EVALUATION OF LATE MORBIDITY IN PATIENTS WITH CARCINOMA OF THE UTERINE CERVIX FOLLOWING A DOSE-RATE CHANGE

Background: A retrospective analysis of late complications for patient s with cervical cancer treated with two different brachytherapy schedu les in one institute, using the French-Italian glossary. Materials and methods: From 1979 until 1986, a total of 77 patients were treated wi th external radiation followed by two intracavitary applications with the Gynatron Cs-137 afterloading (dose rate 0.54 Gy/h). After 1986, 66 patients received intracavitary applications with Selectron-LDR (dose rate 1.07 Gy/h). Because of the expected increase in complications wi th increasing dose rate, the dose per application was reduced from 25 Gy to 20 Gy. Results: 49/77 late gastrointestinal and urinary complica tions were scored in the Gynatron group and 46/68 in the Selectron gro up. Actuarial estimates at 5 years showed 42% and 54.1% late gastroint estinal complications and 16.9% and 24.1% for late urinary complicatio ns in the patients treated with, respectively, the Gynatron and Select ron. Conclusions: Despite the dose reduction, there remains a clear do se rate influence on the late morbidity. Correction for this influence is essential. (C) 1997 Elsevier Science Ireland Ltd.