Non-collocated imaging and treatment in image-guided radiation treatment systems

• US 20090003523A1
• Filed: 06/29/2007
• Published: 01/01/2009
• Est. Priority Date: 06/29/2007
• Status: Active Grant

• Current Assignee: Accuray Incorporated
• Original Assignee: Accuray Incorporated
• Inventors: Raanes, Chris A., Kuduvalli, Gopinath, Saracen, Michael J., Maurer, Calvin R. JR.
• Granted Patent: US 7,623,623 B2
• Time in Patent Office: Days
• US Class Current: 378/65
• CPC Class Codes: A61B 6/4458 the source unit or the detector unit being attached to robotic arms
• CPC Class Codes: A61B 6/4464 the source unit or the detector unit being mounted to ceiling
• CPC Class Codes: A61N 2005/1054 using a portal imaging system
• CPC Class Codes: A61N 2005/1059 using cameras imaging the patient
• CPC Class Codes: A61N 2005/1062 using virtual X-ray images, e.g. digitally reconstructed radiographs [DRR]
• CPC Class Codes: A61N 2005/1063 maintaining the position when the patient is moved from an imaging to a therapy system
• CPC Class Codes: A61N 5/1049 for verifying the position of the patient with respect to the radiation beam
• CPC Class Codes: A61N 5/1069 Target adjustment, e.g. moving the patient support

Abstract

An image-guided radiation treatment system includes a robotic positioning system and a tracking system that enables a radiation target to be imaged and aligned at one location and treated at another location by transferring positional data from the imaging system to the positioning system and the radiation treatment system.

Claims

1. A method, comprising:

imaging a volume of interest (VOI) with an imaging system and acquiring positional data of a target within the VOI, wherein the positional data comprises a present position of the target relative to an imaging center of the imaging system, wherein the imaging center has a first location in a treatment room coordinate system;

moving the VOI with a positioning system, to align the target in a radiation system, wherein the radiation system has a second location in the treatment room coordinate system different from the first location; and

treating the target at the second location.

2. The method of claim 1, further comprising detecting movement of the VOI in the radiation system.

3. The method of claim 1, wherein imaging the VOI in the imaging system comprises:

acquiring 2D x-ray images of the VOI with the imaging system in each of two or more projections; and

comparing the 2D x-ray images in each of the two or more projections with DRRs of the VOI to locate the target in the imaging system.

4. The method of claim 1, wherein acquiring the positional data comprises determining a first transformation between the present position of the target in the imaging system and the reference position of the target at the imaging center of the imaging system.

5. The method of claim 4, wherein moving the VOI comprises:

moving the VOI from the imaging system to the radiation system over a difference vector comprising a difference between the imaging center and a radiation treatment center in the radiation system in the treatment room coordinate system; and

aligning the target in the radiation system in conformance with a treatment plan.

6. The method of claim 5, wherein aligning the target in the radiation system comprises moving the VOI through the first transformation with the positioning system to align the target at the radiation treatment center.

7. The method of claim 5, wherein aligning the target comprises moving the radiation system through the inverse of the first transformation to align the radiation treatment center with the target.

8. The method of claim 2, wherein detecting movement of the VOI in the radiation system comprises:

determining a reference position of the VOI in the radiation system, with a tracking system, after aligning the target at the radiation treatment center;

tracking the position of the VOI in the radiation system, during radiation treatment, with the tracking system; and

determining a second transformation between the reference position of the VOI in the radiation system and the position of the VOI during the radiation treatment.

9. The method of claim 8, further comprising realigning the target in the radiation system if a magnitude of the second transformation is less than a predetermined magnitude, wherein realigning the target comprises one of moving the VOI through the second transformation and moving the radiation system through the inverse of the second transformation.

10. The method of claim 8, further comprising halting the radiation system if the second transformation exceeds a predetermined magnitude.

11. The method of claim 10, further comprising returning the VOI to the imaging system over the inverse of the difference vector and determining the position of the target in the imaging system relative to the reference position of the target at the imaging center of the imaging system.

12. The method of claim 4, further comprising moving the VOI through the first transformation with the positioning system to align the target at the imaging center of the imaging system with the reference position of the target at the imaging center of the imaging system.

13. The method of claim 12, wherein moving the VOI comprises moving the VOI from the imaging system to the radiation system over a difference vector comprising a difference between the imaging center and a radiation treatment center in the radiation system in the treatment room coordinate system, wherein the target is aligned at the radiation treatment center in conformance with a treatment plan.

