Detection of high-grade dysplasia, carcinoma in situ and squamous cell carcinoma in the upper aerodigestive tract: Recommendations for optimal use and interpretation of narrow band imaging

Objectives: The primary goal was to study the diagnostic potential of narrow-band imaging (NBI), and the secondary goal was to evaluate the most common mistakes when using and interpreting NBI.

Design: Retrospective study.

Setting: University Medical Center Groningen, tertiary referral hospital, the Netherlands.

Participants: Three hundred and seventy patients who underwent rigid endoscopy of the upper aerodigestive tract. Two observers assessed all lesions. Twelve observers assessed a selection of 100 lesions. All observers were provided with both white light imaging and NBI.

Main outcome measures: Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy and reasons for insufficient photograph quality.

Results: When using NBI, the sensitivity, specificity, PPV, NPV and accuracy for detecting invasive carcinoma, carcinoma in situ or high-grade dysplasia were 92%, 68%, 61%, 94% and 77%, respectively. In multiple-observer analysis, values were 76%, 58%, 53%, 83% and 65% with the evaluation strictly based on type V patterns of Ni's classification, vs 83%, 68%, 64%, 85% and 74% when evaluation was also based on lesion-specific clinical characteristics. Lesions that caused misinterpretations were leukoplakia, papillomas and mucosal lesions after irradiation. In total, 185 photographs were assessed to be of suboptimal quality due to blurring (36%), bleeding (6%), insufficient zooming (15%) and/or insufficient lighting (17%).

Conclusion: NBI is a relatively reliable screening method for detecting malignancy. Evaluation based on Ni's classification alone is not sufficient. To optimise NBI photograph quality, we recommend sufficient zooming and prevention of bleeding, blurring and inadequate lighting.