title: Combining autofluorescence imaging and narrow-band imaging for the differentiation of adenomas from non-neoplastic colonic polyps among experienced and non-experienced endoscopists.
abstract: OBJECTIVE
  Endoscopic tri-modal imaging incorporates high-resolution white-light endoscopy (HR-WLE), narrow-band imaging (NBI), and autofluorescence imaging (AFI). Combining these advanced techniques may improve endoscopic differentiation between adenomas and non-neoplastic polyps. In this study, we aimed to assess the interobserver variability and accuracy of HR-WLE, NBI, and AFI for polyp differentiation and to evaluate the combined use of AFI and NBI.
  
  
  METHODS
  First, still images of 50 polyps (22 adenomas; median 3 mm) were randomly displayed to three experienced and four non-experienced endoscopists. All HR-WLE and NBI images were scored for Kudo classification and AFI images for color. Second, the combined AFI and NBI images were assessed using a newly developed algorithm by six additional non-experienced endoscopists.
  
  
  RESULTS
  The outcomes measured were interobserver agreement and diagnostic accuracy using histopathology as reference standard. Experienced endoscopists had better interobserver agreement for NBI (kappa=0.77) than for AFI (kappa=0.33), whereas non-experienced endoscopists had better agreement for AFI (kappa=0.58) than for NBI (kappa=0.33). The accuracies of HR-WLE, NBI, and AFI among experienced endoscopists were 65, 70, and 74, respectively. Figures among non-experienced endoscopists were 57, 63, and 77. The algorithm was associated with a significantly higher accuracy of 85% among all observers (P<0.023). These figures were confirmed in the second evaluation study.
  
  
  CONCLUSIONS
  Non-experienced endoscopists have better interobserver agreement and accuracy for AFI than for HR-WLE or NBI, indicating that AFI is easier to use for polyp differentiation in non-experienced setting. The newly developed algorithm, combining information of AFI and NBI together, had the highest accuracy and obtained equal results between experienced and non-experienced endoscopists.
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Frank J C
authors.initials: FJ
authors.lastname: van den Broek
authors.forename: Ellert J
authors.initials: EJ
authors.lastname: van Soest
authors.forename: Anton H
authors.initials: AH
authors.lastname: Naber
authors.forename: Arnoud H A M
authors.initials: AH
authors.lastname: van Oijen
authors.forename: Rosalie Ch
authors.initials: RCh
authors.lastname: Mallant-Hent
authors.forename: Clarisse J M
authors.initials: CJ
authors.lastname: Böhmer
authors.forename: Pieter
authors.initials: P
authors.lastname: Scholten
authors.forename: Pieter C F
authors.initials: PC
authors.lastname: Stokkers
authors.forename: Willem A
authors.initials: WA
authors.lastname: Marsman
authors.forename: Elisabeth M H
authors.initials: EM
authors.lastname: Mathus-Vliegen
authors.forename: Wouter L
authors.initials: WL
authors.lastname: Curvers
authors.forename: Jacques J G H M
authors.initials: JJ
authors.lastname: Bergman
authors.forename: Susanne
authors.initials: S
authors.lastname: van Eeden
authors.forename: James C H
authors.initials: JC
authors.lastname: Hardwick
authors.forename: Paul
authors.initials: P
authors.lastname: Fockens
authors.forename: Johannes B
authors.initials: JB
authors.lastname: Reitsma
authors.forename: Evelien
authors.initials: E
authors.lastname: Dekker
mesh_terms: D000236:Adenoma / Q000473:pathology*; D000465:Algorithms; D002983:Clinical Competence; D003110:Colonic Neoplasms / Q000473:pathology*; D003111:Colonic Polyps / Q000473:pathology*; D003113:Colonoscopy / Q000379:methods*; D003937:Diagnosis, Differential; D005260:Female; D005453:Fluorescence; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D015203:Reproducibility of Results