title: Intraoperative radiotherapy in colorectal cancer: systematic review and meta-analysis of techniques, long-term outcomes, and complications.
abstract: BACKGROUND
  The precise contribution of IORT to the management of locally advanced and recurrent colorectal cancer (CRC) remains uncertain. We performed a systematic review and meta-analysis to assess the value of IORT in this setting.
  
  
  METHODS
  Studies published between 1965 and 2011 that reported outcomes after IORT for advanced or recurrent CRC were identified by an electronic literature search. Studies were assessed for methodological quality and design, and evaluated for technique of IORT delivery, oncological outcomes, and complications following IORT. Outcomes were analysed with fixed-effect and random-effect model meta-analyses and heterogeneity and publication bias examined.
  
  
  RESULTS
  29 studies comprising 14 prospective and 15 retrospective studies met the inclusion criteria and were assessed, yielding a total of 3003 patients. The indication for IORT was locally advanced disease in 1792 patients and locally recurrent disease in 1211 patients. Despite heterogeneity in methodology and reporting practice, IORT is principally applied for the treatment of close or positive margins. When comparative studies were evaluated, a significant effect favouring improved local control (OR 0.22; 95% CI = 0.05-0.86; p = 0.03), disease free survival (HR 0.51; 95% CI = 0.31-0.85; p = 0.009), and overall survival (HR 0.33; 95% CI = 0.2-0.54; p = 0.001) was noted with no increase in total (OR 1.13; 95% CI = 0.77-1.65; p = 0.57), urologic (OR 1.35; 95% CI = 0.84-2.82; p = 0.47), or anastomotic complications (OR 0.94; 95% CI = 0.42-2.1; p = 0.98). Increased wound complications were noted after IORT (OR 1.86; 95% CI = 1.03-3.38; p = 0.049).
  
  
  CONCLUSIONS
  Despite methodological weaknesses in the studies evaluated, our results suggest that IORT may improve oncological outcomes in advanced and recurrent CRC.
authors.affiliation: Section of Biosurgery & Surgical Technology, Department of Surgery & Cancer, Imperial College London, 10th Floor QEQM Building, St Mary's Hospital, London W2 1NY, UK.
authors.forename: Reza
authors.initials: R
authors.lastname: Mirnezami
authors.forename: George J
authors.initials: GJ
authors.lastname: Chang
authors.forename: Prajnan
authors.initials: P
authors.lastname: Das
authors.forename: Kandiah
authors.initials: K
authors.lastname: Chandrakumaran
authors.forename: Paris
authors.initials: P
authors.lastname: Tekkis
authors.forename: Ara
authors.initials: A
authors.lastname: Darzi
authors.forename: Alexander H
authors.initials: AH
authors.lastname: Mirnezami
mesh_terms: D006801:Humans; D015179:Colorectal Neoplasms / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D003131:Combined Modality Therapy; D007430:Intraoperative Care; D009364:Neoplasm Recurrence, Local / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D011879:Radiotherapy Dosage; D016896:Treatment Outcome