Narrow Band Imaging Technology: Role in the Detection of Recurrent Laryngeal and Hypopharyngeal Cancers Post-radiotherapy

To assess the diagnostic accuracy of NBI endoscopy for the diagnosis of early recurrent laryngeal and hypopharyngeal cancers after radiotherapy. The study was conducted over a period of two and a half years from June 2019 to February 2022 and included 123 post-RT patients with laryngeal and hypopharyngeal cancers. The patients were planned for endoscopy with white light and narrow-band imaging. The biopsy was carried out in NBI suspected lesions and sent for histopathological examination. The pathologist was blinded to the outcome of NBI and WLE results to eliminate observer bias. The age group most commonly affected in our study was 40–50 years. Out of the 123 patients, 106 were males and 17 were females. The overall Sensitivity, Specificity, Positive predictive value and Negative predictive value of NBI for malignant lesions were 90.6%, 99%, 95.2% and 98% respectively. NBI Technology is a first-rate diagnostic tool that can help in diagnosing early recurrent cancer lesions, especially after RT, in which the recurrence is otherwise difficult to differentiate from post-radiotherapy oedema. This technology can significantly reduce the rates of failure to detect cancers in early stages.