Patent ID: 8325878

Claim:
A system for radiation therapy comprising a radiation planning system, wherein said radiation planning system comprises a parallel processor adapted to receive input information concerning a body having an intended radiation treatment region and to output information for providing radiation treatment to said intended radiation treatment region of said body, wherein said parallel processor is adapted to perform a plurality of reverse ray tracing calculations based on said input information concerning said body in determining said output information for providing radiation treatment, each of said plurality of reverse ray tracing calculations comprising: calculating a first physical property corresponding to a first sub-region of said intended radiation treatment region of said body that is intersected by a ray traced between a source position and said intended radiation treatment region; and calculating, subsequent to the first-mentioned calculating, a second physical property corresponding to a second sub-region of said intended radiation treatment region that is intersected by said ray at a location closer to said source position than is said first sub-region.