Treatment Optimization of Pelvic External Beam Radiation With/or Vaginal Brachytherapy for Patients with Stage I to II High-Risk Endometrioid Adenocarcinoma: A Retrospective Multi-Institutional Analysis.

Purpose/Objective(s) For stage I to II high-risk endometrioid adenocarcinoma patients, the optimal adjuvant radiotherapy modality remains controversial. The present study sought to optimize the treatment of pelvic external beam radiation (EBRT) with/or vaginal brachytherapy (VBT) for high-risk endometrioid adenocarcinoma patients in multiple radiation oncology centers across China. Materials/Methods This article retrospectively reviewed stage I to II resected endometrioid adenocarcinoma patients treated at 13 radiation centers from Jan. 1999 to Dec. 2015. Patients were eligible if they had high-risk features (stage IB Grade 3 disease or stage II Grade 1-3 disease) on the basis of ESMO-ESGO-ESTRO risk group consensus. Results A total of 218 patients were included in the analysis. Lymphadenectomy was achieved in 87.2% of all patients. Fifty-one patients received adjuvant EBRT (EBRT group), 25 patients received VBT (VBT group), and 142 patients were administered EBRT combined with VBT (EBRT + VBT group). The three groups were comparable in baseline characteristics, except that the proportion of stage IBand Grade 3 disease in the VBT group was significantly higher and their age was older (P Conclusion For patients with postoperative stage I to II high-risk endometrioid adenocarcinoma, compared with VBT alone, pelvic radiation significantly improved DFS, LRFS and DMFS with tolerable adverse effects. Survival outcomes were not significantly different between the EBRT and EBRT + VBT modalities. Author Disclosure W. Wang: None. L. Zou: None. T. Wang: None. Z. Liu: None. J. He: None. X. Sun: None. W. Zhong: None. F. Zhao: None. X. Li: None. S. Li: None. H. Zhu: None. Z. Ma: None. S. Sun: None. M. Jin: None. F. Zhang: None. X. Hou: None. L. Wei: None. K. Hu: None.