title: Virtual chromoendoscopy (I-SCAN) detects more polyps in patients with Lynch syndrome: a randomized controlled crossover trial.
abstract: Background and study aims(Virtual) chromoendoscopy detects more polyps than standard white-light endoscopy in patients with Lynch syndrome. Previous back-to-back trials did not randomize for the examination order, creating a possible bias in favor of chromoendoscopy. We aimed to assess the difference in polyp detection between high definition white-light endoscopy (HD-WLE) and virtual chromoendoscopy with I-SCAN in patients with Lynch syndrome.Patients and methodsIn this prospective, controlled trial, patients were randomized to either HD-WLE followed by I-SCAN (Group 1; n = 31) or I-SCAN followed by HD-WLE (Group 2; n = 30). Polyps found during the first pass were removed. The primary end point of the study was the difference in adenoma detection between HD-WLE and I-SCAN, expressed as the miss rate for adenomas for each technique.ResultsIn Group 1, I-SCAN detected four additional patients with at least one adenoma, whereas HD-WLE did not increase the adenoma detection rate in Group 2 (relative risk [RR] 0.4;P= 0.08). In Group 1, five adenomas were detected and removed with HD-WLE and a second pass with I-SCAN detected a further eight adenomas. In Group 2, I-SCAN detected 15 adenomas and subsequent HD-WLE detected 2 additional adenomas. The adenoma miss rate was significantly higher for HD-WLE (62 %) compared with I-SCAN (12 %; RR 0.44, 95 % confidence interval [CI] 0.21 to 0.87;P= 0.007). The miss rate for lesions was 57 % and 24 %, respectively, and was significantly different in favor of I-SCAN (RR 0.54, 95 %CI 0.3 to 0.85;P= 0.005). The mean inspection time in both groups was not significantly different during first (485 vs. 536 seconds; 95 %CI - 139.91 to 33.34) or second pass (421 vs. 387 seconds; 95 %CI - 32.24 to 104.89).ConclusionOur data suggest that virtual chromoendoscopy with I-SCAN reduces the adenoma and polyp miss rate in patients with Lynch syndrome, independently of inspection time.
  
  
  BACKGROUND
  ClinicalTrials.gov (NCT01823471).
authors.affiliation: Department of Gastroenterology, University Hospital Leuven, Leuven, Belgium.
authors.forename: Raf
authors.initials: R
authors.lastname: Bisschops
authors.affiliation: Department of Gastroenterology, University Hospital Leuven, Leuven, Belgium.
authors.forename: Sabine
authors.initials: S
authors.lastname: Tejpar
authors.affiliation: Department of Gastroenterology, University Hospital Leuven, Leuven, Belgium.
authors.forename: Hilde
authors.initials: H
authors.lastname: Willekens
authors.affiliation: Department of Pathology, University Hospital Leuven, Leuven, Belgium.
authors.forename: Gert
authors.initials: G
authors.lastname: De Hertogh
authors.affiliation: Department of Gastroenterology, University Hospital Leuven, Leuven, Belgium.
authors.forename: Eric
authors.initials: E
authors.lastname: Van Cutsem
mesh_terms: D000236:Adenoma / Q000000981:diagnostic imaging*; D000328:Adult; D003110:Colonic Neoplasms / Q000000981:diagnostic imaging*; D003113:Colonoscopy / Q000379:methods*; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000000981:diagnostic imaging*; D018592:Cross-Over Studies; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D061646:Operative Time; D011446:Prospective Studies