Patent ID: 7142635

Claim:
A method of delivering intensity-modulated radiation therapy (IMRT), comprising the steps of: (a) providing an intensity profile for the treatment of a patient, the intensity profile spanning a prescribed field width and comprising a discrete profile having intensity values at each of a plurality of sample points bounded by the prescribed width; (b) comparing the prescribed width to a maximum field width provided by a radiation treatment system; (c) splitting the intensity profile into a plurality of intensity profile portions each having respective widths less than the maximum width if the prescribed width is greater than the maximum width, wherein the splitting includes dividing the prescribed field into a plurality of different profile portion split arrangements and calculating a monitor unit (MU) efficiency for each of the plurality of arrangements, and (d) selecting one of the arrangements from arrangements having an MU efficiency at least 10% greater as compared to splitting based on equal width intensity profile portions for delivery by the system using a leaf sequencing method.