Software for linear and non-linear optimization in external radiotherapy.

The study presents a set of programs designed to determine optimum dose distribution either by calculation of beam intensities and field width (in linear programming) or, in addition, by calculation of beam geometry (non-linear optimization). Various optimization criteria can be selected: homogeneity, concentration on target, entire dose in a sensitive area. The optimization method used is the gradient projection method, and doses are calculated by Cunningham formulae. The article describes the program operating modes, the main subroutines and their functions and specifications, and outlines an example.