The manufacturers of narrow band imaging (NBI) claim better visualisation of mucosal abnormalities when compared with simple white light. The primary aim of the study was to compare the diagnostic accuracy of NBI and white light to diagnose malignant laryngeal lesions. The study also examined the inter- and intra-observer reliability of these endoscopic imaging methods. Laryngeal images from 163 patients, who underwent biopsies of the laryngeal abnormalities, were retrospectively assessed by three ENT surgeons who were trained to use NBI.
Results showed NBI to be statistically more accurate (96.3%) and sensitive (93.3%) in diagnosing malignant lesions when compared with white light. Both methods had a high specificity (97.3%).
There was also high inter (kappa value 0.849) and intra-observer reliability for NBI compared to white light. The data from this paper supports the hypothesis that NBI is better than white light for diagnosis and follow-up of laryngeal cancer. The regular use of NBI in experienced hands could significantly improve diagnosis of laryngeal tumours and hence reduce unnecessary general anaesthetics.