RADICAL RADIOTHERAPY FOR CARCINOMA OF THE UTERINE CERVIX USING EXTERNAL-BEAM RADIOTHERAPY AND A SINGLE LINE SOURCE BRACHYTHERAPY TECHNIQUE - THE CLATTERBRIDGE TECHNIQUE

At the Clatterbridge Centre for Oncology, a single line source brachyt herapy technique using the Selectron (Nucletron) low dose rate remote afterloading equipment has been developed for use in conjunction with homogenous whole pelvis external beam radiotherapy in the radical trea tment of carcinoma of the cervix. The technique incorporates several m odifications aimed at reducing treatment related morbidity while maint aining satisfactory local tumour control and cure rates. A flexible do se prescription system has been devised to allow individualization of the brachytherapy isodose distribution according to the clinical findi ngs and the estimated normal tissue doses. Modifications of source loa ding distributions are carried out to limit the point ''A'' dose rate to a narrow range to take into account the dose rate effect on the ris k of complications. Source loading distributions are also modified acc ording to the estimated normal tissue doses in order to respect normal tissue tolerance. This paper describes the technique and its underlyi ng principles.