Fiducial-less tracking of a volume of interest

• US 20080109013A1
• Filed: 11/03/2006
• Published: 05/08/2008
• Est. Priority Date: 11/03/2006
• Status: Active Grant

• Current Assignee: Accuray Incorporated
• Original Assignee: Accuray Incorporated
• Inventors: Berlinger, Kajetan R., Fu, Dongshan
• Granted Patent: US 8,831,706 B2
• Time in Patent Office: Days
• US Class Current: 606/130
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/037 Emission tomography
• 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: A61B 6/5217 extracting a diagnostic or physiological parameter from medical diagnostic data
• CPC Class Codes: A61N 2005/1062 using virtual X-ray images, e.g. digitally reconstructed radiographs [DRR]
• CPC Class Codes: A61N 5/1037 taking into account the movement of the target, e.g. 4D-image based planning
• CPC Class Codes: A61N 5/1049 for verifying the position of the patient with respect to the radiation beam
• CPC Class Codes: G16H 50/30 for calculating health indices; for individual health risk assessment

Abstract

A method and an apparatus for fiducial-less tracking of a volume of interest (VOI) have been presented. In some embodiments, a pair of intra-operative images of a portion of a patient is generated during treatment of a target region in the patient to show a bony structure of the patient. The bony structure shown is movable responsive to respiration of the patient. Then the pair of intra-operative images is compared with a set of digitally reconstructed radiograph (DRR) pairs, generated from volumes of four-dimensional (4D) diagnostic imaging data, to determine a location of the movable bony structure that corresponds to a particular volume of the 4D diagnostic imaging data.

Claims

1. A method comprising:

generating a pair of intra-operative images of a portion of a patient during treatment of a target region in the patient to show a movable bony structure of the patient, wherein the movable bony structure moves responsive to respiration of the patient; and

comparing the pair of intra-operative images with a plurality of digitally reconstructed radiograph (DRR) pairs, generated from a plurality of volumes of four-dimensional (4D) diagnostic imaging data, to determine a location of the movable bony structure that corresponds to a particular volume of the plurality of volumes of 4D diagnostic imaging data.

2. The method of claim 1, further comprising:

correlating the location of the movable bony structure in the particular volume of the plurality of volumes of 4D diagnostic imaging data with a location of the target region in the particular one of the plurality of volumes of 4D diagnostic imaging data to determine a location of the target region at time of the generating of the pair of intra-operative images.

3. The method of claim 2, further comprising:

defining a target region motion pattern based on locations of the target region in the plurality of volumes of 4D diagnostic imaging data, wherein the plurality of volumes of 4D diagnostic imaging data are captured at different intervals within a breathing cycle of the patient.

4. The method of claim 3, wherein the comparing the pair of intra-operative images with the plurality of DRR pairs comprises:

generating a similarity curve.

5. The method of claim 4, further comprising:

determining an intra-operative location of the target region at time of the generating of the pair of intra-operative images based on the similarity curve and the target region motion pattern.

6. The method of claim 1, further comprising:

registering a spine of the patient to globally align the patient prior to beginning the treatment.

7. The method of claim 1, further comprising:

generating the plurality of DRR pairs from the plurality of volumes of 4D diagnostic imaging data.

8. The method of claim 7, wherein generating the plurality of DRR pairs comprises:

segmenting an image of static bony structure from each of the plurality of volumes of 4D diagnostic imaging data to generate the plurality of DRR pairs; and

removing the image of the static bony structure from the plurality of DRR pairs.

9. The method of claim 1, wherein the plurality of volumes of 4D diagnostic imaging data comprise a plurality of volumes of 4D computerized tomography (CT) data.

10. The method of claim 9, wherein the plurality of volumes of 4D CT data comprise a plurality of three-dimensional images, where each of the plurality of three-dimensional images represents a different point in a motion cycle.

13. The method of claim 11, further comprising:

correlating a location of the target region with a location of the movable bony structure in each of the plurality of volumes of 4D diagnostic imaging data; and

defining a target region motion pattern based on result of the correlating.

14. The method of claim 11, further comprising:

generating at least one of the plurality of volumes of 4D diagnostic imaging data at each of a plurality of intervals within a breathing cycle of the patient, wherein the movable bony structure and the target region move in response to respiration of the patient.

15. The method of claim 14, wherein the plurality of volumes of 4D diagnostic imaging data comprises a plurality of volumes of 4D computerized tomography (CT) data.

