Validation of Narrow Band Imaging in Recurrent Respiratory Papillomatosis Using Severity Scales

To validate the diagnostic utility of narrow-band imaging (NBI) compared with white-light imaging (WLI) in assessing recurrent respiratory papillomatosis (RRP) across three scoring systems (Derkay, Dikkers, and the Numerical RRP Scale) and to evaluate convergence between them.

Between September 2023 and December 2024, 16 adults with severe RRP were enrolled at the Wroclaw Regional Specialist Hospital. All underwent microlaryngeal surgery with intralesional bevacizumab injections. Prior to each procedure, flexible transnasal videoendoscopy with WLI and NBI was performed. The presence and vascular characteristics of papillomas were documented. Disease severity was assessed at baseline, following each injection, and 6 months after the final treatment, yielding a total of 88 evaluations. Histopathological confirmation of RRP was obtained for all cases.

On WLI, papillomas appeared as raspberry-like, sessile or exophytic lesions. NBI consistently revealed intrapapillary capillary loops (IPCLs) with wide-angled turning points and centrally oriented axes. Scores from NBI and WLI correlated strongly across all systems. However, Derkay and Numerical scales yielded consistently higher values with NBI. The strongest correlation was between Derkay and Numerical scores (Pearson's r = 0.78). According to the Numerical scale, NBI led to a higher score in 24 out of 88 assessments (27.3%).

NBI provides reliable diagnostic enhancement in RRP and supports accurate differentiation of benign papillomatous lesions from premalignant vascular patterns. Its validation against established clinical scoring systems highlights its value as a standardized tool for disease monitoring and treatment planning.