A New System of Field Shaping for External-Beam Radiation Therapy

Abstract

A new system for designing and shaping teletherapy treatment fields to any form or size is described. A low-melting alloy, Lipowitz's metal, is cast in a styrofoam form which was cut with a hot-wire device. A one-piece assembly is produced for each patient. In daily application the block assembly is simply and quickly indexed into correct position in the head of the therapy unit and is held securely regardless of the head angulation. Materials are salvaged and reused upon completion of the treatment course. The system has been shown to be accurate and reproducible.