Narrow Band Imaging as a Diagnostic Tool in Laryngeal Pathology

Background: Narrow band imaging (NBI) is an innovative biological endoscopic technology designed to enhance the diagnostic precision by visualization of tumor-specific neo-angiogenesis. Currently available evidence indicates that narrow band imaging is a promising approach in the diagnosis of laryngeal cancer Methods: The descriptive study was conducted at the ENT outpatient department of Government Medical College, Ernakulam and Dept of Surgical Oncology at Cochin cancer Research Centre for a period of 6 months from August 2021 to January 2022 among 45 patients. The objective of current study was to assess the validity of narrow band imaging as a diagnostic and follow up tool in the diagnosis of laryngeal lesions and to study the epidemiological profile of different laryngeal pathologies. The findings in NBI i.e., type of vascular pattern was compared with histopathology findings. Results: Out of all the lesions, 33 (73.3%) were malignant and the location were glottis (40%), supraglottis (26.6%) and immediate subglottis (6.6%). White light endoscopy (WLE) was able to pick up only 27 cases as true positive, NBI alone was able to pick 32 cases as true positive while NBI with WLE was able to detect 33 true positive cases. At 95% confidence interval sensitivity of WLE was 81.8 % , NBI was 96.9% and of WLE with NBI was 100%. Specificity of WLE was 71.2%, NBI was 72.1% and WLE+NBI was 72.3%. PPV of WLE was 90.7%, NBI was 91.5% and of WLE+NBI was 92.6%. Negative predictive value of WLE was 55.3%, NBI was 78.9% and of WLE+NBI was 100%. Conclusion: The integration of Narrow Band Imaging (NBI) with White Light Endoscopy (WLE) enhances the sensitivity for detecting laryngeal malignancy and its precursor lesions. NBI is also beneficial for follow up in premalignant lesions, certain benign lesions and irradiated larynx.