Background: Endoscopic tri-modal imaging (ETMI) incorporates white light endoscopy (WLE), autofluorescence imaging (AFI) and narrow band imaging (NBI).
Aims: To assess the value of ETMI for the detection and classification of neoplasia in patients with longstanding ulcerative colitis.
Design: Randomized comparative trial of tandem colonoscopies.
Setting: Academic Medical Centre Amsterdam, Netherlands.
Patients and methods: Fifty patients with ulcerative colitis underwent surveillance colonoscopy with ETMI. Each colonic segment was inspected twice, once with AFI and once with WLE, in random order. All detected lesions were inspected by NBI for Kudo pit pattern analysis and additional random biopsies were taken.
Main outcome measures: Neoplasia miss-rates of AFI and WLE, and accuracy of the Kudo classification by NBI.
Results: Among patients assigned to inspection with AFI first (n=25), 10 neoplastic lesions were primarily detected. Subsequent WLE detected no additional neoplasia. Among patients examined with WLE first (n=25), 3 neoplastic lesions were detected; subsequent inspection with AFI added 3 neoplastic lesions. Neoplasia miss-rates for AFI and WLE were 0% and 50% (p=0.036). The Kudo classification by NBI had a sensitivity and specificity of 75% and 81%; however, all neoplasia was colored purple on AFI (sensitivity 100%). No additional patients with neoplasia were detected by random biopsies.
Conclusion: Autofluorescence imaging improves the detection of neoplasia in patients with UC and decreases the yield of random biopsies. Pit pattern analysis by NBI has a moderate accuracy for the prediction of histology, whereas AFI-color appears valuable in excluding the presence of neoplasia.