Intravaginal high-dose-rate brachytherapy for Stage IB (FIGO Grade 1, 2) endometrial cancer.

PURPOSE: To evaluate the outcome of patients with Stage IB Grades 1 and 2 endometrial cancer treated with adjuvant high-dose-rate intravaginal brachytherapy.

METHODS AND MATERIALS: Between November 1987 and October 1999, 233 patients with Stage IB FIGO Grades 1 and 2 were treated with postoperative adjuvant high-dose-rate intravaginal brachytherapy. The median dose was 21 Gy in 7 Gy/fraction given at 2-week intervals. The mean age was 60 years. All patients underwent simple hysterectomy. Comprehensive surgical staging, defined as pelvic washing and pelvic and paraaortic lymph nodes sampling, was done in 9% of patients. Patients with FIGO Grade 3, papillary serous cancer, or clear-cell cancer were excluded from this analysis. Complications were assessed in terms of late Radiation Therapy Oncology Group toxicity (Grade > or =3) of the gastrointestinal tract, genitourinary tract, and vagina.

RESULTS: With a median follow-up of 57 months, the 5-year vaginal/pelvic control, disease-free survival, and overall survival rate was 96% (95% confidence interval [CI] 94-99%), 94% (95% CI 91-98%), and 94% (95% CI 91-98%), respectively. The influence on outcome of age, grade (1 vs. 2), depth of invasion (one-third or less or greater than one-third), capillary space-like invasion, lower uterine segment involvement, and comprehensive surgical staging was evaluated. None of these factors significantly affected the rate of vaginal/pelvic control. Only age > or =60 years influenced the outcome for disease-free and overall survival. The 5-year rate for both disease-free and overall survival was 90% (95% CI 84-97%) for patients > or =60 years old compared with 99% (95% CI 96-100%) for those <60 years (p = 0.03 and 0.005, respectively). Of 233 patients, 3 (1%) developed Grade 3 or greater complications, with a 5-year actuarial rate of 2% (95% CI 0-5%). Two patients developed Grade 3 genitourinary toxicity, and 1 Grade 4 vaginal toxicity.

CONCLUSION: On the basis of this retrospective study, adjuvant postoperative high-dose-rate intravaginal brachytherapy provides excellent outcomes and acceptable morbidity. These results compare very favorably with those reported in the literature using surgery alone or with pelvic radiation.