Patent ID: 6577707
Filing Date: 2003-06-10
Classification: A61N,G21K

Abstract:
A method for defining an extended field area of an intensity map for use in delivering radiation from a radiation source to an object with a multi-leaf collimator having a plurality of leaves operable to travel in a first direction and rotatable such that the leaves are operable to travel in a second direction extending generally orthogonal to said first direction, the method comprising:defining a central square area having dimensions approximately equal to two times an over travel margin of the multi-leaf collimator; and defining four edge margins each extending from a side of said central square and having dimensions approximately equal to two times an over travel margin of the multi-leaf collimator along an edge adjacent to said central square, and half the number of leaves within the multi-leaf collimator times leaf width minus half the dimension of the central square; wherein said central square and four edge margins define a field area for an intensity map deliverable with the multi-leaf collimator in two positions such that leaves travel in said first and second directions.