Exact patient positioning by compairing reconstructed x-ray images and linac x-ray images

• US 6,516,046 B1
• Filed: 09/22/2000
• Issued: 02/04/2003
• Est. Priority Date: 11/04/1999
• Status: Expired due to Term

• Current Assignee: Brainlab AG
• Original Assignee: Brainlab AG
• Inventors: Schlossbauer, Cornel, Blumhofer, Andreas, Fröhlich, Stephan
• Primary Examiner(s): Kim, Robert H.
• Assistant Examiner(s): Yun, Jurie
• Application Number:
  US09/668,821
• Time in Patent Office: 865 Days
• Field of Search: 378/65, 378/68, 378/20, 378/205, 378/4, 378/901, 378/98.12
• US Class Current: 378/65
• CPC Class Codes: A61B 2090/101 for stereotaxic radiosurgery
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/70 Means for positioning the patient in relation to the detecting, measuring or recording means
• CPC Class Codes: A61B 6/04 Positioning of patients; Tiltable beds or the like operating tables A61G13/00; operating chairs A61G15/00
• CPC Class Codes: A61N 2005/1061 using an x-ray imaging system having a separate imaging source
• CPC Class Codes: A61N 2005/1062 using virtual X-ray images, e.g. digitally reconstructed radiographs [DRR]
• 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

A method for exact positioning of a patient for radiotherapy or radiosurgery comprising the following steps: a) pre-positioning the patient relative to a linear accelerator, b) producing at least one X-ray image of the patient or one of his/her body parts in the vicinity of the radiation treatment target, c) mapping the X-ray image, d) generating at least one reconstructed image from a three-dimensional set of patient scanning data corresponding to said X-ray image, especially isocentrically, e) superimposing the reconstructed image and the X-ray image, and detecting the positional error electronically or computer-controlled on the basis of specific landmarks in both images, and f) correcting the position of the patient on the basis of the detected positional error.

Claims

1. A method for exact positioning of a patient for radiotherapy or radiotherapy comprising the steps:

a) pre-positioning the patient relative to a linear accelerator,

b) producing at least one X-ray image of the patient or one of his/her body parts in the vicinity of the radiation treatment target,

c) mapping said X-ray image,

d) generating at least one reconstructed image from a three-dimensional set of patient scanning data corresponding to said X-ray image,

e) superimposing said reconstructed image and said X-ray image, and detecting the positional error electronically or computer-controlled on the basis of special landmarks in both images, and

f) correcting the position of the patient on the basis of the detected positional error, and

wherein pre-positioning is carried out by means of a computer-controlled and camera-controlled navigation and tracking system with the aid of artificial marker arrangements on the patient and on the treatment devices.

2. The method as set forth in claim 1, wherein at least two or more X-ray images and corresponding images are generated from different directions, and each are analyzed by comparison.

3. The method as set forth in claim 1, wherein said X-ray image is produced with the radiation source of said linear accelerator.

4. The method as set forth in claim 3, wherein said X-ray image is produced on an X-ray film.

5. The method as set forth in claim 3, wherein said X-ray image and/or said reconstructed image are output on a display.

6. The method as set forth in claim 5, wherein said superimposing of said X-ray image and of said reconstructed image occurs by manual marking and interleaving on a computer display.

7. The method as set forth in claim 3, wherein said X-ray image is produced on amorphous silicon.

8. The method as set forth in claim 1, wherein said X-ray image is produced by one, two or more separate X-ray sources.

9. The method as set forth in claim 1, wherein said X-ray image is produced on an image amplifier or detector.

10. The method as set forth in claim 1, wherein said superimposing of said X-ray image and of said reconstructed image occurs by computer-controlled automatic image fusion.

11. The method as set forth in claim 1, wherein said reconstructed image or images is/are generated as digitally reconstructed radiographs (DRRs), digitally composited radiographs (DCRs), MIP images, or as any two-dimensional image reconstruction from a set of three-dimensional patient scan data.

