METHOD FOR ADAPTING FRACTIONATION OF A RADIATION THERAPY DOSE

• US 20090110145A1
• Filed: 10/27/2008
• Published: 04/30/2009
• Est. Priority Date: 10/25/2007
• Status: Active Grant

• Current Assignee: TomoTherapy Incorporated (Accuray Incorporated)
• Original Assignee: TomoTherapy Incorporated (Accuray Incorporated)
• Inventors: Ruchala, Kenneth J., Lu, Weiguo, Chen, Mingli, Chen, Quan, Olivera, Gustavo H.
• Granted Patent: US 8,222,616 B2
• Time in Patent Office: Days
• US Class Current: 378/65
• CPC Class Codes: A61B 34/10 Computer-aided planning, simulation or modelling of surgical operations
• CPC Class Codes: A61N 2005/1061 using an x-ray imaging system having a separate imaging source
• CPC Class Codes: A61N 5/103 Treatment planning systems
• CPC Class Codes: A61N 5/1038 taking into account previously administered plans applied to the same patient, i.e. adaptive radiotherapy

Abstract

A system and method of adapting a radiation therapy treatment plan for a patient by varying the fraction size delivered to the patient on any individual day, based at least partially on the use of daily patient registration (i.e., taking images of the patient before each fraction is delivered to see the position and size of the tumor on that day). The fraction size can be dynamically altered based upon the biology of the tumor.

Claims

1. A method of adapting a treatment plan, the method comprising:

preparing a treatment plan for a patient, the treatment plan including multiple treatment fractions each having a planned radiation dose to be delivered to the patient;

identifying a position of a first structure relative to a second structure prior to delivering each one of the fractions,

prior to delivering the present treatment fraction, adjusting the planned radiation dose to be delivered to the patient for the present treatment fraction based on the position of the first structure relative to the second structure without replanning the treatment plan; and

delivering the adjusted planned radiation dose to the patient.

2. The method of claim 1, wherein the first structure includes a tumor.

3. The method of claim 1, wherein the second structure includes an organ at risk.

4. The method of claim 1, wherein adjusting the treatment plan is based upon the planned dose that would be delivered to the patient during the one treatment fraction.

5. The method of claim 4, wherein adjusting the treatment plan is based upon a comparison of an adjusted fraction dose to the planned dose to be delivered.

6. The method of claim 5, further comprising incorporating the cumulative dose delivered to date.

7. The method of claim 5, further comprising incorporating planned doses for subsequent fractions.

8. The method of claim 1, wherein identifying the position of a first structure relative to a second structure includes using internal landmarks.

9. The method of claim 8, wherein the internal landmarks includes fiducial markers.

10. The method of claim 1, wherein identifying the position of a first structure relative to a second structure includes using surrogates.

11. The method of claim 1, wherein identifying the position of a first structure relative to a second structure includes acquiring an image of the patient.

12. The method of claim 11, further comprising analyzing the acquired image to obtain biological or anatomical information about the patient.

13. The method of claim 1, wherein preparing the treatment plan having multiple treatment fractions includes calculating a total planned delivered dose to the patient.

14. The method of claim 13, wherein calculating the total planned delivered dose includes calculating a total planned dose to be delivered to a tumor volume and a total planned dose to be delivered to a non-tumorous structure that is located in physical proximity to the tumor volume.

15. The method of claim 14, wherein increasing or decreasing the dose to be delivered during the treatment fraction based upon the acquired information reduces the total planned dose to be delivered to the non-tumorous structure while allowing the total planned dose to be delivered to the tumor volume.

16. The method of claim 1, wherein preparing the treatment plan includes calculating a total biological effect to the patient, and wherein the total biological effect includes tumor control probability.

17. A method of treating a patient with radiation therapy using a plurality of fractions to deliver a total planned radiation dose to a tumor volume that has a sensitive structure in physical proximity to a tumor volume, the method comprising:

preparing a treatment plan for a patient, the treatment plan including multiple treatment fractions each having a planned delivered dose;

acquiring an image of the patient;

using the acquired information to adjust the dose to be delivered for a given treatment fraction; and

delivering radiation to the patient according to the treatment plan such that the adjusted dose is delivered to the patient.

18. The method of claim 17, wherein information about the patient is obtained from the acquired image and includes at least one of tumor volume size, tumor volume position, and sensitive structure position.

