Method and Apparatus for Measuring, Verifying, and Displaying Progress of Dose Delivery in Scanned Beam Particle Therapy

• US 20150087885A1
• Filed: 09/22/2014
• Published: 03/26/2015
• Est. Priority Date: 09/22/2013
• Status: Active Grant

• Current Assignee: Pyramid Technical Consultants, Inc.
• Original Assignee: Pyramid Technical Consultants, Inc.
• Inventors: Boisseau, Raymond Paul, Nett, William P., Gordon, John S., Kollipara, Sashidar, Kozlov, Yuriy
• Granted Patent: US 9,731,149 B2
• Time in Patent Office: Days
• US Class Current: 600/1
• CPC Class Codes: A61N 2005/1087 Ions; Protons
• CPC Class Codes: A61N 5/1043 Scanning the radiation beam, e.g. spot scanning or raster scanning
• CPC Class Codes: A61N 5/1067 in real time, i.e. during treatment
• CPC Class Codes: A61N 5/1071 for verifying the dose delivered by the treatment plan

Abstract

The present disclosure is directed to systems and methods for real-time control of a charged particle pencil beam system during therapeutic treatment of a patient. In an aspect, the present disclosure is directed to measuring an actual shape, an actual intensity distribution, and an actual location at isocenter of the charged particle pencil beam. The actual data is compared to model treatment data in real time to determine if a statistically significant variance occurs in which case the charged particle pencil beam can be stopped mid-treatment for correction and/or analysis.

Claims

1. A system for real-time dosage monitoring during therapeutic treatment of a patient, the system comprising:

a pencil beam generator to generate a charged particle pencil beam that travels in a direction parallel to a reference axis, the charged particle beam having an intensity distribution and a shape;

a first detector disposed in a first plane orthogonal to the reference axis and configured to dynamically generate a first output representative of the shape and the intensity distribution of the charged particle pencil beam, the first detector comprising detector elements that define pixels;

a magnetic field generator configured to deflect the charged particle pencil beam, at an angle relative to the reference axis, to a model target location in a patient, wherein the first planar beam detector is disposed between the pencil beam generator and the magnetic field generator;

a second detector disposed in a second plane orthogonal to the reference axis, the second detector configured to generate a second output representative of second coordinates of the charged particle pencil beam in the second plane, wherein the magnetic field generator is disposed between the first detector and the second detector;

a third detector disposed in a third plane orthogonal to the reference axis, the third detector configured to generate a third output representative of third coordinates of the charged particle pencil beam in a third plane, wherein the second detector is disposed between the magnetic field generator and the third detector; and

a controller comprising a processor, the controller configured to receive as inputs the first output, the second output, and the third output and to transmit an intensity control signal to the pencil beam generator and a target location control signal to the magnetic field generator.

2. The system of claim 1 wherein the second detector is a strip detector.

3. The system of claim 1 wherein the third detector is a strip detector.

4. The system of claim 1 wherein the controller is configured to compare target data for a target therapeutic treatment of a spot with actual data acquired during an actual therapeutic treatment of the spot to generate a comparison data.

5. The system of claim 4 wherein the controller is configured to automatically stop the pencil beam generator if the comparison data is greater than a tolerance.

6. The system of claim 5 further wherein the controller is in electrical communication with a display to graphically illustrate the actual data after automatically stopping the pencil beam generator.

7. The system of claim 1 wherein the first detector comprises a polymer layer disposed between a first metal layer and a second metal layer.

8. The system of claim 7 wherein the polymer layer defines a plurality of holes that extend from an upper surface of the polymer layer to a lower surface of the polymer layer.

9. The system of claim 7 wherein the polymer layer has a thickness of between about 10 and about 30 microns.

10. A method for real-time control of a charged particle pencil beam system during therapeutic treatment of a patient, the method comprising:

receiving an image of the charged particle pencil beam during treatment of a target spot;

measuring an actual shape and an actual intensity distribution of the charged particle pencil beam;

determining an actual position of the charged particle pencil beam at an isocenter plane, the actual position corresponding to a location in a pixel of acquired data;

comparing actual data for the target spot with target data for the target spot to form comparison data; and

automatically stopping the therapeutic treatment if the comparison data is greater than a tolerance.

11. The method of claim 10, further comprising:

determining an active region based on the actual position and the shape of the charged particle pencil beam, the active region comprising at least two pixels; and

comparing each pixel in the active region with a corresponding pixel of the target data to form the comparison data.

12. The method of claim 11 further comprising:

increasing the active region by a gamma radius to define a gamma region;

comparing each pixel in the gamma region with a corresponding pixel of the target data to form the comparison data.

13. The method of claim of claim 12 further comprising:

performing a gamma deviation test on each pixel in the gamma region, the gamma deviation test evaluating whether a pixel in the gamma region of actual data is within a gamma tolerance of a corresponding pixel of the target data.

14. A method for real-time control of a charged particle pencil beam system during therapeutic treatment of a patient, the method comprising:

receiving a treatment map for therapeutic treatment of a patient using a charged particle pencil beam system, the treatment map comprising an array of target spots;

generating an acquired matrix from the treatment map, the acquired matrix comprising pixels having target data corresponding to the array of spots, the target data comprising a target position, a target shape, and a target intensity distribution;

removing target data from first pixels corresponding to a first spot from the treatment map;

therapeutically treating a spot in a patient with a charged particle pencil beam;

measuring an acquired image from a pixelated detector disposed between a charged particle pencil beam source and a magnetic field generator, the acquired image including an actual shape and an actual intensity distribution of the charged particle pencil beam;

determining an actual position of the charged particle pencil beam at an isocenter plane;

defining an active region of pixels that receive at least some intensity of the charged particle pencil beam;

updating the first pixels with acquired data for the active region, the acquired data including the actual position, the actual shape, and the actual intensity distribution of the charged particle beam;

comparing the acquired data with target data for each pixel in the active region to generate comparison data; and

automatically stopping the therapeutic treatment if the comparison data is greater than a tolerance.

15. The method of claim 14, further comprising:

extending the active region by a gamma radius to a gamma test region; and

comparing the acquired data with target data for each pixel in the gamma test region to generate comparison data.

16. The method of claim 15 wherein the comparing act comprises performing a gamma deviation test on each pixel in the gamma test region.

17. The method of claim 16 further comprising:

if a pixel does not pass the gamma deviation test, which results in a failed pixel, performing a secondary comparison of the failed pixel.

18. The method of claim 17 further comprising:

defining a search region surrounding the failed pixel by a search radius; and

performing an epsilon deviation test on the search region.

19. The method of claim 18 further comprising stopping the therapeutic treatment if a tolerance number of pixels in a tolerance area fails the epsilon test.

20. The method of claim 19 further comprising stopping the therapeutic treatment if a tolerance number of pixels in a tolerance area fails the gamma test.