14. The method of claim 13, wherein detecting movement of the VOI in the radiation system comprises:

determining a reference position of the VOI in the radiation system, with a tracking system, when the target is aligned at the radiation treatment center;

tracking the position of the VOI in the radiation system, during radiation treatment; and

determining a second transformation between the reference position of the VOI in the radiation system and the position of the VOI during the radiation treatment.

15. The method of claim 14, further comprising realigning the target in the radiation system if a magnitude of the second transformation is less than a predetermined magnitude, wherein realigning the target comprises one of moving the VOI through the second transformation and moving the radiation system through the inverse of the second transformation.

16. The method of claim 14, further comprising halting the radiation system if the second transformation exceeds a predetermined magnitude.

17. The method of claim 16, further comprising returning the VOI to the imaging system over the inverse of the difference vector and determining the position of the target in the imaging system relative to the reference position of the target at the imaging center of the imaging system.

18. The method of claim 12, wherein detecting movement of the VOI in the radiation system comprises:

acquiring a 2D portal image of the VOI in the radiation system corresponding to a selected projection in the imaging system;

comparing the 2D portal image of the VOI with a 2D reference image of the VOI in the selected projection, wherein the 2D reference image of the VOI comprises a 2D reference x-ray image acquired by the imaging system after the target is aligned with the reference position of the target in the imaging system.

19. The method of claim 18, further comprising determining a second transformation between the 2D portal image and the 2D reference image.

20. The method of claim 19, further comprising realigning the target in the radiation system if a magnitude of the second transformation is less than a predetermined magnitude, wherein realigning the target comprises moving the VOI through the second transformation.

21. The method of claim 19, further comprising halting the radiation system if the second transformation exceeds a predetermined magnitude.

22. The method of claim 21, further comprising returning the VOI to the imaging system over the inverse of the difference vector and determining the position of the target in the imaging system relative to the reference position of the target at the imaging center of the imaging system.

23. A system, comprising:

an imaging system configured to image a volume of interest (VOI) to acquire positional data of a target within the VOI, wherein the positional data comprises a present position of the target relative to a reference position of the target at an imaging center of the imaging system, and wherein the imaging center has a first location in a treatment room coordinate system;

a radiation system configured to apply a radiation treatment beam to the target; and

a positioning system configured to move the VOI from the imaging system to the radiation system to align the target in the radiation system, wherein the radiation system has a second location in the treatment room coordinate system different from the first location.

24. The system of claim 23, further comprising a tracking system configured to track the VOI from the imaging system to the radiation system and to detect movement of the VOI in the radiation system.

25. The system of claim 23, wherein to image the VOI the imaging system is configured to:

acquire 2D x-ray images of the VOI in each of two or more projections; and

to

compare the 2D x-ray images in each of the two or more projections with reference DRRs of the VOI to locate the target in the imaging system.

26. The system of claim 23, wherein to acquire the positional data, the imaging system is configured to determine a first transformation between the present position of the target in the imaging system and the reference position of the target at the imaging center of the imaging system.

27. The system of claim 26, wherein the positioning system is configured to

move the VOI from the imaging system to a radiation treatment center in the radiation system over a difference vector comprising a difference between the imaging center and the radiation treatment center in the treatment room coordinate system;

and to

align the target in the radiation system in conformance with a treatment plan.

28. The system of claim 27, wherein to align the target in the radiation system, the positioning system is further configured to move the VOI through the first transformation to align the target at the radiation treatment center.

29. The system of claim 27, wherein to align the target in the radiation system, the radiation system is configured to move through the inverse of the first transformation to align the radiation treatment center with the target.

30. The system of claim 24, wherein to detect movement of the VOI in the radiation system, the tracking system is configured to

determine a reference position of the VOI in the radiation system after the target is aligned at the radiation treatment center, to

track the position of the VOI in the radiation system during radiation treatment, and to

determine a second transformation between the reference position of the VOI in the radiation system and the position of the VOI during the radiation treatment.

31. The system of claim 30, wherein the positioning system is further configured to move the VOI through the second transformation to realign the target with the radiation treatment center if a magnitude of the second transformation is less than a specified magnitude.

32. The system of claim 30, wherein the radiation system is configured to move through the inverse of the second transformation realign the radiation treatment center with the target if a magnitude of the second transformation is less than a specified magnitude.

33. The system of claim 30, wherein the radiation system is configured to halt radiation treatment if the second transformation exceeds the predetermined magnitude.