16. The method of claim 15, wherein the plurality of volumes of 4D CT data comprise a plurality of three-dimensional images, where each of the plurality of three-dimensional images represents a different point in a motion cycle.

17. The method of claim 11, wherein the plurality of 2D images comprise a plurality of 2D digitally reconstructed radiograph (DRR) pairs.

18. The method of claim 17, further comprising:

generating a pair of intra-operative images during treatment delivery; and

comparing the pair of intra-operative images with the plurality of DRR pairs to determine the location of the target region during treatment delivery.

19. The method of claim 18, wherein the pair of intra-operative images comprise a pair of x-ray images.

11. A method comprising:

segmenting an image of a static bony structure from each of a plurality of volumes of four-dimensional (4D) diagnostic imaging data of a volume of interest (VOI) in a patient prior to treating a target region in the patient to generate a plurality of two-dimensional (2D) images to determine a location of the target region during treatment delivery, wherein the VOI comprises the static bony structure and a movable bony structure, the movable bony structure moving in response to respiration of the patient; and

removing the image of the static bony structure from each of the plurality of 2D images.

12. The method of claim 11, wherein the movable bony structure is outside of the target region.

20. The method of claim 11, wherein segmenting the image of the static bony structure comprises:

generating a transversal view of the VOI; and

computing a frontal cut and a sagittal cut of the VOI.

21. An apparatus comprising:

a two-dimensional (2D) image generation module to generate 2D images from four-dimensional (4D) diagnostic imaging data of a portion of a patient, wherein each of the 2D images shows a static bony structure and a bony structure movable responsive to respiration of the patient; and

a segmentation module coupled to the 2D image generation module to segment the static bony structure in each of the 2D images and to remove the static bony structure from each of the 2D images.

22. The apparatus of claim 21, further comprising:

a motion pattern defining module to define a motion pattern for a target region within the patient based on a reference volume of 4D diagnostic imaging data, wherein the motion pattern correlates movement of the target region with movement of the movable bony structure.

23. The apparatus of claim 22, further comprising:

a treatment planning system comprising the 2D image generation module, the segmentation module, and the motion pattern defining module; and

a treatment delivery system coupled to the treatment planning system to deliver radiosurgical treatment to the target region at a location in the patient determined using the motion pattern and the 2D images with the static bony structure removed.

24. The apparatus of claim 23, wherein the treatment delivery system comprises:

an intra-operative imaging device to generate a plurality of intra-operative images of the portion of the patient.

25. The apparatus of claim 24, wherein the treatment delivery system further comprises:

a correlating module to correlate the 2D images with the intra-operative images; and

a target region locator coupled to the correlating module to determine an intra-operative location of the target region based on result from the correlating module and the motion pattern from the motion pattern defining module.

26. The apparatus of claim 25, wherein the treatment delivery system further comprises:

a linear accelerator (LINAC) mounted to a robotic arm, to provide radiation.

27. The apparatus of claim 25, wherein the treatment delivery system further comprises:

a linear accelerator (LINAC) mounted to a gantry, to provide radiation.

28. The apparatus of claim 27, wherein the LINAC is mounted on a gimbaled head assembly.

29. An apparatus comprising:

means for generating a plurality of two-dimensional (2D) images from four-dimensional (4D) diagnostic imaging data of a portion of a patient before delivering treatment to a target region within the patient; and

means for tracking the target region in the patient using the plurality of 2D images to determine an intra-operative location of the target region without implanting fiducials in the patient, wherein the target region moves during treatment.

30. The apparatus of claim 29, wherein the means for performing fiducial-less tracking of the target region comprises:

means for correlating a position of the target region and a position of a bony structure of the patient, movable responsive to respiration of the patient, at each of a plurality of stages within a breathing cycle based on the 4D diagnostic imaging data.

31. The apparatus of claim 29, wherein the means for performing fiducial-less tracking of the target region comprises:

means for segmenting a static bony structure in the plurality of 2D images; and

means for removing the static bony structure from the plurality of 2D images.

32. A machine-readable medium that provides instructions that, if executed, will perform operations comprising:

generating a pair of intra-operative images of a portion of a patient during treatment of a target region in the patient to show a movable bony structure of the patient, wherein the movable bony structure moves responsive to respiration of the patient; and

comparing the pair of intra-operative images with a plurality of digitally reconstructed radiograph (DRR) pairs, generated from a plurality of volumes of four-dimensional (4D) diagnostic imaging data, to determine a location of the movable bony structure that corresponds to a particular volume of the plurality of volumes of 4D diagnostic imaging data.

