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

Background

Dysplasia 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.

Objective

We compared detection of invisible flat intraepithelial neoplasia with protoporphyrin IX fluorescence and standard 4-quadrant biopsies.

Design

Prospective, crossover design without randomization of the order of procedures.

Setting

Gastroenterology Department, Humboldt University, Charité, Berlin, Germany.

Patients

Forty-two patients with extensive ulcerative colitis of more than 10 years' duration were included.

Interventions

Colonoscopy 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 Measurements

The primary outcome criterion was detection rate of invisible flat intraepithelial neoplasia.

Results

Invisible 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.

Limitations

The trial was not randomized.

Conclusion

The detection rate of intraepithelial neoplasia in patients with ulcerative colitis can be improved by fluorescence-guided colonoscopy.

Abbreviations: HGIN, high-grade intraepithelial neoplasia, IN, intraepithelial neoplasia, LGIN, low-grade intraepithelial neoplasia, 4-QB, 4-quadrant biopsy, PpIX, protoporphyrin IX