Patent ID: 8712011

Claim:
A method for planning a radiation treatment for delivery by a radiotherapy apparatus, the method comprising: defining at least one set of imaging conditions for imaging with an imaging beam, each set of imaging conditions comprising at least a beam angle and a beam shape for exposing at least one imaging volume of interest to radiation; establishing a plan for a therapeutic radiation treatment to be delivered by a treatment beam different from the imaging beam, the plan comprising apertures for a plurality of beam angles; estimating a volumetric radiation dose that would result from the at least one set of imaging conditions using first data characterizing the imaging beam; estimating a volumetric radiation dose that would result from delivering the plan for a therapeutic radiation treatment using second data characterizing the treatment beam; optimizing the apertures to deliver a desired radiation dose to a target region of a subject while maintaining radiation dose to tissues outside of the target region below one or more thresholds while taking into account the estimated volumetric radiation dose for the at least one set of imaging conditions at least in a selected region outside of the target region.