33. The machine-readable medium of claim 32, wherein the operations further comprise:

correlating the location of the movable bony structure in the particular volume of the plurality of volumes of 4D diagnostic imaging data with a location of the target region in the particular one of the plurality of volumes of 4D diagnostic imaging data to determine a location of the target region at time of the generating of the pair of intra-operative images.

34. The machine-readable medium of claim 33, wherein the operations further comprise:

defining a target region motion pattern based on locations of the target region in the plurality of volumes of 4D diagnostic imaging data, wherein the plurality of volumes of 4D diagnostic imaging data are captured at different intervals within a breathing cycle of the patient.

35. The machine-readable medium of claim 34, wherein the comparing the pair of intra-operative images with the plurality of DRR pairs comprises:

generating a similarity curve.

36. The machine-readable medium of claim 35, wherein the operations further comprise:

determining a location of the target region at time of the generating of the pair of intra-operative images based on the similarity curve and the target region motion pattern.

37. The machine-readable medium of claim 32, wherein the operations further comprise:

registering a spine of the patient to globally align the patient prior to beginning the treatment.

38. The machine-readable medium of claim 32, wherein the operations further comprise:

generating the plurality of DRR pairs from the plurality of volumes of 4D diagnostic imaging data.

39. The machine-readable medium of claim 38, wherein generating the plurality of DRR pairs comprises:

segmenting an image of static bony structure from each of the plurality of volumes of 4D diagnostic imaging data to generate the plurality of DRR pairs; and

removing the image of the static bony structure from the plurality of DRR pairs.

40. The machine-readable medium of claim 32, wherein the plurality of volumes of 4D diagnostic imaging data comprise a plurality of volumes of 4D computerized tomography (CT) data.

41. The machine-readable medium of claim 40, wherein the plurality of volumes of 4D CT data comprise a plurality of three-dimensional images, where each of the plurality of three-dimensional images represents a different point in a motion cycle.

42. A machine-readable medium that provides instructions that, if executed, will perform operations comprising:

segmenting an image of a static bony structure from each of a plurality of volumes of four-dimensional (4D) diagnostic imaging data of a volume of interest (VOI) in a patient prior to treating a target region in the patient to generate a plurality of two-dimensional (2D) images to determine a location of the target region during treatment delivery, wherein the VOI comprises the static bony structure and a movable bony structure, the movable bony structure moving in response to respiration of the patient; and

removing the image of the static bony structure from each of the plurality of 2D images.

43. The machine-readable medium of claim 42, wherein the movable bony structure is outside of the target region.

44. The machine-readable medium of claim 42, wherein the operations further comprise:

correlating a location of the target region with a location of the movable bony structure in each of the plurality of volumes of 4D diagnostic imaging data; and

defining a target region motion pattern based on result of the correlating.

45. The machine-readable medium of claim 42, wherein the operations further comprise:

generating at least one of the plurality of volumes of 4D diagnostic imaging data at each of a plurality of intervals within a breathing cycle of the patient, wherein the movable bony structure and the target region move in response to respiration of the patient.

46. The machine-readable medium of claim 45, wherein the plurality of volumes of 4D diagnostic imaging data comprises a plurality of volumes of 4D computerized tomography (CT) data.

47. The machine-readable medium of claim 42, wherein the plurality of volumes of 4D CT data comprise a plurality of three-dimensional images, where each of the plurality of three-dimensional images represents a different point in a motion cycle.

48. The machine-readable medium of claim 42, wherein the plurality of 2D images comprise a plurality of 2D digitally reconstructed radiograph (DRR) pairs.

49. The machine-readable medium of claim 48, wherein the operations further comprise:

generating a pair of intra-operative images during treatment delivery; and

comparing the pair of intra-operative images with the plurality of DRR pairs to determine the location of the target region during treatment delivery.

50. The machine-readable medium of claim 49, wherein the pair of intra-operative images comprise a pair of x-ray images.

51. The machine-readable medium of claim 42, wherein segmenting the image of the static bony structure comprises:

generating a transversal view of the VOI; and

computing a frontal cut and a sagittal cut of the VOI.