The purpose of the study was to compare postoperative vaginal irradiation with surgery alone in low-risk International Federation of Gynecology and Obstetrics (FIGO) stage IA-IB endometrial carcinoma. The study was a prospective, randomized trial of 645 evaluable low-risk endometrial carcinoma patients from 6 European gynecologic cancer centers. All tumors were in FIGO stage IA-IB, of endometrioid histological type, and FIGO grade 1-2. High-dose-rate afterloading equipments (iridium [Ir] 192 or cobalt [co] 60) were used at 5 centers, and low-dose-rate (LDR) afterloading equipment (cesium [CS] 137) at I center. Perspex vaginal applicators or ovoids were normally used, and the dose was specified at 5 mm from the surface of the applicator. Three to 6 fractions (3.0-8.0 Gy) were given, and the overall treatment time was 4 to 15 days. A total of 3 19 patients were treated with Surgery Plus vaginal irradiation (treatment group), and 326 patients with Surgery alone (control group).