HIGH-DOSE-RATE BRACHYTHERAPY FOR CARCINOMA OF THE UTERINE CERVIX - COMPARISON OF 2 DIFFERENT FRACTIONATION REGIMENS

Purpose: There is no consensus as to the best dose-fractionation regim en in high dose rate (HDR) brachytherapy for cervix cancer. Since 1983 , two fractionation regimens have been used in different time periods at National Cancer Center Hospital, and their treatment results have b een compared in terms of 5-year survival, local control, and complicat ion rate to find the better therapeutic regimen. Methods and Materials : From November 1983 to October 1990, 130 patients with uterine cervix carcinoma were treated with HDR intracavitary brachytherapy using a r emote afterloading system. There were 21 Stage Ib patients, 5 Stage II a, 29 Stage IIb, 2 Stage IIIa, 68 Stage IIIb, and 5 Stage IVa. The med ian age was 64 years. The median follow-up time was 50 months. Radioth erapy consisted of external beam irradiation to the pelvis (mean dose of 50 Gy), combined with HDR brachytherapy (mean dose of 20 Gy to poin t A) given 5 Gy per session twice weekly (group A: 54 patients) or 6 G y once weekly (group B: 76 patients). Results: The overall 5-year surv ival was 52% in group A and 72% in group B. Local recurrence rate was 11%, and distant failure rate was 21%, with no difference between the two groups. The complication rate was significantly lower in group B ( 37%) than in group A (55%). Multivariate analysis has shown that facto rs affecting survival were stage, brachytherapy dose, and local contro l status. No factor was predictive of local control, but the external beam radiation dose significantly influenced the risk of complications . Conclusion: The once-weekly HDR intracavitary applications combined with properly adjusted external beam pelvic irradiation is a safe and effective treatment for patients with uterine cervix cancer.