Afterloading

In view of the likely revision of the Code of Practice for radiation safety for radiotherapy departments, a review of existing safety precautions is undertaken. Most of the dose to radiographers comes from unsealed sources (e.g. 131I) and the use of small sealed sources in the form of intracavitory insertions, implants and moulds. Small sealed sources are dealt with in particular. Factors considered in minimising the dose to operational personnel are shielding, distance, time and manual or automatic afterloading of the radiation source. A detailed discussion is given on various commercial afterloading devices and operational experience of treating carcinoma of the cervix at Glasgow is reported. It is concluded that manual afterloading does not protect the staff at greatest risk (usually nurses) and that automatic afterloading machines appear to be the ideal solution. (U.K.)