title: Temporally and spectrally resolved fluorescence spectroscopy for the detection of high grade dysplasia in Barrett's esophagus.
abstract: OBJECTIVE
  Temporal and spectral fluorescence spectroscopy can identify adenomatous colonic polyps accurately. In this study, these techniques were examined as a potential means of improving the surveillance of high grade dysplasia (HGD) in Barrett's esophagus (BE).
  
  
  METHODS
  Using excitation wavelengths of 337 and 400 nm, 148 fluorescence spectra, and 108 transient decay profiles (at 550 +/- 20 nm) were obtained endoscopically in 37 patients. Corresponding biopsies were collected and classified as carcinoma, HGD, or low risk tissue (LRT) [non-dysplastic BE, indefinite for dysplasia (IFD), and low grade dysplasia (LGD)]. Diagnostic algorithms were developed retrospectively using linear discriminant analysis (LDA) to separate LRT from HGD.
  
  
  RESULTS
  LDA produced diagnostic algorithms based solely on spectral data. Moderate levels of sensitivity (Se) and specificity (Sp) were obtained for both 337 nm (Se = 74%, Sp = 67%) and 400 nm (Se = 74%, Sp = 85%) excitation.
  
  
  CONCLUSIONS
  In the diagnosis of HGD in BE, steady-state fluorescence was more effective than time-resolved data, and excitation at 400 nm excitation was more effective than 337 nm. While fluorescence-targeted biopsy is approaching clinical usefulness, increased sensitivity to dysplastic changes-possibly through modification of system parameters-is needed to improve accuracy levels.
authors.affiliation: Wellman Laboratories of Photomedicine and Gastrointestinal Unit, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA. josh@eob.cdrh.fda.gov
authors.forename: T Joshua
authors.initials: TJ
authors.lastname: Pfefer
authors.forename: Dilip Y
authors.initials: DY
authors.lastname: Paithankar
authors.forename: John M
authors.initials: JM
authors.lastname: Poneros
authors.forename: Kevin T
authors.initials: KT
authors.lastname: Schomacker
authors.forename: Norman S
authors.initials: NS
authors.lastname: Nishioka
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000209:etiology* / Q000473:pathology; D000465:Algorithms; D001471:Barrett Esophagus / Q000150:complications* / Q000175:diagnosis* / Q000473:pathology; D016145:Endoscopy, Digestive System; D004938:Esophageal Neoplasms / Q000175:diagnosis* / Q000209:etiology* / Q000473:pathology; D004947:Esophagus / Q000473:pathology / Q000528:radiation effects*; D006801:Humans; D028022:Low-Level Light Therapy; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence