Role of narrow band imaging in the diagnosis of laryngeal lesions: Pilot study from India.

INTRODUCTION: Narrow band imaging (NBI) is a new imaging technique developed to improve the diagnostic accuracy of head and neck cancers by depiction of tumor-specific neo-angiogenesis. The purpose of this study was to assess the value of NBI in the diagnosis of laryngeal lesions.

AIM: To assess the sensitivity and specificity of combined white light endoscopy (WLE) and NBI compared with WLE alone in the diagnosis of laryngeal lesions.

SETTINGS AND DESIGN: Prospective study.

MATERIALS AND METHODS: Thirty consecutive patients with various laryngeal lesions scheduled for microlaryngoscopic evaluation underwent WLE followed by NBI. Endoscopic NBI findings were classified into five types (I-V) according to the intraepithelial papillary capillary loop features. Types I-IV are considered benign, whereas type V is considered malignant. The observations were compared with histopathology.

STATISTICAL ANALYSIS: Sensitivity, specificity, and positive and negative predictive values for the diagnosis of malignancy (i.e., invasive carcinoma and carcinoma in situ) by means of NBI with WLE were calculated.

RESULTS: The sensitivity of WLE combined with NBI (100%) was higher than WLE alone (82.6%) in detecting laryngeal cancers. NBI helped in identifying four malignant lesions missed by WLE alone. Two children with respiratory papillomatosis also demonstrated type V pattern, a potential pitfall, leading to an overall positive predictive value of 92% and a negative predictive value of 100%.

CONCLUSION: Combining NBI with WLE increases the sensitivity of detection of laryngeal cancer and its precursor lesions. NBI is also useful in some benign lesions as well as in post-radiotherapy patients.