Prediction of severe late complications in fractionated, high dose-rate brachytherapy in gynecological applications.

The pertinence of different points and volumes, proposed for reporting and prediction of complications in classical low dose-rate brachytherapy, was tested for high dose-rate, fractionated gynecological applications. A group of patients experiencing complications (especially rectal) was compared with a group treated without complications. We found that neither single reference points nor combinations of them are good predictors of late complications (p greater than 0.5). The same applies for the dose prescribed in point A. In contrast, volume calculations proved to be highly reliable, both in single applications as well as in cumulative calculations. It is concluded that, within the given treatment schedule, volumes up to 300 cm3 (as defined by ICRU report 38) can be treated safely.