Extended field area defining method for radio therapy, involves defining central square area and four margins to characterize field area for intensity map that is deliverable within multi-leaf collimator

摘要

The method involves defining a central square area with dimensions approximately equal to two times an over travel margin of a multi-leaf collimator. Four edge margins are defined along an edge adjacent to the central square area. The central square and four edge margins define a field area for an intensity map that is deliverable within the collimator in two positions such that leaves travel in two directions. An Independent claim is also included for a system for delivering an intensity map for use in delivering radiation from a radiation source to an object using a multi-leaf collimator.