title: Treatment outcomes after adjuvant radiotherapy following surgery for patients with stage I endometrial cancer.
abstract: OBJECTIVE
  The purpose of this study is to evaluate the treatment outcomes of adjuvant radiotherapy using vaginal brachytherapy (VB) with a lower dose per fraction and/or external beam radiotherapy (EBRT) following surgery for patients with stage I endometrial carcinoma.
  
  
  METHODS
  The subjects were 43 patients with the International Federation of Gynecology and Obstetrics (FIGO) stage I endometrial cancer who underwent adjuvant radiotherapy following surgery between March 2000 and April 2014. Of these, 25 received postoperative VB alone, while 18 received postoperative EBRT to the whole pelvis; 3 of these were treated with EBRT plus VB. The median EBRT dose was 50.0 Gy (45.0-50.4 Gy) and the VB dose was 24 Gy in 6 fractions. Tumor dose was prescribed at a depth of 5 mm from the cylinder surface and delivered twice per week.
  
  
  RESULTS
  The median follow-up period for all patients was 57 months (range, 9 to 188 months). Five-year disease-free survival (DFS) and overall survival (OS) for all patients were 92.5% and 95.3%, respectively. Adjuvant radiotherapy was performed according to risk factors and stage IB, grade 3 and lymphovascular invasion were observed more frequently in the EBRT group. Five-year DFS for EBRT and VB alone were 88.1% and 96.0%, respectively (p = 0.42), and 5-year OS for EBRT and VB alone were 94.4% and 96%, respectively (p = 0.38). There was no locoregional recurrence in any patient. Two patients who received EBRT and 1 patient who received VB alone developed distant metastatic disease. Two patients who received EBRT had severe complications, one each of grade 3 gastrointestinal complication and pelvic bone insufficiency fracture.
  
  
  CONCLUSIONS
  Adjuvant radiotherapy achieved high DFS and OS with acceptable toxicity in stage I endometrial cancer. VB (with a lower dose per fraction) may be a viable option for selected patients with early-stage endometrial cancer following surgery.
authors.affiliation: Department of Radiation Oncology, Ewha Womans University School of Medicine, Seoul, Korea.
authors.forename: Jiyoung
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Ewha Womans University School of Medicine, Seoul, Korea.
authors.forename: Kyung-Ja
authors.initials: KJ
authors.lastname: Lee
authors.affiliation: Department of Radiation Oncology, Ewha Womans University School of Medicine, Seoul, Korea.
authors.forename: Kyung-Ran
authors.initials: KR
authors.lastname: Park
authors.affiliation: Proton Therapy Center, National Cancer Center, Goyang, Korea.
authors.forename: Boram
authors.initials: B
authors.lastname: Ha
authors.affiliation: Department of Radiation Oncology, Ewha Womans University School of Medicine, Seoul, Korea.
authors.forename: Yi-Jun
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Ewha Womans University School of Medicine, Seoul, Korea.
authors.forename: Wonguen
authors.initials: W
authors.lastname: Jung
authors.affiliation: Department of Radiation Oncology, Ewha Womans University School of Medicine, Seoul, Korea.
authors.forename: Rena
authors.initials: R
authors.lastname: Lee
authors.affiliation: Department of Obstetrics and Gynecology, Ewha Womans University School of Medicine, Seoul, Korea.
authors.forename: Seung Cheol
authors.initials: SC
authors.lastname: Kim
authors.affiliation: Department of Obstetrics and Gynecology, Ewha Womans University School of Medicine, Seoul, Korea.
authors.forename: Hye Sung
authors.initials: HS
authors.lastname: Moon
authors.affiliation: Department of Obstetrics and Gynecology, Ewha Womans University School of Medicine, Seoul, Korea.
authors.forename: Woong
authors.initials: W
authors.lastname: Ju
authors.affiliation: Department of Obstetrics and Gynecology, Ewha Womans University School of Medicine, Seoul, Korea.
authors.forename: Yun Hwan
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Ewha Womans University School of Medicine, Seoul, Korea.
authors.forename: Jihae
authors.initials: J
authors.lastname: Lee
keywords: Adjuvant radiotherapy; Conformal radiotherapy; Endometrial cancer; Intracavity radiotherapy