Real-time in vivo radiation dosimetry using scintillation detector

• US 9,907,980 B2
• Filed: 04/14/2014
• Issued: 03/06/2018
• Est. Priority Date: 01/08/2009
• Status: Active Grant

• Current Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Original Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Inventors: Beddar, A. Sam, Briere, Tina Marie, Archambault, Louis
• Primary Examiner(s): Porta, David
• Assistant Examiner(s): Malevic, Djura
• Application Number:
  US14/251,796
• Publication Number:
  US 20140221724A1
• Time in Patent Office: 1,422 Days
• Field of Search: 25037011, 250362, 250368, 600407, 600431, 600436
• CPC Class Codes: A61N 2005/1072 taking into account movement of the target
• CPC Class Codes: A61N 5/1048 Monitoring, verifying, controlling systems and methods
• CPC Class Codes: A61N 5/1071 for verifying the dose delivered by the treatment plan
• CPC Class Codes: G01T 1/023 Scintillation dose-rate meters
• CPC Class Codes: G01T 1/161 Applications in the field of nuclear medicine, e.g. in vivo counting apparatus for radiation diagnosis A61B6/00

Abstract

Apparatus and methods for measuring radiation levels in vivo in real time. Apparatus and methods include a scintillating material coupled to a retention member.

Claims

1. A method of measuring radiation levels in real time during radiation therapy of a prostate, the method comprising:

(a) inserting a rectal balloon into a rectum of a male patient having prostate cancer;

(i) said rectal balloon having an external shape that conforms to a prostate, wherein said rectal balloon has a cross-section that is generally elliptical having a greater width than height when viewed from a first end of said rectal balloon, and wherein said rectal balloon has an indentation along its width;

(ii) said rectal balloon coupled to a dosimeter comprising a plastic scintillating material coupled to an optical guide;

(iii) said indentation of said rectal balloon extending axially from the first end of said rectal balloon; and

(iv) said indentation extending inward toward said dosimeter;

(b) inflating said rectal balloon;

(c) coupling said dosimeter to a photodetector coupled to a data analyzer;

(d) initiating a radiation therapy of said prostate;

(e) calculating a level of radiation at said prostate based on the amount of light detected by said photodetector; and

(f) stopping said radiation therapy when said calculated level of radiation is equal to a predetermined level of radiation.

2. The method of claim 1, wherein said balloon comprises a channel and said dosimeter is inside said channel.

3. The method of claim 2, wherein said rectal balloon comprises one or more radiopaque markers, the method further comprising:

(a) visualizing said one or more radiopaque markers; and

(b) positioning said rectal balloon based on said visualization so that said rectal balloon is in a desired location.

4. The method of claim 2, wherein said rectal balloon comprises radiopaque markers asymmetrically arranged on said rectal balloon, the method further comprising:

(a) determining the position of said radiopaque markers; and

(b) positioning said rectal balloon until said rectal balloon is in a desired location based on said position of said radiopaque markers.

5. The method of claim 1 wherein said radiation therapy is radiation beam therapy.

6. The method of claim 1, wherein said rectal balloon comprises one or more radiopaque markers, the method further comprising:

(a) visualizing said one or more radiopaque markers; and

(b) positioning said rectal balloon based on said visualization so that said rectal balloon is in a desired location.

7. A device for in vivo real time dosimetry during radiation therapy, said device comprising:

(a) an inflatable rectal balloon fluidly coupled to a conduit for inflating said balloon;

(b) said balloon having an external shape that conforms to a prostate, wherein said rectal balloon has a cross-section that is generally elliptical having a greater width than height when viewed from a first end of said rectal balloon, and has an indentation along its width;

(c) said rectal balloon comprising a channel thereon, said channel containing a real time dosimeter;

(d) said indentation of said rectal balloon extending axially from the first end of said rectal balloon; and

(e) said indentation extending inward toward the real time dosimeter;

(f) said real time dosimeter comprising a water equivalent plastic scintillator coupled to an optical fiber; and

(g) wherein said real time dosimeter can monitor an in vivo dose of radiotherapy beams or brachytherapy in real time.

8. The rectal balloon of claim 7, said rectal balloon further comprising an indentation when inflated to conform said rectal balloon to a prostate when in use.

9. The rectal balloon of claim 7, wherein said real-time dosimeter comprises a plurality of plastic scintillators optically coupled to a plurality of optical fibers and wherein one or more of the optical fibers extend different lengths along said rectal balloon.

10. The rectal balloon of claim 7, wherein a plurality of channels contain a plurality of real-time dosimeters.

11. The rectal balloon of claim 7, further comprising one or more radiopaque markers on said rectal balloon.

12. The rectal balloon of claim 7, further comprising one or more radiopaque markers arranged asymmetrically on said rectal balloon.

13. The rectal balloon of claim 7, wherein said real time dosimeter is configured to be coupled to a photodetector.