A projection system for effective utilization of ultrasound echogram information in radiation therapy

A system employing an opaque projector mounted on a steel-framed cart was constructed to provide full-scale enlargement of ultrasound echograms for use in radiation therapy planning. Anatomical outlines from the enlarged echograms are traced directly into a minicomputer. Life-sized isodose curves for a selected treatment plan are overlayed on the enlarged echogram to produce a permanent record for treatment field adjustments and retrospective analysis.