Multi-leaf collimator constrained optimization of intensity modulated treatments

• US 6,240,161 B1
• Filed: 09/25/1997
• Issued: 05/29/2001
• Est. Priority Date: 09/25/1997
• Status: Expired due to Term

• Current Assignee: Siemens Medical Solutions USA Incorporated (Siemens AG)
• Original Assignee: Siemens Medical Systems, Inc. (Siemens AG)
• Inventors: Siochi, Ramon Alfredo
• Primary Examiner(s): Church, Craig E.
• Application Number:
  US08/936,299
• Time in Patent Office: 1,342 Days
• Field of Search: 378/65
• US Class Current: 378/65
• CPC Class Codes: A61N 5/1036 Leaf sequencing algorithms
• CPC Class Codes: A61N 5/1042 with spatial modulation of the radiation beam within the treatment head

Abstract

A system and method for radiation therapy delivery. The present invention provides for optimizing radiation delivery by accounting for the physical attributes of a beam shielding device (401) when determining an optimal radiation treatment. These include, for example, constraining the optimization engine with realizable positioning of plates and/or collimator leaves. Thus, an optimal set of fields and intensity levels for those fields are chosen.

Claims

1. A method for delivering radiation from a radiation source to a body, comprising:

specifying a prescription dose volume histogram defining dosages to be delivered to said body;

defining a predetermined number of fields on the body for delivering said dosages;

selecting an initial setting of leaves of a multi-leaf collimator for delimiting each field;

selecting a radiation field intensity for each field;

determining a calculated dose volume histogram corresponding to said openings;

comparing said calculated dose volume histogram with said prescription dose volume histogram; and

delivering radiation according to said calculated dose volume histogram if said calculated dose volume histogram is within a predetermined value of said prescription dose volume histogram.

2. A method according to claim 1, wherein said opening is defined by at least one plate, the plate configured to block radiation from the radiation source.

3. A method according to claim 1, further comprising using an optimization routine to update selected openings.

4. A method according to claim 3, wherein said optimization routine is a simulated annealing routine.

5. A method according to claim 3, further comprising determining an ordering of field delivery once each field is optimized.

6. A system for delivering radiation from a source to an object, comprising:

means for delimiting predetermined radiation fields on said object;

means coupled to said delimiting means for specifying a predetermined number of said fields for delivery; and

means coupled to said specifying means for constraining said delimiting means, said constraining means including means for optimizing delivery of said predetermined radiation fields, said optimizing means using settings of said delimiting means as variables when performing said optimization; and

means for providing radiation according to said optimizing means, said providing means including means for providing radiation according to a calculated dose volume histogram if said calculated does volume histogram is within a predetermined value of a prescription does volume histogram.

7. A system according to claim 6, wherein said delimiting means comprises one or more plates capable of blocking radiation from the radiation source.

8. A system according to claim 7, wherein said delimiting means includes a multi-leaf collimator.

9. A system according to claim 7, wherein said specifying means includes means for specifying one or more settings of said one or more plates.

10. A system according to claim 6, wherein said optimizing means includes means for performing said optimization using simulated annealing.

11. A system according to claim 6, wherein said specifying means includes means for specifying a first dose volume histogram defining dosages to be delivered to said body.

12. A system according to claim 11, wherein said optimizing means includes means for calculating a second dose volume histogram based on said predetermined number of fields and comparing said second dose volume histogram with said first dose volume histogram.

13. A system for delivering radiation from a source to an object, comprising:

means for delimiting predetermined radiation fields on said object;

means coupled to said delimiting means for specifying a predetermined number of said fields for delivery; and

means coupled to said specifying means for constraining said delimiting means, said constraining means including means for optimizing delivery of said predetermined radiation fields;

wherein said specifying means includes means for specifying a first dose volume histogram defining dosages to be delivered to said body;

wherein said optimizing means includes means for calculating a second dose volume histogram based on said predetermined number of fields and comparing said second dose volume histogram with said first dose volume histogram; and

wherein said constraining means includes means for delivering said radiation according to said second dose volume histogram if said second dose volume histogram is within a predetermined value of said first dose volume histogram.

14. A system for delivering radiation from a source to an object, comprising:

a beam shielding device adapted for delimiting predetermined radiation fields on said object;

a controller adapted to specify a predetermined number of said fields for delivery; and

an optimization engine adapted to determine an optimal treatment by using said beam shielding device'"'"'s settings as optimization variables;

wherein said radiation is delivered according to said optimal treatment if a calculated dose volume histogram is within a predetermined value of a prescription dose volume histogram.

15. A system for delivering radiation from a radiation source to a body, said system configured to specify a prescription does volume histogram defining doses to be delivered to said body, said system characterized by:

means for specifying delivery of radiation, said specifying means responsive to said prescription dose volume histogram;

means for determining a calculated dose volume histogram responsive to said specifying means, said calculated dose volume histogram approximating said prescription dose volume histogram; and

means for delivering radiation according to said calculated dose volume histogram if said calculated dose volume histogram is within a predetermined value of said prescription dose volume histogram.

16. A system for delivering radiation from a source to an object, comprising:

a beam shielding device adapted for delimiting predetermined radiation fields on said object;

a controller adapted to specify a predetermined number of said radiation fields for delivery; and

an optimization engine adapted to determine an optimal treatment by using at least one of said predetermined number of radiation fields or beam shielding device settings as optimization variables;

wherein said radiation is delivered according to said optimal treatment if a calculated dose volume histogram is within a predetermined value of a prescription dose volume histogram.

17. A system for delivering radiation from a source to an object, comprising:

a beam shielding device adapted for delimiting predetermined radiation fields on said object;

a controller adapted to specify a predetermined number of said fields for delivery; and

an optimization engine adapted to determine an optimal treatment by using said predetermined number of static fields as optimization variables;

wherein said radiation is delivered according to said optimal treatment if a calculated dose volume histogram is within a predetermined value of a prescription dose volume histogram.