Patent ID: 8663084

Claim:
A method comprising: for an intensity modulated arc therapy treatment plan that includes first and second segments at a same first location along an arc, determining a first desired distribution of the first segment along the arc and a second desired distribution of the second segment along the arc, wherein the first and second desired distributions correspond to locations, of a source moving along the arc, that are different from the first location and that are different from each other, and the intensity modulated arc therapy treatment plan includes a third segment at the first location; determining a desired distribution of the third segment, which includes distributing the third segment according to a determined desired distribution of the third segment in which a spacing between the first and second segments is equal to a spacing between the second and third segments according to the relation: θ S = θ m - 1 - θ m + 1 ( N + 1 ) , wherein θ s is a distance between sub-positions for a beam position m, θ m−1 is a beam position for a first order neighbor on a first side of beam position m, θ m+1 is a beam position for a first order neighbor on a second side of beam position m, and N is a number of segments for beam position, and; distributing, via a computer processor, the first and second segments according to the determined first and second desired distributions.