12. The method as set forth in claim 1, wherein the position of the patient is corrected by shifting a patient table.

13. The method as set forth in claim 1, wherein correcting the position of the patient occurs by operating said table manually.

14. The method as set forth in claim 12, wherein shifting of the patient table is automatically activated and corrected by a computer-controlled and camera-controlled navigation and tracking system with markers on the patient and/or patient table.

15. The method as set forth in claim 1, wherein, in the steps c) and d), a plurality of reconstructed images is generated, which are then superimposed electronically or computer-controlled, and compared to said mapped X-ray image until a reconstructed image is found which corresponds to said X-ray image, with the aid of which said positional error is then detected.

16. The method as set forth in claim 1, wherein the X-ray image is mapped by producing an X-ray image of the patient, detecting the three-dimensional position of the X-ray unit while producing the X-ray image, inserting markers in a predetermined or specific position relative to the X-ray source in the beam path thereof while producing the X-ray image, and calculating, from the geometry of the X-ray unit and from the position of the markers in the X-ray image, the precise three-dimensional imaging situation of the X-ray image.

17. The method as set forth in claim 1, wherein the reconstructed image is generated isocentrically.

18. The method as set forth in claim 1, wherein the marker arrangements include reflecting markers.

19. A method for exact positioning of a patient for radiotherapy or radiotherapy comprising the steps:

a) pre-positioning the patient relative to a linear accelerator,

b) producing at least one X-ray image of the patient or one of his/her body parts in the vicinity of the radiation treatment target,

c) mapping said X-ray image,

d) generating at least one reconstructed image from a three-dimensional set of patient scanning data corresponding to said X-ray image,

e) superimposing said reconstructed image and said X-ray image, and detecting the positional error electronically or computer-controlled on the basis of special landmarks in both images, and

f) correcting the position of the patient on the basis of the detected positional error, and

wherein pre-positioning occurs by means of skin markers on the patient, natural landmarks or laser markings.

20. The method as set forth in claim 19, wherein the reconstructed image is generated isocentrically.

21. The method as set forth in claim 19, wherein at least two or more X-ray images and corresponding images are generated from different directions, and each are analyzed by comparison.

22. The method as set forth in claim 19, wherein said X-ray image is produced with the radiation source of said linear accelerator.

23. The method as set forth in claim 22, wherein said X-ray image is produced on an X-ray film.

24. The method as set forth in claim 22, wherein said X-ray image and/or said reconstructed image are output on a display.

25. The method as set forth in claim 22, wherein said superimposing of said X-ray image and of said reconstructed image occurs by manual marking and interleaving on a computer display.

26. The method as set forth in claim 19, wherein said X-ray image is produced on an image amplifier or detector.

27. The method as set forth in claim 19, wherein said X-ray image is produced on amorphous silicon.

28. The method, as set forth in claim 19, wherein said superimposing of said X-ray image and of said reconstructed image occurs by computer-controlled automatic image fusion.

29. The method as set forth in claim 19, wherein said reconstructed image or images is/are generated as digitally reconstructed radiographs (DRRs), digital composited radiographs (DCRs), MIP images, or as any two-dimensional image reconstruction from a set of three-dimensional patient scan data.

30. The method as set forth in claim 19, wherein the position of the patient is corrected by shifting a patient table.

31. The method as set forth in claim 30, wherein correcting the position of the patient occurs by operating said table manually.

32. The method as set forth in claim 19, wherein, in the steps c) and d), a plurality of reconstructed images is generated, which are then superimposed electronically or computer-controlled, and compared to said mapped X-ray image until a reconstructed image is found which corresponds to said X-ray image, with the aid of which said positional error is then detected.

33. The method asset forth in claim 19, wherein the X-ray image is mapped by producing an X-ray image of the patient, detecting the three-dimensional position of the X-ray unit while producing the X-ray image, inserting markers in a predetermined or specific position relative to the X-ray source in the beam path thereof while producing the X-ray image, and calculating, from the geometry of the X-ray unit and from the position of the markers in the X-ray image, the precise three-dimensional imaging situation of the X-ray image.