title: In vivo real-time assessment of colorectal polyp histology using an optical biopsy forceps system based on laser-induced fluorescence spectroscopy.
abstract: OBJECTIVE
  In order to reduce time, costs, and risks associated with resection of diminutive colorectal polyps, the American Society for Gastrointestinal Endoscopy (ASGE) recently proposed performance thresholds that new technologies should meet for the accurate real-time assessment of histology of colorectal polyps. In this study, we prospectively assessed whether laser-induced fluorescence spectroscopy (LIFS), using the new WavSTAT4 optical biopsy system, can meet the ASGE criteria.
  
  
  METHODS
  27 patients undergoing screening or surveillance colonoscopy were included. The histology of 137 diminutive colorectal polyps was predicted in real time using LIFS and findings were compared with the results of conventional histopathological examination. The accuracy of predicting polyp histology with WavSTAT4 was assessed according to the ASGE criteria.
  
  
  RESULTS
  The overall accuracy of LIFS using WavSTAT4 for predicting polyp histology was 84.7 % with sensitivity, specificity, and negative predictive value (NPV) of 81.8 %, 85.2 %, and 96.1 %. When only distal colorectal diminutive polyps were considered, the NPV for excluding adenomatous histology increased to 100 % (accuracy 82.4 %, sensitivity 100 %, specificity 80.6 %). On-site, LIFS correctly predicted the recommended surveillance intervals with an accuracy of 88.9 % (24/27 patients) when compared with histology-based United States guideline recommendations; in the 3 patients for whom LIFS- and histopathology-based recommended surveillance intervals differed, LIFS predicted shorter surveillance intervals.
  
  
  CONCLUSIONS
  From the data of this pilot study, LIFS using the WavSTAT4 system appears accurate enough to allow distal colorectal polyps to be left in place and nearly reaches the threshold to "resect and discard" them without pathologic assessment. WavSTAT4 therefore has the potential to reduce costs and risks associated with the removal of diminutive colorectal polyps.
authors.affiliation: Department of Medicine I, Division of Gastroenterology, Pneumology and Endocrinology, University Hospital Erlangen, Germany.
authors.forename: Timo
authors.initials: T
authors.lastname: Rath
authors.affiliation: Department of Medicine I, Division of Gastroenterology, Pneumology and Endocrinology, University Hospital Erlangen, Germany.
authors.forename: Gian E
authors.initials: GE
authors.lastname: Tontini
authors.affiliation: Institute of Pathology, Klinikum Bayreuth, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Vieth
authors.affiliation: Department of Medicine I, Division of Gastroenterology, Pneumology and Endocrinology, University Hospital Erlangen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Nägel
authors.affiliation: Department of Medicine I, Division of Gastroenterology, Pneumology and Endocrinology, University Hospital Erlangen, Germany.
authors.forename: Markus F
authors.initials: MF
authors.lastname: Neurath
authors.affiliation: Department of Medicine I, Division of Gastroenterology, Pneumology and Endocrinology, University Hospital Erlangen, Germany.
authors.forename: Helmut
authors.initials: H
authors.lastname: Neumann
mesh_terms: D000236:Adenoma / Q000000981:diagnostic imaging* / Q000473:pathology; D000328:Adult; D000368:Aged; D001706:Biopsy; D003106:Colon / Q000473:pathology*; D003111:Colonic Polyps / Q000000981:diagnostic imaging* / Q000473:pathology*; D003113:Colonoscopy / Q000295:instrumentation; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D007834:Lasers; D008297:Male; D008875:Middle Aged; D055100:Optical Fibers; D061848:Optical Imaging / Q000379:methods*; D017410:Practice Guidelines as Topic; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012007:Rectum / Q000473:pathology*; D016037:Single-Blind Method; D013050:Spectrometry, Fluorescence / Q000379:methods; D055815:Young Adult