Radiation hazards during cobalt 60 plaque therapy for choroidal melanoma.

Prompted by the concerns of the staff and patients, radiation hazards from Cobalt 60 (Co 60) plaque therapy for choroidal melanoma were recently assessed when two patients were concurrently treated at Christchurch Hospital. The risks from radiation to the attending medical staff, nursing personnel from the operating theatre and ward, and the patients' visitors were investigated. The radiation dose for all staff and visitors involved with the two patients was found to be well below the recommended weekly limits set by the International Commission on Radiological Protection. Our department code of practice to minimise radiation hazard during plaque therapy has been revised.