Diagnostic accuracy of in vivo early tumor imaging from probe-based confocal laser endomicroscopy versus histologic examination in head and neck squamous cell carcinoma.

Probe-based confocal laser endomicroscopy (pCLE) is a noninvasive and real-time imaging technique allowing acquisition of in situ images of the tissue microarchitecture during oral surgery. We aimed to assess the diagnostic performance of pCLE combined with patent blue V (PB) in improving the management of early oral cavity, oro/hypopharyngeal, and laryngeal cancer by imaging squamous cell carcinoma in vivo. The prospective study enrolled 44 patients with early head and neck lesions. All patients underwent white-light inspection or panendoscopy depending on the lesion’s location, followed by pCLE imaging of the tumor core and its margins after topical application of PB. Each zone imaged by pCLE was interpreted at distance of the exam by three pathologists blinded to final histology. Most imaged zones could be presented to pathologists; the final sensitivity and specificity of pCLE imaging in head and neck cancers was 73.2–75% and 30–57.4%, respectively. During imaging, head and neck surgeons encountered some challenges that required resolving, such as accessing lesions with the flexible optical probe, achieving sufficiently precise imaging on the targeted tissues, and heterogeneous tissue staining by fluorescent dye. Final sensitivity scores were reasonable but final specificity scores were low. pCLE zones used to calculate specificity were acquired in areas of tumor margins, and the poor quality of the images acquired in these areas explains the final low specificity scores. Practical adjustments and technical training are needed to analyze head and neck lesions in various anatomical sites in real-time by pCLE.