Radiobiological Considerations in Gynaecological Radiotherapy

Abstract

Gynaecological radiotherapy normally involves the use of various combinations of external beam irradiation and brachytherapy, the latter component of which may be fractionated, and delivered at low, medium or high dose rate. A wide variety of treatment techniques have evolved and in recent years there has been a move towards the use of remote-controlled afterloading systems with which to deliver the brachytherapy component. Gynaecological radiotherapy is therefore a subject of major radiobiological significance, but analytically is complicated by the fact that irradiated volumes can vary considerably, and by the presence of the unavoidable dose gradients associated with all types of brachytherapy. Nevertheless, there have emerged some fairly clear radiobiological principles which, although not yet capable of being used for the routine optimisation of gynaecological radiotherapy, can at least throw light on the identification of relatively “safe” techniques.