Patent ID: 7180980
Filing Date: 2007-02-20
Classification: A61N

Abstract:
1. A method for optimizing radiation therapy that directly optimizes deliverable rectangular fields that overlap at each beam angle and creates intensity modulations for radiation treatment systems, said method comprising: positioning independent collimator jaws located inside a treatment head of a linear accelerator (LINAC), wherein each jaw can move independently of one another, and wherein the positioning further comprises: selecting a plurality of delivery angles, wherein each of the delivery angles has at least one aperture; assigning collimator angles to each aperture; assigning weights to each aperture; assigning aperture shapes for each of the plurality of delivery angles; defining geometric constraints for a delivery mode and the LINAC; selecting clinical objectives; calculating a dose contribution of each of a plurality of discrete pencil beams, wherein the plurality of discrete pencil beams are delivered at the plurality of delivery angles; calculating a dose distribution and calculating a numeric value of an objective function from the clinical objectives for each of the plurality of delivery angles; altering at least one of the collimator angles, aperture shapes and weights based on a predetermined selection procedure when any of the geometric constraints for the delivery mode are violated; calculating the dose distribution resulting from altering at least one of the collimator angles, aperture shapes and weights based on the predetermined selection procedure; determining whether the geometric constraints for delivery are met; calculating the objective function based on the dose distribution; determining whether to one of accept or reject a change in parameters based on at least one optimization method; and outputting resulting aperture shapes, weights and dose distribution for optimized radiation therapy when the change in parameters is accepted.