Time-gated fluorescence spectroscopy improves endoscopic detection of low-grade dysplasia in ulcerative colitis

BackgroundDysplasia in ulcerative colitis is frequently missed with 4-quadrant biopsies. An experimental setup recording delayed fluorescence spectra simultaneously with white light endoscopy was recently developed.ObjectiveWe compared detection of invisible flat intraepithelial neoplasia with protoporphyrin IX fluorescence and standard 4-quadrant biopsies.DesignProspective, crossover design without randomization of the order of procedures.SettingGastroenterology Department, Humboldt University, Charité, Berlin, Germany.PatientsForty-two patients with extensive ulcerative colitis of more than 10 years' duration were included.InterventionsColonoscopy with 4-quadrant biopsies and targeted biopsies of macroscopic lesions and time-gated fluorescence–guided colonoscopy were performed 2 weeks apart by 2 blinded endoscopists. Three independent pathologists examined the biopsy specimens.Main Outcome MeasurementsThe primary outcome criterion was detection rate of invisible flat intraepithelial neoplasia.ResultsInvisible flat intraepithelial neoplasia was detected in 3 (7%) patients by white light 4-quadrant biopsies and in 10 (24%) patients by fluorescence-guided endoscopy (P = .02). The sensitivity and specificity for differentiating patients with and without dysplasia were 100% and 81%, respectively. Dysplastic and nondysplastic mucosa could be discriminated with a sensitivity and specificity of 73% and 81%, respectively.LimitationsThe trial was not randomized.ConclusionThe detection rate of intraepithelial neoplasia in patients with ulcerative colitis can be improved by fluorescence-guided colonoscopy.