title: The impact of narrow band imaging for colon polyp detection: a multicenter randomized controlled trial by tandem colonoscopy.
abstract: BACKGROUND
  Previous studies have yielded conflicting results on the adenoma detection rate with narrow band imaging (NBI) compared with white light imaging (WLI). To overcome the confounding factors of these studies, we aimed to evaluate the colonic adenoma detection rate with primary NBI versus that with primary WLI by using consistent NBI system, endoscope, and imaging settings, and experienced colonoscopists.
  
  
  METHODS
  In this multicenter prospective trial, 813 patients were randomized to undergo high-definition, tandem colonoscopy in the right colon with either NBI followed by WLI (NBI-WLI group) or WLI followed by NBI (WLI-NBI group). The NBI settings were fixed at surface structure enhancement level A-5 and adaptive index of hemoglobin color enhancement level 3. All detected polyps were resected or biopsied for histopathological analysis. The primary and secondary outcome measures were the adenoma detection rates and miss rates, respectively, with primary imaging.
  
  
  RESULTS
  The NBI-WLI and WLI-NBI groups comprised 389 and 393 patients, respectively, who met the inclusion criteria. The groups did not differ significantly in age, gender, institution, indication for colonoscopy, bowel preparation, or observation time. The adenoma detection rates of primary NBI and WLI were 42.3 and 42.5 %, respectively [difference not significant (NS)]. The adenoma miss rate was significantly less with primary NBI than with primary WLI (21.3 vs. 27.8 %; p = 0.03).
  
  
  CONCLUSIONS
  NBI does not improve the adenoma detection rate during primary colonoscopy; however, it has a lower miss rate for adenoma lesions in the proximal colon than WLI.
authors.affiliation: Department of Gastroenterology and Gastrointestinal Oncology, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba 277-8577, Japan. hikemats@east.ncc.go.jp
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ikematsu
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Saito
authors.forename: Shinji
authors.initials: S
authors.lastname: Tanaka
authors.forename: Toshio
authors.initials: T
authors.lastname: Uraoka
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Sano
authors.forename: Takahiro
authors.initials: T
authors.lastname: Horimatsu
authors.forename: Takahisa
authors.initials: T
authors.lastname: Matsuda
authors.forename: Shiro
authors.initials: S
authors.lastname: Oka
authors.forename: Reiji
authors.initials: R
authors.lastname: Higashi
authors.forename: Hideki
authors.initials: H
authors.lastname: Ishikawa
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kaneko
mesh_terms: D000236:Adenoma / Q000175:diagnosis* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003106:Colon / Q000473:pathology*; D003110:Colonic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D003111:Colonic Polyps / Q000175:diagnosis* / Q000473:pathology; D003113:Colonoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D062048:Narrow Band Imaging / Q000379:methods*; D011446:Prospective Studies