Dynamic real-time optical microscopy of oral mucosal lesions using confocal laser endomicroscopy

Abstract

Objectives: Confocal laser endomicroscopy (CLE) is a novel non-invasive point-of-care optical biopsy technology that enables real-time in vivo microscopic visualisation of cellular and tissue architecture. In this study, we assessed the diagnostic accuracy of a hand-held fluorescence single-fibre distal-scanning CLE (fsdCLE) platform for diagnosing oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC).

Materials and methods: Forty-seven patients presenting with 63 distinct oral mucosal lesions were subjected to optical biopsy using a miniaturised fsdCLE system (ViewnVivo®, Optiscan Imaging Ltd) and topical exogenous acriflavine hydrochloride contrast agent before undergoing tissue biopsy and histopathological consensus review by four pathologists. CLE images were captured in vivo in real-time during clinical examination and assessed on-the-fly for the presence of cellular and architectural features of OED/OSCC offering an instantaneous diagnosis. Predicted optical diagnoses were compared to definitive consensus tissue histopathology. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were calculated for the presence/absence of dysplasia/malignancy on optical biopsy. Percentage agreement, Fleiss' kappa, and intraclass correlation coefficient (ICC) were calculated for each assessment stage during the consensus histopathology process.

Results: Diagnostic accuracy was extremely high at 88.9%. Other metrics were sensitivity 86.8%, specificity 92%, PPV 94.3% and NPV 82.1%. One hundred percent of carcinoma cases were detected accurately using CLE in the clinic.

Conclusion: fsdCLE is a highly accurate, easy-to-use, rapid and slide-free point-of-care in vivo optical technology for diagnosing OED/OSCC and discriminating between dysplastic and non-dysplastic pathology. It demonstrates near-perfect agreement with traditional consensus histopathology without the need for physical tissue biopsy.

Keywords: confocal laser endomicroscopy; on-the-fly diagnosis; optical biopsy; oral epithelial dysplasia; oral squamous cell carcinoma.