Variable feathering field splitting for intensity modulated fields of large size
View Patent ↗A method and associated system 300 for delivering intensity-modulated radiation therapy (IMRT) uses variable feathering field splitting for intensity modulated fields of large size. A processor controls a beam-shaping device that splits the radiation beam into a plurality of radiation fields delivered to a patient. The processor in cooperation with the beam-shaping device implements a variable feathering method which includes providing an intensity matrix for the treatment of a patient, the intensity matrix having a plurality of rows and columns for spanning a prescribed radiation field including a prescribed field width. The prescribed width is compared to a maximum field width provided by the radiation treatment system. The intensity matrix is split into a plurality of spatially overlapping intensity submatrices by variably feathering the intensity matrix when the prescribed width exceeds the maximum field width, Radiotherapy is then provided to the patient using a leaf sequencing method to generate the submatrices.
1. A method of delivering intensity-modulated radiation therapy (IMRT) using variable feathering field splitting for intensity modulated fields of large size, comprising the steps of:
(a) providing an intensity matrix for the treatment of a patient, said intensity matrix having a plurality of rows and columns for spanning a prescribed radiation field including a prescribed field width;
(b) comparing said prescribed width to a maximum field width provided by a radiation treatment system;
(c) splitting said intensity matrix into a plurality of spatially overlapping intensity submatrices when said prescribed width exceeds said maximum field width, wherein said splitting comprises variably feathering said intensity matrix, and
(d) providing radiotherapy to said patient using a leaf sequencing method applied to a beam-shaping device to generate said submatrices.
2. The method of claim 1 , wherein said variably feathering comprises feathering along non-constant columns of said intensity matrix.
3. The method of claim 1 , wherein said splitting is implemented by minimizing total therapy time.
4. The method of claim 1 , wherein said splitting is implemented by minimizing a total number of leaf sequences in delivering a predetermined dosage to said patient.
5. The method of claim 1 , wherein said beam-shaping device is a segmented multi-leaf collimator.
6. The method of claim 1 , wherein said beam-shaping device is a dynamic multi-leaf collimator.
7. A system for delivering radiation treatment to patients, the system comprising:
a radiation source for providing a radiation beam;
a beam-shaping device interposed between the radiation source and a patient for shaping the radiation beam, the beam-shaping device having a plurality of leaves that cooperatively form leaf sequences for shaping the radiation beam, and
a processor in communication with the beam-shaping device, said processor acting on an intensity matrix for the treatment of a patient, said intensity matrix having a plurality of rows and columns for spanning a prescribed radiation field including a prescribed field width, said processor causing the beam-shaping device to split the radiation beam into a plurality of spatially overlapping intensity submatrices that are delivered to said patient when said prescribed width exceeds a maximum field width provided by said system, wherein said splitting comprises variably feathering said intensity matrix.
8. The system of claim 7 , wherein the beam-shaping device is a segmented multi-leaf collimator.
9. The system of claim 7 , wherein the beam-shaping device is a dynamic multi-leaf collimator.