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

ABSTRACT

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.