Role of narrow band imaging in detecting recurrence in patients of squamous cell carcinoma larynx and hypopharynx who underwent radiotherapy/chemo-radiotherapy.

Narrow band imaging (NBI) is an emerging modality that enhances the accuracy of detection of head and neck malignancies by visualisation of aberrant neoangiogenesis in malignant tissue using narrow bandwidth light in blue and green spectrum. The purpose of this study was to assess the role of NBI in detecting recurrence in patients with Squamous cell carcinoma larynx and hypopharynx who have undergone Radiotherapy/Chemoradiotherapy (RT/CTRT). The aim of the study was to (a) determine the role of NBI in follow-up of patients with carcinoma of larynx and hypopharynx previously treated with radiotherapy or chemotherapy, (b) determine the role of NBI as the initial investigatory tool of choice in detecting local recurrence and compare with other modalities like fibreoptic laryngoscopy (FOL), Magnetic Resonance Imaging (MRI) and Positron Emission Tomography- Computed Tomography (PETCT). Prospective multicentric study at ENT departments of tertiary care centres in Delhi, Bangalore and Pune in India was conducted from Jan 2019 to Sep 2022. Thirty-four consecutive patients diagnosed as squamous cell carcinoma (SCC) larynx/hypopharynx who underwent chemo/radiotherapy were scheduled for NBI 12 weeks after completion of therapy with FOL and PETCT/MRI and followed up 03 monthly for 02 years. NBI/FOL/PETCT or MRI and Histopathological Examination (HPE) were compared. NBI was found to be 100% sensitive and 96% specific with a positive predictive value of 85% and negative predictive value of 100% respectively with a diagnostic accuracy of 97%. NBI along with FOL increases the sensitivity of detection of recurrence in patients of laryngeal/hypopharyngeal cancer post-chemo/radiotherapy. [ABSTRACT FROM AUTHOR]