title: Intensity-modulated radiation therapy for pelvic oligo-recurrence from rectal cancer: long-term results from a single institution.
abstract: BACKGROUND
  Pelvic oligo-recurrence is common in rectal cancer patients, and some could not achieve radical resection.
  
  
  OBJECTIVE
  The study was to analyze long-term outcomes and prognostic factors associated with survival in patients treated with intensity-modulated radiation therapy (IMRT).
  
  
  METHODS
  Study participants were identified from rectal patients with pelvic oligo-recurrence without distant metastases, who were not suitable for surgery (n=135). Patients were recommended to receive concurrent chemotherapy in the course of IMRT (median dose 64.5 Gy, range: 45-70 Gy). Additionally, 24.4% (33/135) of patients received radical surgery after preoperative radiotherapy. Median time to pelvic failure was 25.4 months (range: 1-144 months). With a median follow-up period of 45.5 months (range: 3-104 months), 5-year overall survival (OS) and disease-free survival (DFS) were 55.6% and 45.5%, respectively.
  
  
  RESULTS
  In univariate survival analysis, OS stratified by subsites indicated that 5-year OS for anastomotic recurrence (80.5%) was better than for anterior recurrence (57.7%) and other pelvic oligo-recurrences (44.5%) (P=0.005). Five-year DFS in the three groups was 60.3%, 49% and 36.6%, respectively (P=0.037). In multivariate survival analysis, pelvic oligo-recurrence and symptomatic recurrence patterns were independently associated with OS in recurrent rectal cancer after pelvic radiotherapy (RT).
  
  
  CONCLUSIONS
  These results indicate that RT for rectal cancer patients with pelvic oligo-recurrence had favorable prognosis, especially for patients with anastomotic recurrence.
authors.affiliation: Department of Radiation Oncology, Peking University People's Hospital Beijing, 100044, P.R. China.
authors.forename: Xiang-Gao
authors.initials: XG
authors.lastname: Zhu
authors.affiliation: Department of Radiation Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University Cancer Hospital & Institute Beijing, 100142, P.R. China.
authors.forename: Yong-Heng
authors.initials: YH
authors.lastname: Li
authors.affiliation: Department of Radiation Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University Cancer Hospital & Institute Beijing, 100142, P.R. China.
authors.forename: Xiao-Fan
authors.initials: XF
authors.lastname: Li
authors.affiliation: Department of Radiation Oncology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University Cancer Hospital & Institute Beijing, 100142, P.R. China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Cai
keywords: Rectal cancer; intensity-modulated radiation therapy; pelvic oligo-recurrence