METHOD FOR SELECTING BEAM ORIENTATIONS IN INTENSITY MODULATED RADIATION THERAPY

A method for selecting an orientation of a treatment beam for intensity modulated radiation therapy based on analysis performed on a model of a patient geometry prior to the actual treatment includes a planning target volume (PTV) and the structures at risk. The method calls for assigning a tolerance parameter to the structures at risk, subdividing the treatment beam into beamlets, selecting a treatment parameter and selecting a set of orientations for the treatment beam and deriving a score for each of the orientations by weighting each of the beamlets so as to maximize the treatment parameter in the PTV while not exceeding the tolerance parameter in the structures at risk at each orientation. The derived scores are used to construct a scoring function to aid in the selection of one or more treatment beam orientations to be used during the actual intensity modulated radiation therapy.