OBJECTIVE: To examine the outcomes (tolerability, toxicity, and recurrence) of vaginal brachytherapy (VBT) among endometrial cancer (EC) patients treated with small cylinder size. METHODS: Patients with EC who received adjuvant VBT between September 2011 and December 2015 were reviewed. Patients were fitted with the largest vaginal cylinder they could comfortably accommodate, from 2.0–3.0 cm diameter. Small cylinders were defined as size 2.3 cm or less. Patient, tumor, or treatment characteristics were correlated with need for small cylinders. Treatment tolerability, measures of gastrointestinal (GI), genitourinary (GU), and vaginal toxicity, and rates of recurrence were analyzed. RESULTS: Three hundred four patients were included. Small cylinders were used in 51 patients (17%). Normal body mass index (BMI; p<0.001), nulligravidity (p<0.001), and shorter vaginal length (p<0.001) were associated with small cylinder size. There was no acute or late grade 3 toxicity. Rates of acute (grade 1–2) GI, GU, or vaginal symptoms were low (10%, 11%, and 19%, respectively). Small cylinder size was associated with increased likelihood of reporting acute GI (p<0.05) but not GU or vaginal symptoms. Small cylinder size was associated with higher risk of grade 1–2 vaginal stenosis (odds ratio [OR]=4.7; 95% confidence interval [CI]=1.5–14.7; p=0.007). There was no association between cylinder size and recurrence rate (p=0.55). CONCLUSION: VBT is generally very well tolerated, however, patients fitted with smaller cylinders (commonly nulligravid and low BMI) may have increased side effects. Further study to improve the dosimetry of VBT for patients requiring small cylinders may be worthwhile.
Body Mass Index ; Brachytherapy* ; Constriction, Pathologic ; Endometrial Neoplasms* ; Female ; Gravidity ; Humans ; Recurrence

Objective: To examine outcomes in a modern treatment era for stage III uterine serous carcinoma (USC). Methods: Fifty women were retrospectively identified as 2009 International Federation of Gynecology and Obstetrics stage III USC patients who received radiotherapy (RT) at our institution between 1/2003–5/2018. The patients were divided into 2 cohorts: 20 in the early era (2003–2010) and 30 in the modern era (2011–2018). Patient characteristics were compared using χ 2 tests for categorical variables and t-tests for continuous variables. Recurrence free survival (RFS) and overall survival (OS) were analyzed with Kaplan-Meier estimates, the logrank test, and Cox proportional hazards. Results: The modern era differed from the early era in the increased use of volume-directed external beam RT (EBRT) as opposed to vaginal brachytherapy (VB) alone (33.3% vs 5.0%, p=0.048), minimally invasive surgery (56.7% vs. 25%, p=0.027), sentinel node sampling (26.7% vs. 0%, p=0.012), computed tomography imaging in the perioperative period (63.3% vs. 30%, p=0.044), and human epidermal growth factor receptor 2eu testing (96.7% vs.55%, p=0.001). Median follow-up for early and modern eras was 37.27 and 33.23 months, respectively. The early vs. modern 3-year RFS was 33% and 64% (p=0.039), respectively, while the 3-year OS was 55% and 90% (p=0.034). Regional nodal recurrence more common among the patients who received VB only (p=0.048). Conclusion Modern era treatment was associated with improved RFS and OS in patients with stage III USC. Regional nodal recurrences were significantly reduced in patients who received EBRT.