title: A standardized imaging protocol is accurate in detecting recurrence after EMR.
abstract: OBJECTIVE
  EMR of large laterally spreading lesions (LSL) in the colon is a safe and effective alternative to surgery. Post-EMR scar assessment currently involves taking biopsy specimens of the scar to detect residual or recurrent adenoma (RRA). The accuracy of endoscopic imaging of the post-EMR scar is unknown. We aimed to determine the accuracy of a standardized imaging protocol in post-EMR scar assessment.
  
  
  METHODS
  Prospective, single-center data from the Australian Colonic EMR study were analyzed. Consecutive patients undergoing first surveillance colonoscopy (SC1) after EMR of a large LSL were eligible. All scars were sequentially examined with high-definition white light (HD-WL) and narrow-band imaging (NBI) in a standardized fashion and then biopsies were performed. Endoscopic recurrence (recurrence at the post-EMR scar detected by systematic endoscopic assessment) was compared with the histologic findings.
  
  
  RESULTS
  One hundred eighty-three post-EMR scars were included. Thirty of 183 (16.4%) were confirmed to have RRA histologically at SC1. Thirty-seven of 183 (20.2%) post-EMR scars demonstrated RRA endoscopically. The sensitivity and specificity of endoscopic RRA detection were 93.3% (95% confidence interval [CI], 77.9%-99.2%) and 94.1% (95% CI, 89.1%-97.3%), respectively. The positive predictive value was 75.7% (95% CI, 58.8%-88.2%) and the negative predictive value was 98.6% (95% CI, 95.1%-99.8%). The diagnostic accuracy was 94.0%. Sensitivity was higher for the combination of HD-WL and NBI as opposed to HD-WL alone (93.3% vs 66.7%). The specificity was high for both HD-WL and HD-WL + NBI (96.1% and 94.1%, respectively). Flat morphology of RRA was better seen with NBI (P = .002).
  
  
  CONCLUSIONS
  Endoscopic detection of RRA in the post-EMR scar is highly accurate using a standardized imaging protocol with HD-WL and NBI. This allows real-time, accurate detection of recurrence and its concurrent treatment, and raises the possibility that routine biopsy of the post-EMR scar may not be necessary.
authors.affiliation: Department of Gastroenterology and Hepatology, Westmead Hospital, Sydney, New South Wales, Australia.
authors.forename: Lobke
authors.initials: L
authors.lastname: Desomer
authors.affiliation: Department of Gastroenterology and Hepatology, Westmead Hospital, Sydney, New South Wales, Australia.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Tutticci
authors.affiliation: Department of Gastroenterology and Hepatology, Westmead Hospital, Sydney, New South Wales, Australia.
authors.forename: David J
authors.initials: DJ
authors.lastname: Tate
authors.affiliation: Department of Gastroenterology and Hepatology, Westmead Hospital, Sydney, New South Wales, Australia.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Williams
authors.affiliation: Institute of Clinical Pathology and Medical Research, Westmead Hospital, Sydney, New South Wales, Australia.
authors.forename: Duncan
authors.initials: D
authors.lastname: McLeod
authors.affiliation: Department of Gastroenterology and Hepatology, Westmead Hospital, Sydney, New South Wales, Australia; Westmead Clinical School, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Bourke
mesh_terms: D000236:Adenoma / Q000473:pathology / Q000601:surgery*; D000368:Aged; D002921:Cicatrix / Q000473:pathology*; D003110:Colonic Neoplasms / Q000473:pathology / Q000601:surgery*; D003113:Colonoscopy / Q000379:methods*; D000069916:Endoscopic Mucosal Resection; D005260:Female; D006801:Humans; D000069416:Intravital Microscopy; D008297:Male; D008875:Middle Aged; D062048:Narrow Band Imaging; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000473:pathology*; D018365:Neoplasm, Residual; D011446:Prospective Studies; D012680:Sensitivity and Specificity