Varian Medical Systems Inc
Method and apparatus to employ a multi-layer multi-leaf collimator when administering a radiation therapy treatment

Abstract:

A control circuit administers a radiation treatment plan that specifies a planned total radiation dose for a radiation treatment session for a given patient by modulating a radiation beam with at least one high-resolution aperture that is formed using one of a plurality of linearly-sequential high-resolution aperture possibilities. By one approach the foregoing comprises modulating the radiation beam using at least substantially only high-resolution apertures that are formed using a plurality of the linearly-sequential high-resolution aperture possibilities. In some cases the foregoing can comprise administering the radiation treatment plan using at least two separate radiation exposures for only a single treatment field, in which case, by one approach, each of the separate radiation exposures for the single treatment field can comprise modulating the radiation beam using at least substantially only high-resolution apertures.