Calibrating a positron emission tomography scanner

• US 7,679,049 B2
• Filed: 04/28/2008
• Issued: 03/16/2010
• Est. Priority Date: 05/02/2007
• Status: Active Grant

• Current Assignee: Varian Medical Systems Particle Therapy GmbH & Company KG (Siemens AG)
• Original Assignee: Siemens AG
• Inventors: Rietzel, Eike
• Primary Examiner(s): Porta; David P
• Assistant Examiner(s): Malevic; Djura
• Application Number:
  US12/110,978
• Publication Number:
  US 20080272284A1
• Time in Patent Office: 687 Days
• Field of Search: 250/252.1, 250/363.04
• US Class Current: 250/252.1
• CPC Class Codes: A61B 6/583 using calibration phantoms
• CPC Class Codes: A61N 2005/1052 using positron emission tomography [PET] single photon emission computer tomography [SPECT] imaging
• CPC Class Codes: A61N 2005/1076 using a dummy object placed in the radiation field, e.g. phantom
• CPC Class Codes: G01T 1/169 Exploration, location of contaminated surface areas
• 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 1/2985 In depth localisation, e.g. using positron emitters; Tomographic imaging (longitudinal and transverse section imaging; apparatus for radiation diagnosis sequentially in different planes, steroscopic radiation diagnosis); using external radiation sources A61B6/02

Abstract

A method for calibrating a positron emission tomography scanner of a radiation therapy device is provided. The method includes applying at least one defined radiation dose in a sample body; measuring the activity generated by the radiation dose using the positron emission tomography scanner; and calibrating the positron emission tomography scanner based on the measured activity.

Claims

1. A method for calibrating a positron emission tomography scanner of a radiation therapy device, the method comprising:

applying, using a radiotherapy device, at least one defined radiation dose in a sample body to induce a defined activity in the sample body, the at least one defined radiation dose being applied by irradiating the sample body with a treatment radiation beam of the radiotherapy device;

measuring the activity generated by the at least one defined radiation dose with the positron emission tomography scanner; and

calibrating the positron emission tomography scanner as a function of the measured activity.

2. The method as defined by claim 1, wherein applying at least one defined radiation dose includes applying the at least one defined radiation dose at a predetermined site in a treatment chamber and/or in the sample body.

3. The method as defined by claim 2,

wherein applying at least one defined radiation dose includes applying a plurality of different radiation doses in the sample body;

wherein measuring the activity generated by the at least one defined radiation dose includes measuring the activities generated by the plurality of different radiation doses with the positron emission tomography scanner;

wherein calibrating the positron emission tomography scanner includes calibrating the positron emission tomography scanner as a function of the measured activities.

4. The method as defined by claim 3, wherein the plurality of different radiation doses are different in dose, application site, application time, or combinations thereof.

5. The method as defined by claim 2, wherein calibrating comprises calibrating a response performance of detector elements of the positron emission tomography scanner, a local resolution, a local coding of the positron emission tomography scanner, or combinations thereof as a function of the measured activity.

6. The method as defined by claim 2, wherein the sample body is a polymethylmethacrylate phantom.

7. The method as defined by claim 2, wherein the radiation therapy device is a particle therapy system, with which at least one defined particle dose is applied as a defined radiation dose in the sample body.

8. The method as defined by claim 1, wherein applying at least one defined radiation dose includes applying a plurality of different radiation doses in the sample body.

9. The method as defined by claim 8, wherein the plurality of different radiation doses are different in dose, application site, or application time, or combinations thereof.

10. The method as defined by claim 1, wherein calibrating comprises calibrating a response performance of detector elements of the positron emission tomography scanner, a local resolution, a local coding of the positron emission tomography scanner, or combinations thereof as a function of the measured activity.

11. The method as defined by claim 1, wherein the sample body is a polymethylmethacrylate phantom.

12. The method as defined by claim 1, wherein the radiation therapy device is a particle therapy system, with which at least one defined particle dose is applied as one of the at least one defined radiation dose in the sample body.

13. The method as defined by claim 1,

wherein applying at least one defined radiation dose includes applying a plurality of different radiation doses in the sample body;

wherein measuring the activity generated by the at least one defined radiation dose includes measuring the activities generated by the plurality of different radiation doses with the positron emission tomography scanner;

wherein calibrating the positron emission tomography scanner includes calibrating the positron emission tomography scanner as a function of the measured activities.

14. The method as defined by claim 1, wherein applying at least one radiation dose includes distributing the at least one defined radiation dose in accordance with a predetermined three-dimensional radiation pattern.

15. The method as defined by claim 14, wherein measuring includes obtaining a spatial distribution of the induced activity using the predetermined three-dimensional radiation pattern.

16. The method as defined by claim 1, wherein applying includes successively applying defined radiation doses that differ in intensity.

17. The method as defined by claim 1, wherein calibrating the positron emission tomography scanner includes calibrating the positron emission tomography scanner as a function of the measured activity and a known activity known from the defined at least one radiation dose, the measured activity being correlated with the known activity.

18. A radiation therapy device, comprising:

a radiation source that is operable to apply at least one defined radiation dose in a sample body, the at least one defined radiation dose being applied by irradiating the sample body with a treatment radiation beam, the defined radiation dose inducing a defined activity in the sample body;

a positron emission tomography scanner in at least one treatment chamber, the positron emission tomography scanner being operable to measure radiation activity generated by the at least on defined radiation dose; and

a control unit that is operable to calibrate the positron emission tomography scanner based on measured radiation activity.

19. The radiation therapy device as claimed in claim 18, wherein the radiation source is a particle source.

20. The radiation therapy device as claimed in claim 18, wherein the at least one defined radiation dose is a plurality of different dosages.