Patent ID: 7162008
Filing Date: 2007-01-09
Classification: A61N

Abstract:
1. A method for planning radiation treatment of a target area, wherein a radiation source is disposed on a gantry that is movable along multiple arcs, and a collimator is operable to form multiple apertures for passing a radiation beam produced by said radiation source, said method comprising: designating geometric constraints for the collimator; assigning an initial aperture configuration for passing the radiation beam based on the designated geometric constraints of the collimator comprising selecting a number of delivery angles for the radiation beam towards the target area and a number of apertures through which the radiation beam is directed; and selecting a number and range of arcs for the gantry; calculating a radiation dose distribution of initial radiation to a target area of a patient based on the initial aperture configuration; evaluating the initial radiation to the patient against an objective function; altering the initial aperture configuration based on the geometric constraints of the collimator; calculating an altered radiation dose distribution to the patient based on the altered aperture configuration and re-evaluating the altered radiation output against the objective function; re-altering the altered aperture configuration; re-calculating the altered radiation dose distribution to the patient and re-evaluating the altered radiation output for the re-altered aperture configuration until the objective function is satisfied, wherein the objective function scores the radiation treatment plan quality and is a function of the altered radiation dose distribution at a given iteration, and wherein an aperture configuration comprises a plurality of aperture shapes delivered from the selected delivery angles, selected number of apertures through which the radiation beam is directed, and the selected number and range of arcs for the gantry to the target area and wherein designating initial constraints for the collimator occurs prior to calculating the initial radiation dose distribution.