[Postoperative radiotherapy in endometrial carcinoma. A retrospective analysis of 541 cases]

This retrospective study was designed to evaluate the role of adjuvant radiotherapy for surgically treated endometrial carcinoma.

From 1980 through 1988, 541 patients were treated with either intravaginal cuff irradiation with a high-dose-rate (HDR) Iridium-192 remote afterloading technique (n = 294) or with combined HDR-brachytherapy and additional external pelvic irradiation to 54 Gy (n = 247) after surgery for endometrial cancer. Afterloading irradiation was administered in 4 fractions 4 to 6 weeks after surgery. A dose of 30 Gy was delivered at a depth of 0.5 cm from the vaginal mucosa.

Patients with HDR-brachytherapy alone showed a 5-year survival of 94.3% for Stage I and 73.6% for Stage II (p = 0.0007). Patients who received both brachytherapy and additional external pelvic irradiation had a 5-year survival of 94.1% for Stage I, 81.1% for Stage II, 70.4% for Stage III and 46.9% for Stage IV (p = 0.0001). The main predictors for survival in a multivariate analysis were stage and grading. Patients with combined radiotherapy had a local recurrence rate of 3.2%, whereas patients with brachytherapy alone who were better selected and had more favorable prognostic factors showed a recurrence rate of 2%. Low-risk patients (Stage I, Grade 1, low infiltration) in the HDR-brachytherapy group had 6 relapses, mainly caused by insufficient treatment on the basis of papillary histology. High-risk patients with poorly differentiated tumors, which infiltrate more than half the myometrial wall might benefit from additional external radiotherapy in terms of reduction of local recurrence and better survival. Five-year actuarial survival rate was 93.6% after combined radiotherapy vs 86.7% after brachytherapy alone. Complications were graded according to the RTOG scoring system. Severe late complications were fistulas of bladder and/or bowel, which occurred in 2.8% in the combined radiotherapy group, and 0.7% in the HDR brachytherapy group.

Low-risk patients should be generally treated postoperative with HDR-brachytherapy alone. Combined radiotherapy decreased pelvic relapses for high-risk patients with overall low complication rates. We conclude that an individually adjusted postoperative radiotherapy allows a well tolerated treatment with excellent results.