Patent ID: 7507975
Filing Date: 2009-03-24
Classification: A61N,G21K

Abstract:
1. A radiation treatment system including: a radiation source which emits radiation energy; a multi-leaf collimator positioned between the radiation source and an isocenter, such that a portion of the radiation energy from the radiation source is transmitted through the multi-leaf collimator to the isocenter; wherein the multi-leaf collimator includes a plurality of leaves, each leaf being movable to allow a selected portion of the radiation energy to be blocked, whereby a shape is defined by the portion of radiation energy which is incident at the isocenter, and the shape is controlled by a positioning of the plurality of leaves; and wherein the multi-leaf collimator includes a first set of leaves which provide for a first area of the shape that has a step resolution length in the range of approximately 3.0 mm or less and wherein the multi-leaf collimator is positioned such that there is a clearance in range approximately 400 mm or greater between the multi-leaf collimator and the isocenter; and wherein the step resolution length corresponds to a length dimension of a dose calculation matrix.