34. The system of claim 33, wherein the positioning system is configured to return the VOI to the imaging system over the inverse of the difference vector and wherein the imaging system is configured to determine the position the target in the imaging system relative to the reference position of the target at the imaging center of the imaging system.

35. The system of claim 26, wherein the positioning system is configured to move the VOI through the first transformation to align the target at the imaging center of the imaging system with the reference position of the target at the imaging center of the imaging system.

36. The system of claim 35, wherein the positioning system is further configured to move the VOI from the imaging system to the radiation system over a difference vector comprising a difference between the imaging center and the radiation treatment center in the treatment room coordinate system, wherein the target is aligned at the radiation treatment center.

37. The method of claim 36, wherein to detect movement of the VOI in the radiation system, the tracking system is configured to:

determine a reference position of the VOI in the radiation system when the target is aligned at the radiation treatment center;

to

track the position of the VOI in the radiation system, during radiation treatment; and

to

determine a second transformation between the reference position of the VOI in the radiation system and the position of the VOI during the radiation treatment.

38. The system of claim 37, wherein the positioning system is configured to realign the target in the radiation system by moving the VOI through the second transformation if a magnitude of the second transformation is less than a predetermined magnitude.

39. The system of claim 37, wherein the radiation system is configured to halt the radiation treatment if the second transformation exceeds a predetermined magnitude.

40. The system of claim 39, wherein the positioning system is configured to return the VOI to the imaging system over the inverse of the difference vector and to determine the position of the target in the imaging system relative to the reference position of the target at the imaging center of the imaging system.

41. A system, comprising:

an imaging system configured to image a volume of interest (VOI) to acquire positional data of a target within the VOI, wherein the positional data comprises a present position of the target relative to a reference position of the target at an imaging center of the imaging system, and wherein the imaging center has a first location in a treatment room coordinate system;

a radiation system including a portal imaging device, wherein the radiation system is configured to apply a radiation treatment beam to the target and to capture electronic portal images of the VOI; and

a positioning system configured to move the VOI from the imaging system to the radiation system to align the target at in the radiation system, wherein the radiation system has a second location in the treatment room coordinate system different from the first location.

42. The system of claim 41, wherein the portal imaging device is configured to detect movement of the VOI in the radiation system.

43. The system of claim, 41, wherein to image the VOI the imaging system is configured to:

acquire 2D x-ray images of the VOI in each of two or more projections; and

to

compare the 2D x-ray images in each of the two or more projections with reference DRRs of the VOI to locate the target in the imaging system.

44. The system of claim 41, wherein to acquire the positional data, the imaging system is configured to determine a first transformation between the present position of the target in the imaging system and the reference position of the target at the imaging center of the imaging system.

45. The system of claim 44, wherein the positioning system is configured to apply the first transformation to the VOI to align the target with the reference position of the target at the imaging center of the imaging system.

46. The system of claim 45, wherein the positioning system is configured to move the VOI from the imaging system to the radiation system over a difference vector comprising a difference between the imaging center and a radiation treatment center in the radiation system in the treatment room coordinate system to align the target at the radiation treatment center in the radiation system.

47. The system of claim 42, wherein to detect movement of the VOI in the radiation system, the portal imaging device is configured to:

acquire a 2D portal image of the VOI in the radiation system corresponding to a selected projection of the VOI in the imaging system; and

to

compare the 2D portal image of the VOI with the 2D reference image of the VOI in the selected projection, wherein the 2D reference image of the VOI comprises a 2D reference x-ray image acquired by the imaging system after the target is aligned with the reference position of the target at the imaging center.

48. The system of claim 47, wherein the radiation system is further configured to determine a second transformation between the 2D portal image and the 2D reference image.

49. The system of claim 48, wherein the positioning system is configured realign the target in the radiation system by moving the VOI through the second transformation if a magnitude of the second transformation is less than a specified magnitude.

50. The system of claim 48, wherein the radiation system is configured to halt the radiation treatment if a magnitude of the second transformation exceeds a specified magnitude.

51. The system of claim 50, wherein the positioning system is configured to return the VOI to the imaging system over the inverse of the difference vector and wherein the imaging system is configured to determine the position the target in the imaging system relative to the reference position of the target at the imaging center of the imaging system.

52. An apparatus, comprising:

means for imaging and treating a radiation target at different locations to prevent interference between an imaging system and a radiation treatment system; and

means for detecting movement of the radiation target in the radiation treatment system.

53. The apparatus of claim 52, further comprising means for compensating for the movement of the radiation target.

54. The apparatus of claim 52, further comprising means for correcting the movement of the radiation target.