High resolution proton beam monitor

• US 20070181815A1
• Filed: 06/30/2005
• Published: 08/09/2007
• Est. Priority Date: 06/30/2004
• Status: Active Grant

• Current Assignee: Lexitek Inc.
• Original Assignee: Lexitek Inc.
• Inventors: Ebstein, Steven
• Granted Patent: US 7,515,681 B2
• Time in Patent Office: Days
• US Class Current: 250/370.110
• CPC Class Codes: A61N 2005/1087 Ions; Protons
• CPC Class Codes: A61N 5/1048 Monitoring, verifying, controlling systems and methods
• CPC Class Codes: G01T 1/02 Dosimeters G01T1/15 takes precedence
• CPC Class Codes: G01T 1/023 Scintillation dose-rate meters
• CPC Class Codes: G01T 1/20 with scintillation detectors
• CPC Class Codes: G01T 1/201 using scintillating fibres
• 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
• CPC Class Codes: G01T 1/2914 Measurement of spatial distribution of radiation

Abstract

A method and apparatus for monitoring a scanning beam of penetrating radiation, such as a scanning proton beam used to irradiate tissue. The position of the beam is tracked in real time by interposing a scintillator film between a source and an object of irradiation. An imaging detector, in optical communication with the scintillator, provides an output that is indicative of the position of the radiation and its variation with time. The accumulated dose over a scan may also be monitored.

Claims

1. A radiation detector for determining spatial distribution of penetrating radiation characterized generally by a propagation direction between a source and an object of irradiation, the radiation detector comprising:

a scintillator, disposed between the source and the object of irradiation, for emitting photons in response to the radiation; and

an imaging detector in optical communication with the scintillator for providing an imaging detector output indicative of the position of the radiation and its variation with time.

2. The radiation detector as set forth in claim 1, further comprising a processor for receiving the imaging detector output and for tracking any variation with time of the spatial distribution of radiation.

3. The radiation detector as set forth in claim 1, further comprising a substrate material for supporting the scintillator in a path between the source and the object of irradiation.

4. The radiation detector as set forth in claim 3, wherein the scintillator is a film deposited upon the substrate.

5. The radiation detector as set forth in claim 1, wherein the scintillator is chosen from a group of inorganic phosphors including P11, P46, and praseodymium-doped Gadox.

6. The radiation detector as set forth in claim 4, wherein the substrate is substantially transparent to visible light.

7. The radiation detector as set forth in claim 1, further including transfer optics for optically coupling the scintillator to the imaging detector.

8. The radiation detector as set forth in claim 1, further including a dosimetric sensor.

9. The radiation detector as set forth in claim 1, further comprising a processor for receiving the imaging detector output and calculating one or moments of the spatial distribution of the penetrating radiation beam.

10. A method for determining a spatial distribution of a beam of penetrating radiation characterized generally by a propagation direction between a source and an object of irradiation, the method comprising:

disposing a film of scintillator material between the source and the object of irradiation, for emitting photons in response to the radiation; and

imaging visible light emitted by the scintillator in response to traversal of the scintillator by penetrating radiation on a path toward the object of irradiation.

11. A method as set forth in claim 10, further comprising generating a imaging output signal characterizing the spatial distribution of the beam.

12. A method as set forth in claim 11, further comprising integrating the imaging output signal over time.

13. A method as set forth in claim 10, further comprising calculating an instantaneous position of the beam.

14. A method as set forth in claim 10, further comprising calculating a first moment of the spatial distribution of the beam.

15. A method as set forth in claim 10, further comprising calculating a second moment of the spatial distribution of the beam.