Face mould for administering radiotherapy, c 1965.

Pinpoint accuracy in positioning the treatment head in relation to the tumour over several therapy sesions is esential in radiotherapy. A perspex cast of the patient's face, made from an initial plaster cast, holds the head in the same position and marks the region being treated. This example was used with a Betatron particle accelerator at St Luke's Hospital, Guildford, England.