A COMPARISON OF THE EFFICACY AND COMPLICATION RATES OF LOW DOSE-RATE VERSUS HIGH-DOSE-RATE BRACHYTHERAPY IN THE TREATMENT OF UTERINE CERVICAL-CARCINOMA

Purpose: To compare the outcome and complication rates for treatment o f uterine cervical carcinoma with low dose-rate (LDR) vs. high dose-ra te (HDR) brachytherapy at the University of Wisconsin Comprehensive Ca ncer Center (UWCCC). Methods and Materials: One-hundred ninety-eight e valuable patients with cervical carcinoma, Stages IB to IIIB, treated with curative intent with a combination of megavoltage teletherapy and LDR brachytherapy from 1977 to 1988 were the subject of an initial re view. In 1989, a HDR treatment program was initiated where all patient s with cervical carcinoma were subsequently treated with a combination of HDR brachytherapy and teletherapy. Using the linear-quadratic mode l (LQ), the dose and schedule of HDR brachytherapy and teletherapy wer e designed to give similar tumor control and late effects as LDR thera py. Technically, the HDR schedule required meticulous attention to tre atment geometry to limit severe late effects. Forty patients treated w ith the HDR program with 2-4 year follow-up were reviewed and compared to the previous LDR patient group. The LDR and HDR treatment groups w ere comparable with regards to age, weight, stage distribution, bulk o f disease, and histology. Results: No significant difference in surviv al was found between the LDR and HDR groups with 3-year actuarial over all survival being 66% and 77%, respectively. Three-year actuarial pel vic control rates were similar at 80% and 77% for the LDR and HDR grou ps, respectively. No significant difference in late treatment complica tions requiring hospitalization or surgery was found between the two t reatment groups with a complication rate of 10% (20/198) for the LDR p atients and 2.5% (1/40) for the HDR patients. Conclusion: As predicted by our LQ calculations, treatment results for LDR and HDR brachythera py were similar with respect to survival, pelvic control and late comp lications in the treatment of cervical carcinoma. The HDR brachytherap y program at the UWCCC appears to be a safe and effective alternative to LDR therapy in the treatment of cervical carcinoma.