Method and apparatus for calibrating a charged particle pencil beam used for therapeutic purposes

• US 9,333,376 B2
• Filed: 03/09/2015
• Issued: 05/10/2016
• Est. Priority Date: 03/07/2014
• Status: Active Grant

• Current Assignee: Pyramid Technical Consultants, Inc.
• Original Assignee: Pyramid Technical Consultants, Inc.
• Inventors: Boisseau, R. Paul, Gordon, John, Nett, William P.
• Primary Examiner(s): Vanore, David A
• Application Number:
  US14/641,932
• Publication Number:
  US 20150251021A1
• Time in Patent Office: 428 Days
• Field of Search: 378/16, 378/19, 378/207, 378/95, 250/252.1, 250/354.1, 250/492.1, 250/505.1
• US Class Current: 1/1
• CPC Class Codes: A61N 2005/1087 Ions; Protons
• CPC Class Codes: A61N 5/1075 for testing, calibrating, or quality assurance of the radiation treatment apparatus
• CPC Class Codes: G01T 1/29 Measurement performed on radiation beams, e.g. position or section of the beam; Measurement of spatial distribution of radiation

Abstract

A system for calibrating a charged particle pencil beam includes a first pixelated detector, a second pixelated detector, a beam stop, and a diagnostics system. The first and second pixelated detectors measure the pencil beam at positions proximal and/or distal to an isocenter plane. The beam stop is configured to detect an energy level of the pencil beam. The diagnostics system is configured to transmit a signal to request a generation of the charged particle pencil beam at different settings. The diagnostics system is also configured to update a calibration parameter for each setting based on the data received from the pixelated detectors and the beam stop.

Claims

1. A system for calibrating a charged particle pencil beam, the system comprising:

a first pixelated detector disposed at a proximal position to an isocenter plane, the first pixelated detector configured to provide a first output representative of first data of the charged particle pencil beam;

a second pixelated detector disposed at a first position distal to the isocenter plane, the second pixelated detector configured to provide a second output representative of second data of the charged particle pencil beam; and

a beam stop disposed at a second position distal to the second pixelated detector, the beam stop configured to provide a third output representative of an energy of the charged particle pencil beam, wherein the second pixelated detector is disposed between the isocenter plane and the beam stop;

a diagnostics system comprising a processor and a memory, the diagnostics system configured (a) to transmit a signal to request a generation of the charged particle pencil beam at a plurality of settings; and

(b) to update a calibration parameter for each setting based on at least one of the first output, the second output, and the third output.

2. The system of claim 1, wherein the settings include an energy level of the charged particle pencil beam.

3. The system of claim 2, wherein the third output is representative of a kinetic energy of the charged particle pencil beam.

4. The system of claim 2, wherein the third output is representative of a total current of the charged particle pencil beam.

5. The system of claim 1, wherein the settings include a respective trajectory of the charged particle pencil beam.

6. The system of claim 5, wherein the first data includes a first measurement of a first transverse intensity distribution of the charged particle pencil beam and the second data includes a second measurement of a second transverse intensity distribution of the charged particle pencil beam.

7. The system of claim 5, wherein the trajectory includes at least one of a deflection angle or a gantry angle.

8. The system of claim 1, wherein the settings include a respective focus of the charged particle pencil beam.

9. The system of claim 8, wherein the first data includes a first measurement of a first transverse intensity distribution of the charged particle pencil beam and the second data includes a second measurement of a second transverse intensity distribution of the charged particle pencil beam.

10. The system of claim 9, wherein the diagnostics system is configured to determine a divergence angle of the charged particle pencil beam.

11. The system of claim 1, wherein the diagnostics system is in communication with a pencil beam control system.

12. The system of claim 11, wherein the diagnostics system is configured to transmit the request signal to the control system.

13. The system of claim 11, wherein the diagnostics system is configured to transmit the updated calibration parameter to the control system.

14. The system of claim 13, wherein the control system is configured to modify a beam control signal based on the updated calibration parameter.

15. The system of claim 1, further comprising a support arm mechanically connected to the first and second pixelated detectors, the support arm mechanically connected to a motion system for adjusting a position of the first and second pixelated detectors along an axis parallel to the isocenter plane.

16. The system of claim 15, comprising a rotation mechanism mechanically connected to the first and second pixelated detectors.

17. A method for calibrating a charged particle pencil beam system, the method comprising:

(a) transmitting a signal to request a generation of the charged particle pencil beam at a plurality of settings;

(b) receiving, for each setting, first data representing a first transverse intensity distribution of the charged particle pencil beam at a first position, said first position proximal to an isocenter plane;

(c) receiving, for each setting, second data representing a second transverse intensity distribution of the charged particle pencil beam at a second position, said second position distal to the isocenter plane;

(d) receiving, for each setting, third data representing an energy measurement of the charged particle pencil beam; and

(e) updating a calibration parameter for each setting based on at least one of the first data, the second data, and the third data.

18. The method of claim 17, wherein the settings include at least one of a focus, a magnetic field strength, a deflection angle, a gantry angle, and an energy level of the charged particle pencil beam.

19. The method of claim 17, further comprising determining a first centroid position of the first transverse intensity distribution and a second centroid position of the second transverse intensity distribution.

20. The method of claim 17, wherein updating the calibration parameter includes comparing a model beam characteristic with a measured beam characteristic.

21. The method of claim 20, wherein the model beam characteristic includes a model energy setting and the measured beam characteristic includes the energy measurement represented in the third data.

22. The method of claim 20, further comprising aligning a first pixelated detector disposed at the first position and a second pixelated detector disposed at the second position with an x-ray source.

23. The method of claim 17, further comprising adjusting at least one of the first position and the second position based on a trajectory of the charged particle pencil beam.