Improved method for the design of tissue compensators

A program, WBEAM, is described which calculates dose distributions in planes perpendicular to the beam axis, taking into account both field shape and patient contour. WBEAM can be used to design compensators which when placed in the beam will produce uniform dose distributions in the plane of calculation. The program was tested in three different situations: a 30 x 30 cm field with a flat contour, a "mantle" field with a flat contour, a "mantle" field with a human-like contour. The program performs as designed: the dose distributions are accurate, and the compensators flatten the radiation beams to the specified limits.