19. The method of claim 17, wherein using the acquired image to adjust the dose to be delivered for a given fraction includes increasing the planned delivered dose for the fraction.

20. The method of claim 17, wherein using the acquired image to adjust the dose to be delivered for a given fraction includes decreasing the planned delivered dose for the fraction.

21. The method of claim 17, wherein adjusting the dose to be delivered for a fraction reduces the total planned radiation dose delivered to the sensitive structure while maintaining the total planned radiation dose delivered to the tumor volume.

22. The method of claim 17, wherein adjusting the dose to be delivered for a given fraction reduces the total number of fractions delivered to the patient while maintaining the total planned radiation dose delivered to the tumor volume.

23. The method of claim 17, wherein adjusting the dose to be delivered for a fraction reduces the total biological effect to the sensitive structure while maintaining the same anticipated biological effect to the tumor volume.

24. The method of claim 17, wherein adjusting the dose to be delivered for a given fraction includes an optimization procedure.

25. The method of claim 24, wherein adjusting the dose to be delivered using the optimization procedure incorporates the cumulative dose delivered and the biological effect to the patient to date.

26. The method of claim 24, wherein adjusting the dose to be delivered using the optimization procedure incorporates the expected future dose to be delivered and the biological effect to the patient.

27. The method of claim 17, wherein using the acquired information to adjust the dose to be delivered for a given treatment fraction is done without doing a dose calculation.

28. The method of claim 17, wherein using the acquired information to adjust the dose to be delivered for a given treatment fraction includes using an on-line dose calculation to evaluate how much to adjust the dose to be delivered for that given fraction.

29. The method of claim 17, wherein using the acquired information to adjust the dose to be delivered for a given treatment fraction includes utilizing the cumulative dose delivered to date.

30. The method of claim 17, wherein using the acquired information to adjust the dose to be delivered for a given treatment fraction uses an extrapolation of what the patient'"'"'s anatomy is expected to do on subsequent days for subsequent treatment fractions.

31. The method of claim 17, wherein using the acquired information to adjust the dose to be delivered for a given treatment fraction incorporates a biological model for dose accumulation and the effect of varying fraction sizes on the outcomes to the patient.

32. The method of claim 17, wherein using the acquired information to adjust the dose to be delivered for a given treatment fraction includes using deformation.

33. The method of claim 17, wherein using the acquired information to adjust the dose to be delivered for a given treatment fraction is done in tandem with another adaptive strategy.

34. The method of claim 33, wherein the other adaptive strategy includes one of altering the plan and selecting an appropriate plan from a previously prepared library of plans.

35. The method of claim 17, wherein using the acquired information to adjust the dose to be delivered for a given treatment fraction incorporates qualitative or quantitative assessments of the biological effect on the patient.

36. The method of claim 35, wherein the biological effect on the patient includes at least one of tumor regression, patient tolerance, and patient side effects.

37. A radiation therapy treatment system for adapting a treatment plan, the radiation therapy treatment system comprising:

a computer processor; and

a software program stored in a computer readable medium accessible by the computer processor, the software being operable to

generate a treatment plan for a patient, the treatment plan including multiple treatment fractions each having an associated planned delivered dose to be delivered to the patient,

identify a position of a first structure relative to a second structure prior to delivery of each one of the fractions,

prior to delivery of the present treatment fraction, adjust the planned radiation dose to be delivered to the patient for the present treatment fraction based on the position of the first structure relative to the second structure without the treatment plan being replanned, and

deliver the adjusted planned radiation dose to the patient.

38. A computer program embodied by a computer readable medium capable of being executed by a computer, the computer program for use in a radiation therapy treatment system, the computer program comprising:

a treatment plan module operable to generate a treatment plan for a patient, the treatment plan including multiple treatment fractions each having an associated planned delivered dose to be delivered to the patient;

a patient position module operable to identify a position of a first structure relative to a second structure prior to delivery of each one of the fractions;

a fraction modification module operable to, prior to delivery of the present treatment fraction, adjust the planned radiation dose to be delivered to the patient for the present treatment fraction based on the position of the first structure relative to the second structure without the treatment plan being replanned; and

a treatment delivery module operable to deliver the adjusted planned radiation dose to the patient.