Preliminary accuracy and interobserver agreement for the detection of intraepithelial neoplasia in Barrett's esophagus with probe-based confocal laser endomicroscopy

BackgroundConfocal laser endomicroscopy (CLE) is a rapidly emerging method for in vivo imaging of the GI tract.ObjectiveTo determine the preliminary evaluation accuracy and interobserver agreement of probe-based CLE (pCLE) in Barrett's esophagus (BE).DesignProspective, double-blind review of pCLE images of 40 sites of BE tissue by using matching biopsies as the reference standard. A training set of 20 images with known histology was first reviewed to standardize image interpretation, followed by blinded review of 20 unknown images.SettingEleven experts in BE imaging from 4 different endoscopy centers from the United States and Europe evaluated the images.PatientsThis study involved nonconsecutive patients undergoing BE surveillance or evaluation of high-grade intraepithelial neoplasia or early adenocarcinoma.InterventionIntravenous fluorescein pCLE imaging of each site within the BE segment, followed by matching biopsy.Main Outcome MeasurementsSensitivity, specificity, and agreement for the pCLE diagnosis of high-grade intraepithelial neoplasia or carcinoma.ResultsIn the validation set (n = 20), 11 cases had high-grade intraepithelial neoplasia or invasive carcinoma. The sensitivity for the diagnosis of neoplasia for the 11 endoscopists was 88% (range 6 of 11 to 11 of 11), and the specificity was 96% (range 7 of 9 to 9 of 9). There was substantial agreement on the pCLE diagnosis (86%, kappa 0.72; 95% confidence interval, 0.58-0.86). Endomicroscopists with prior pCLE experience had an overall sensitivity of 91% (all 10 of 11), specificity of 100% (all 9 of 9), and almost perfect agreement (92%, kappa 0.83; 95% confidence interval, 0.64-1.0).LimitationsSmall sample size and use of offline video sequences.ConclusionResults suggest that pCLE for the diagnosis of neoplasia in BE has very high accuracy and reliability.