title: Results of a pooled analysis of IOERT containing multimodality treatment for locally recurrent rectal cancer: Results of 565 patients of two major treatment centres.
abstract: OBJECTIVE
  Aim of this study is analysing the pooled results of Intra-Operative Electron beam Radiotherapy (IOERT) containing multimodality treatment of locally recurrent rectal cancer (LRRC) of two major treatment centres.
  
  
  METHODS
  Five hundred sixty five patients with LRRC who underwent multimodality-treatment up to 2010 were studied. The preferred treatment was preoperative chemo-radiotherapy, surgery and IOERT. In uni- and multivariate analyses risk factors for local re-recurrence, distant metastasis free survival, relapse free survival, cancer-specific survival and overall survival were studied.
  
  
  RESULTS
  Two hundred fifty one patients (44%) underwent a radical (R0) resection. In patients who had no preoperative treatment the R0 resection rate was 26%, and this was 43% and 50% for patients who respectively received preoperative re-(chemo)-irradiation or full-course radiotherapy (p < 0.0001). After uni- and multivariate analysis it was found that all oncologic parameters were influenced by preoperative treatment and radicality of the resection. Patients who were re-irradiated had a similar outcome compared to patients, who were radiotherapy naive and could undergo full-course treatment, except the chance of local re-recurrence was higher for re-irradiated patients. Waiting-time between preoperative radiotherapy and IOERT was inversely correlated with the chance of local re-recurrence, and positively correlated with the chance of a R0 resection.
  
  
  CONCLUSIONS
  R0 resection is the most important factor influencing oncologic parameters in treatment of LRRC. Preoperative (chemo)-radiotherapy increases the chance of achieving radical resections and improves oncologic outcomes. Short waiting-times between preoperative treatment and IOERT improves the effectiveness of IOERT to reduce the chance of a local re-recurrence.
authors.affiliation: Department of Surgery, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: F A
authors.initials: FA
authors.lastname: Holman
authors.affiliation: Department of Surgery, Catharina Hospital, Eindhoven, The Netherlands.
authors.forename: S J
authors.initials: SJ
authors.lastname: Bosman
authors.affiliation: Department of Radiation Oncology, Mayo Clinic, Rochester, MN, USA.
authors.forename: M G
authors.initials: MG
authors.lastname: Haddock
authors.affiliation: Department of Radiation Oncology, Mayo Clinic, Scottsdale, AZ, USA.
authors.forename: L L
authors.initials: LL
authors.lastname: Gunderson
authors.affiliation: Department of Surgery, Leiden University Medical Center, Leiden, The Netherlands; Department of Surgery, Catharina Hospital, Eindhoven, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Kusters
authors.affiliation: Department of Surgery, Catharina Hospital, Eindhoven, The Netherlands.
authors.forename: G A P
authors.initials: GA
authors.lastname: Nieuwenhuijzen
authors.affiliation: Department of Radiotherapy, Catharina Hospital, Eindhoven, The Netherlands.
authors.forename: H
authors.initials: H
authors.lastname: van den Berg
authors.affiliation: Department of Colon and Rectal Surgery, Mayo Clinic, Rochester, MN, USA.
authors.forename: H
authors.initials: H
authors.lastname: Nelson
authors.affiliation: Department of Surgery, Catharina Hospital, Eindhoven, The Netherlands; GROW: School of Oncology and Developmental Biology, University of Maastricht, Maastricht, The Netherlands. Electronic address: Harm.Rutten@cze.nl.
authors.forename: H J
authors.initials: HJ
authors.lastname: Rutten
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009426:Netherlands; D012004:Rectal Neoplasms / Q000473:pathology / Q000628:therapy*; D012307:Risk Factors; D016896:Treatment Outcome; D014481:United States
keywords: Chemo-radiation therapy; Intra Operative Electron beam Radiation Therapy; Local re-recurrence; Locally recurrent rectal cancer; Multimodality treatment; Re-irradiation