Patent ID: 8615068

Claim:
A method for producing a radiation therapy plan for intensity modulated arc therapy, in which a radiation source delivers radiation to a target volume in a subject while the radiation source traverses a plurality of delivery angles in at least one arc, the method comprising the steps of: a) generating a plurality of segmentations, each segmentation defining an intensity of radiation to be delivered from the radiation source to the target volume in the subject at one of the plurality of delivery angles of the radiation source; b) ordering apertures within each of the plurality of segmentations generated in step a) by minimizing total leaf movement between segmentations corresponding to adjacent delivery angles, and thereby calculating corresponding minimum total leaf movement values between such segmentations; c) selecting from the plurality of segmentations, a segmentation to be used at each of the plurality of delivery angles of the radiation source using the minimum total leaf movement values calculated in step b) and a network model having nodes that each correspond to both the plurality of delivery angles and the plurality of segmentations; d) generating apertures from the segmentations selected in step c) by minimizing total leaf movement relative to the segmentations selected in step c) subject to a maximum leaf movement constraint; and e) modifying the apertures generated in step d) by reducing segmentation errors using a network model having nodes corresponding to rows of each aperture in the segmentations generated in step d) and positions of leaves in each row of each aperture to modify one aperture at a time.