DOSE-VOLUME KERNEL GENERATION

• US 20110029329A1
• Filed: 03/20/2009
• Published: 02/03/2011
• Est. Priority Date: 04/24/2008
• Status: Active Grant

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Schweizer, Bernd, Goedicke, Andreas
• Granted Patent: US 9,592,408 B2
• Time in Patent Office: Days
• US Class Current: 705/3
• CPC Class Codes: A61N 5/1031 using a specific method of dose optimization
• CPC Class Codes: G16H 20/40 relating to mechanical, radiation or invasive therapies, e.g. surgery, laser therapy, dialysis or acupuncture
• CPC Class Codes: G16H 50/50 for simulation or modelling of medical disorders

Abstract

A radiation planning system includes a dose volume kernel determiner (122) and an expected absorbed dose determiner (124). The dose volume kernel determiner (122) generates a dose volume kernel for each of a plurality of voxels in a dose calculation grid. Each of the dose volume kernels is based on a radial dose distribution and a template function for a particular voxel size. The expected absorbed dose determiner (124) determines an expected absorbed dose distribution for each of the plurality of voxels based on the dose volume kernel.

Claims

1. A radiation treatment planning system comprising:

a dose volume kernel determiner that determines a dose volume kernel for each of a plurality of voxels in a dose calculation grid;

wherein each of the dose volume kernels is based on a radial dose distribution and a template function for a particular voxel size; and

an expected absorbed dose determiner that determines an expected absorbed dose distribution for each of the plurality of voxels based on the dose volume kernel.

2. The system of claim 1, wherein the template function includes geometric information specific to the voxel size and is selected based on the voxel size.

3. The system of claim 1, wherein the radial dose distribution represents absorbed dose due to a point source of a therapy isotope as a function of distance from the point source.

4. The system of claim 1, wherein the template function is a scalable cubic template function of sufficient size for a reference size cubic voxel having equal length sides, wherein the template function is scaled to the voxel size.

5. The system of claim 1, wherein the template function includes a summation of cubic voxel template functions for a cubic voxel that is smaller than a minimum voxel size, wherein the cubic voxel template functions are summed to generate a single template function for a larger voxel of at least the minimum voxel size.

6. The system of claim 5, wherein the larger voxel is not cubic.

7. The system of claim 1, wherein the template function is a summation of three one-dimensional template functions.

8. The system of claim 7, wherein a shape of each of the three one-dimensional template functions is a triangular function.

9. The system of claim 1, wherein the template function is the joint probability density function of three single dimension probability density functions.

10. The system of claim 1, further including a template function determiner that generates the template function based on stochastic sampling.

11. The system of claim 10, wherein the template function represents a normalized frequency of distances between randomly placed start and end points respectively in a source and a target voxel.

12. The system of claim 1, wherein the template function is generated during planning.

13. The system of claim 1, wherein the dose volume kernel determiner determines the dose volume kernel on-demand in that the dose volume kernel is not pre-calculated, but calculated when needed to determine the expected absorbed dose distribution.

14. A method, comprising:

generating a template function for a particular voxel size, wherein the template function includes geometric information specific to the voxel size;

retrieving a radial dose distribution, wherein the radial dose distribution function represents absorbed dose due to a point source of a therapy isotope as a function of distance from the point source; and

generating a dose volume kernel based on the template function and the radial dose distribution.

15. The method of claim 14, further including generating an expected absorbed dose distribution for the therapy isotope based on the dose volume kernel and a residence-time map.

16. The method of claim 14, further including generating the dose volume kernel by sampling the radial dose distribution to a voxel grid for the voxel size using the template function.

17. The method of claim 14, further including generating the template function during radiation therapy planning.

18. The method of claim 14, further including pre-calculating and storing the template function for subsequent radiation therapy planning.

19. The method of claim 14, further including generating the dose volume kernel during radiation therapy planning.

20. The method of claim 14, further including generating the dose volume kernel on-demand, when needed for generating an expected absorbed dose distribution.

21. The method of claim 14, wherein the template function is a cubic template function of sufficient size for a reference size cubic voxel, and further including scaling the template function to the voxel size.

22. The method of claim 15, further including summing a plurality of smaller cubic voxel template functions to generate a single template function for a larger voxel having at least one side with a length greater than the side lengths of the individual cubic voxels.

23. The method of claim 15, further including summing three one-dimensional template functions to generate a three-dimensional template function.

24. The method of claim 15, further including generating the template function through stochastic sampling, wherein the template function is a histogram of distances between randomly placed start and end points respectively in a source and a target voxel.

25. A method, comprising:

prompting a user for a voxel size;

notifying the user when there is no dose volume kernel for the voxel size;

receiving an input indicative of a type of template function to generate from the user;

generating the template function based on the voxel size;

obtaining a radial dose distribution; and

generating a dose volume kernel as a function of the template function and the radial dose distribution for the voxel size.

26. The method of claim 25, further including generating an expected absorbed dose for a therapy isotope based on the generated dose volume kernel.

27. The method of claim 25, further including prompting the user for a number of start and end points used to generate the template function through stochastic sampling.

28. The method of claim 25, further including prompting the user for a threshold error value used to determine a suitable number of start and end points used to generate the template function through stochastic sampling.