Comparative results of three short brachytherapy schedules as exclusive treatment in postoperative endometrial...

To compare vaginal control and treatment toxicity of three different high-dose-rate brachytherapy schedules as exclusive treatment in postoperative endometrial carcinoma.

From 2003 to 2015, three different schedules were used as postoperative treatment for 146 patients (p) with intermediate-risk endometrial carcinoma. Group 1 (41 p): six fractions of 4-6 Gy, 3-4 fractions per week; Group 2 (59 p): four fractions of 5-6 Gy administered daily; Group 3 (46 p): 6 Gy × 3 fractions in three consecutive days. The dose was prescribed at 5 mm of applicator surface using an active treatment length of 2.5 cm. Toxicity scores were evaluated using the Radiation Therapy Oncology Group scores for bladder and rectum and the objective criteria of late effects of normal tissues-subjective, objective, management, analytic for vagina. Statistics used were group descriptions calculating their means, medians, and ranges. Bivariate analysis was evaluated using variance models and χ² tests.

The mean followup was as follows: Group 1: 88 months, Group 2: 75 months, and 41 months in Group 3. No vaginal relapses were found. Late toxicity ≥ G2: rectum: 0 p in the three groups (0%). Bladder: Group 1: 1 p (2.4%), Group 2: 0%, and Group 3: 0%. Vagina: Group 1: 4 p (9.5%); Group 2: 9 p (15.3%); and Group 3:10 p (21.8%). There were no differences in late toxicity among the three groups of patients for rectum (p = 0.83), bladder (p = 0.58), and vagina (p = 0.67); the expected global risk of complications for rectum, bladder, and vagina is 0.8%, 0.8%, and 28.8%, respectively.

Similar results in vaginal control and complications were achieved with the three schedules. The use of three fractions of 6 Gy administered daily is the best option for patient comfort and convenience and use of resources. Nonetheless, specific studies are needed to demonstrate the best cost-efficacy regime.