AN AID TO RADIATION-THERAPY SIMULATION

We have mounted a transmission liquid crystal display unit on the head of a radiotherapy simulator and projected, using the field light, a d igitized fluoroscopic image with treatment prescription overlay. It is suggested that this approach (i) can aid visualization on the patient of complex field borders including those defined by multileaf collima tors; (ii) could play a role in computed tomography or magnetic resona nce based treatment planning and (iii) contributes to configuring non- coplanar beams.