Confocal fluorescence endomicroscopic imaging of the tongue

Confocal endomicroscopy is a novel, noninvasive microscopic technique that enables surface and subsurface imaging of living tissues or cells in vivo. This study was to explore the possibility of utilizing a novel rigid confocal endomicroscope (RCE) system for detecting morphological changes in living normal and neoplastic human and murine tongue tissue in combination with different photosensitizers, i.e. hypericin and 5-aminolevulinic acid (ALA) induced endogenous protoporphyrin IX (PPIX) fluorescence. Subjects were topically or systemically applied photosensitizer to the oral mucosa, and then fluorescence confocal endomicroscopy was performed on the tongue using the RCE system with the laser excitation wavelength at 488 nm. The preliminary results showed that confocal fluorescence images of the tongue can be acquired in real-time with well-defined micro-morphological structures, and changes of tissue structures associated with cancer transformation can also be identified. This study suggests that photosensitizer-mediated confocal endomicroscopy have a significant potential for rapid, non-invasive detection of early oral cancers in vivo.