Method and apparatus for calibrating a radiation therapy treatment system

• US 7,801,269 B2
• Filed: 07/27/2007
• Issued: 09/21/2010
• Est. Priority Date: 07/28/2006
• Status: Active Grant

• Current Assignee: Accuray Incorporated
• Original Assignee: TomoTherapy Incorporated (Accuray Incorporated)
• Inventors: Cravens, Robert L., Lucas, Daniel, Henderson, Douglas, Reckwerdt, Paul J., Olivera, Gustavo H., De Souza, Cleber, Cox, Andrea, Ruchala, Kenneth J., Spence, David Arthur
• Primary Examiner(s): Kiknadze; Irakli
• Application Number:
  US11/881,542
• Publication Number:
  US 20080083871A1
• Time in Patent Office: 1,152 Days
• Field of Search: 378/4, 378/19, 378/62, 378/65, 378/145, 378/146, 378147-150, 378/207, 250/252.1
• US Class Current: 378/65
• CPC Class Codes: A61N 2005/1076 using a dummy object placed in the radiation field, e.g. phantom
• CPC Class Codes: A61N 5/1042 with spatial modulation of the radiation beam within the treatment head
• 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

Abstract

A radiation treatment system and method of commissioning the system, the system including a gantry, a radiation source operable to produce a beam of radiation, and a measurement device. The measurement device is physically connected to the gantry, and includes a multi-dimensional scanning arm, and a detector. The method includes generating radiation from the radiation source, passing the radiation through an attenuation block, and receiving radiation with the measurement device. The measurement device is positioned such that it is not in contact with water. Data is generated from the radiation received and the system is commissioned using the generated data to match system characteristics to a previously defined standard.

Claims

1. A radiation therapy treatment system comprising:

a gantry;

a radiation source coupled to the gantry and operable to produce a beam of radiation; and

a measurement device physically connected to the gantry, the measurement device including

a multi-dimensional scanning arm, and

a detector operable to receive radiation from the radiation source.

2. The radiation therapy treatment system of claim 1, further comprising an attenuation block coupled to the system.

3. The radiation therapy treatment system of claim 2, wherein the attenuation block is movable.

4. The radiation therapy treatment system of claim 3, wherein the attenuation block is movable into and out of the path of the radiation beam produced by the radiation source.

5. The radiation therapy treatment system of claim 2, wherein the attenuation block is not comprised of water.

6. The radiation therapy treatment system of claim 2, wherein the attenuation block is substantially step-shaped.

7. The radiation therapy treatment system of claim 2, wherein the attenuation block comprises a plurality of plates coupled together to form a wedge.

8. The radiation therapy treatment system of claim 7, wherein the plates are of substantially uniform thickness.

9. The radiation therapy treatment system of claim 7, wherein the thickness of each plate is variable to adjust for beam strength.

10. The radiation therapy treatment system of claim 2, wherein the attenuation block is formed of aluminum.

11. The radiation therapy treatment system of claim 2, wherein the attenuation block is formed of plastic.

12. The radiation therapy treatment system of claim 1, wherein the scanning arm moves in any combination of the x, y, and z directions.

13. The radiation therapy treatment system of claim 1, wherein the detector is an ion chamber.

14. The radiation therapy treatment system of claim 13, wherein the detector includes multiple ion chambers.

15. The radiation therapy treatment system of claim 14, wherein the ion chambers are arranged in one of a grid, an array, or a volume.

16. The radiation therapy treatment system of claim 1, wherein the detector includes one of a diode detector or a diamond detector.

17. The radiation therapy treatment system of claim 16, wherein the detector includes a plurality of detectors.

18. The radiation therapy treatment system of claim 17, wherein the plurality of detectors are arranged in one of a grid, an array, or a volume.

19. The radiation therapy treatment system of claim 1, further comprising an adjustment bracket coupled to the radiation source, and wherein the adjustment bracket is operable to adjust the position of the radiation source in both first and second directions, and wherein the movement of the radiation source in each of the first and second directions is independent of the movement in the other of the first and second directions.

20. The radiation therapy treatment system of claim 1, wherein the measurement device includes a plurality of detectors.

21. The radiation therapy treatment system of claim 1, wherein the system has a unified control system for the scanning arm and the gantry.

22. The radiation therapy treatment system of claim 1, wherein the scanning arm is not in contact with water.

23. A method of commissioning a radiation system to a previously defined standard, the radiation system including a measurement device coupled to a gantry and a radiation source capable of producing radiation, the method comprising:

generating radiation from the radiation source;

passing the radiation through an attenuation block;

positioning the measurement device such that it is not in contact with water;

receiving radiation with the measurement device;

generating data from the radiation received; and

commissioning the system using the generated data to match system characteristics to the previously defined standard.

24. The method of claim 23, wherein commissioning the system using the generated data includes comparing the generated data to the previously defined standard.

25. The method of claim 24, wherein commissioning the system further comprises consideration of one or more of the following:

alignment, beam output, beam energy, beam shape, beam symmetry, output fluence rate, wavelength of energy emitted, penetration depth of the radiation, and field width.

26. The method of claim 23, wherein the system includes a collimator located in the path of radiation produced by the radiation source, and wherein generating data from the radiation received includes one of characterizing collimator output, calibrating for multiple field shapes, measuring beam characteristics as a function of the position of the radiation source, and aligning the collimator.

27. The method of claim 23, further comprising moving the attenuation block into and out of the path of the radiation.

28. The method of claim 23, wherein receiving the radiation with the measurement device further comprises receiving the radiation using a detector, and wherein the detector includes an ion chamber.

29. The method of claim 23, further comprising moving the radiation source independently in first and second directions, the movement allowing for adjustment of the position of the radiation source.

30. The method of claim 23, wherein commissioning the system to match system characteristics to the previously defined standard includes matching characteristics to a previously defined standard that is based upon measurements in a water tank.

31. The method of claim 23 wherein the measurement device is independently-calibrated to a known standard.

32. The method of claim 23 wherein the measurement device is an ion chamber.

33. The method of claim 32 wherein the ion chamber is configured to measure electric charge of the radiation received from the radiation source after at least a portion of the radiation passes through the attenuation block.

34. The method of claim 32 wherein the ion chamber is independently-calibrated to a known standard.

35. The method of claim 23 wherein the measurement device is removably coupled to the gantry.

36. The method of claim 23 wherein the measurement device is removably coupled to the gantry and wherein the measurement device moveable to a second radiation system to be commissioned.

37. A method of tuning a radiation therapy system to meet a predefined standard of operating parameters, the radiation therapy system utilizing system controls, the method comprising:

passing radiation through an attenuation block;

collecting data utilizing a measurement device, the data relating to system outputs;

comparing the data to the predefined standard of operating parameters;

providing feedback to the system based on the comparison; and

adjusting the system controls using the feedback so that the system outputs meet the predefined standards.

38. The method of claim 37, wherein the adjustment is automatic.

39. The method of claim 37, wherein the adjustment is manual.

40. The method of claim 37, wherein the radiation therapy system further comprises an attenuation block, and wherein collecting data utilizing the measurement device includes collecting data utilizing a measurement device physically separated from the attenuation block.