Fluorescence, reflectance, and light-scattering spectroscopy for evaluating dysplasia in patients with Barrett's esophagus

Background & Aims: The aim of this study was to assess the potential of 3 spectroscopic techniques (fluorescence, reflectance, and light-scattering spectroscopy) individually and in combination, for evaluating low- and high-grade dysplasia in patients with Barrett's esophagus (BE). Methods: Fluorescence spectra at 11 excitation wavelengths and a reflectance spectrum were acquired in approximately 1 second from each site before biopsy using an optical fiber probe. The measured fluorescence spectra were combined with the reflectance spectra to extract the intrinsic tissue fluorescence. The reflectance spectra provided morphologic information about the bulk tissue, whereas light-scattering spectroscopy was used to determine cell nuclear crowding and enlargement in Barrett's epithelium. Results: Significant differences were observed between dysplastic and nondysplastic BE in terms of intrinsic fluorescence, bulk scattering properties, and levels of epithelial cell nuclear crowding and enlargement. The combination of all 3 techniques resulted in superior sensitivity and specificity for separating high-grade from non-high-grade and dysplastic from nondysplastic epithelium. Conclusions: Intrinsic fluorescence, reflectance, and light-scattering spectroscopies provide complementary information about biochemical and morphologic changes that occur during the development of dysplasia. The combination of these techniques (Tri-Modal Spectroscopy) can serve as an excellent tool for the evaluation of dysplasia in BE.