said multi-resolution detector comprising;

a first pixelated electrode comprising a plurality of sub-arrays of first pixels, wherein each respective first pixel at each relative position in each sub-array is electrically connected in parallel with one another, such that said first pixelated electrode dynamically generates a first output representing a combined electrical output of said respective first pixels from said sub-arrays, said first pixels detecting an electrical current created by said charged particle pencil beam;

a second pixelated electrode comprising a plurality of second pixels, said second pixelated electrode configured to dynamically generate a second output representative of an approximate physical position of the charged particle pencil beam in a plane substantially parallel to said isocenter plane, said second pixelated electrode having a second resolution less than a first resolution of said first pixelated electrode; and

a high-voltage plane disposed between said first and second pixelated electrodes;

a diagnostic control system comprising a memory and a processor, the diagnostic control system configured to receive as inputs the first output and the second output and to determine an actual position and an actual transverse intensity distribution of said charged particle beam based on said first and second outputs, said actual position and said actual intensity distribution having said first resolution.

2. The system of claim 1, wherein said diagnostic control system is configured to transmit said actual position and said actual intensity distribution to a beam control system.

3. The system of claim 2, wherein said beam control system updates a calibration parameter based on at least one of said actual position and said actual intensity distribution.

4. The system of claim 1, wherein a first gas gap is defined between said first pixelated electrode and said high voltage plane.

5. The system of claim 4, wherein a second gas gap is defined between said high voltage plane and said second pixelated electrode.

6. The system of claim 1, wherein said first pixel has a first size and said second pixel has a second size, said first size less than said second size.

7. The system of claim 1, wherein said first pixelated electrode is disposed in a first plane and said second pixelated electrode is disposed in a second plane such that said first plane, said second plane, and said high-voltage plane are substantially parallel to said isocenter plane.

8. A system for detecting a characteristic of a charged particle pencil beam, the system comprising:

a multi-resolution detector system disposed proximal to an isocenter plane, said multi-resolution detector comprising;

a first pixelated detector comprising a first pixelated electrode having a plurality of sub-arrays of first pixels, wherein each respective first pixel at each relative position in each sub-array is electrically connected in parallel with one another, such that said first pixelated detector dynamically generates a first output representing a combined electrical output of said respective first pixels from said sub-arrays, said first pixels detecting an electrical current created by said charged particle pencil beam; and

a second pixelated detector comprising a second pixelated electrode having a plurality of second pixels, said second pixelated detector configured to dynamically generate a second output representative of an approximate physical position of the charged particle pencil beam in a plane substantially parallel to said isocenter plane, said second pixelated electrode having a second resolution less than a first resolution of said first pixelated electrode;

a diagnostic control system comprising a processor, the control system configured to receive as inputs the first output and the second output and to determine an actual position and an actual transverse intensity distribution of said charged particle beam based on said first and second outputs, said actual position and said actual intensity distribution having said first resolution.

9. The system of claim 8, wherein said diagnostic control system is configured to transmit said actual position and said actual intensity distribution to a beam control system.

10. The system of claim 9, wherein said beam control system updates a calibration parameter based on at least one of said actual position and said actual intensity distribution.

11. The system of claim 8, wherein a first gas gap is defined between said first pixelated electrode and said high voltage plane.

12. The system of claim 11, wherein a second gas gap is defined between said high voltage plane and said second pixelated electrode.

13. The system of claim 8, wherein said first pixel has a first size and said second pixel has a second size, said first size less than said second size.

14. The system of claim 8, wherein said first pixelated electrode is disposed in a first plane and said second pixelated electrode is disposed in a second plane such that said first plane, said second plane, and said high-voltage plane are substantially parallel to said isocenter plane.

15. A method of characterizing a charged particle pencil beam, said method comprising:

receiving a combined electrical output generated by a charged particle pencil beam with a first pixelated electrode comprising a plurality of sub-arrays of first pixels having a first resolution, wherein each respective first pixel at each relative position in each sub-array is electrically connected in parallel with one another;

determining an approximate physical position of said charged particle pencil beam with electrical output data from a second pixelated electrode, said second pixelated electrode comprising a plurality of second pixels having a second resolution, said second resolution lower than said first resolution; and

calculating an actual physical position and an actual transverse intensity distribution of said charged particle pencil beam using said combined electrical output and said approximate physical position, said actual physical position and said actual transverse intensity distribution having said first resolution.

16. The method of claim 15, further comprising disposing a multi-resolution detector proximal to an isocenter plane, said multi-resolution detector comprising said first and second pixelated electrodes.

17. The method of claim 15, further comprising disposing a first pixelated detector and a second pixelated detector proximal to an isocenter plane, said first pixelated detector comprising said first pixelated electrode, said second pixelated detector comprising said second pixelated electrode.

18. The method of claim 15, further comprising updating a calibration parameter in a beam control system based on at least one of said actual physical position and said actual intensity distribution.

19. The method of claim 15, further comprising disposing a multi-resolution detector between an isocenter plane and a magnetic field generator, said multi-resolution detector comprising said first and second pixelated electrodes.

20. The method of claim 19, further comprising transmitting a control signals to a charged particle beam generator, said control signal based on at least one of said actual physical position and said actual transverse intensity distribution of said charged particle pencil beam.

21. The method of claim 19, further comprising transmitting a control signal to a magnetic field generator based on said actual location, said control signal based on at least one of said actual physical position and said actual transverse intensity distribution of said charged particle pencil beam.

22. The method of claim 19, wherein said first pixel has a first size and said second pixel has a second size, said first size less than said second size.

23. An integrated multi-resolution detector comprising:

a first pixelated electrode disposed in a first plane, said first pixelated electrode comprising a plurality of sub-arrays of first pixels, wherein each respective first pixel at each relative position in each sub-array is electrically connected in parallel with one another, such that said first pixelated electrode dynamically generates a first output representing a combined electrical output of said respective first pixels from said sub-arrays, said first pixels detecting an electrical current created by a charged particle pencil beam;

a second pixelated electrode disposed in a second plane, said second pixelated electrode comprising a plurality of second pixels, said second pixelated electrode configured to dynamically generate a second output representative of a physical position of said charged particle pencil beam in said second plane, said second pixelated electrode having a second resolution less than a first resolution of said first pixelated electrode; and

a high-voltage plane disposed between said first and second pixelated electrodes, wherein said first plane, said second plane, and said high-voltage plane are substantially parallel to one another.

24. The detector of claim 23, wherein said first pixel has a first size and said second pixel has a second size, said first size less than said second size.