Advances in oral cancer detection using optical coherence tomography

In vivo imaging in the oral cavity by endoscopic optical coherence tomography

“…[1][2][3][4] Even though OCT does not deliver subcellular resolution or molecular contrast, it has the potential of label-free optical biopsies of tissue in vivo by a simple noninvasive subsurface view to assess depth structures of oral soft and hard tissue lesions. Most research has presented the feasibility of OCT in various preclinical animal [5][6][7] and human [8][9][10] oral cavity studies. Although OCT enables functional imaging, such as Doppler OCT, [11][12][13] polarization-sensitive OCT [14][15][16] and spectroscopic OCT, 17,18 the core strength of oral examination by OCT convincingly lies in the easily applied morphological imaging valued by a physician similar to US examinations.…”

“…OCT provides assessment of the entire epithelium and partly the underlying lamina propria (LP) and has the potential to distinguish normal from pathologic mucosal tissue of different entities. 5,6,[35][36][37][38][39] The distinction between normal and pathologic tissue is mainly based on the measurement of the epithelial thickness, the identification of the adjacent basement membrane, and the vasculature within the LP, as well as the changed backscattering behavior of the altered tissue lesions. The most promising approach in this context is the potential for biopsy guidance by OCT in conjunction with an improvement of diagnostic accuracy of biopsies.…”

The use of optical coherence tomography and convolutional neural networks to distinguish normal and abnormal oral mucosa

“…For instance, Raman spectroscopy, which relies on the inelastic scattering of monochromatic light that probes molecular bond vibrations, creates a biochemical "fingerprint" of the target tissue. [8,31,32] However, the Raman signals are very weak and often requires a lengthy integration period of 20 seconds to several minutes for one frame, making it an inaccessible tool for real time usage.…”

“…These technologies could potentially be used in situ, as well as in specimens that have been freshly resected. [4,7,8] Of the aforementioned imaging modalities, OCT is unique in that it provides real-time cross-sectional images at near histopathological resolution. Analogous to ultrasound, OCT relies on the changes or differences in tissue optical properties (chiefly changes in tissue refractive index) to generate high-resolution anatomically stratified images.…”

“…OCT has been shown to differentiate normal and abnormal oral mucosa. [4,[8][9][10][11][12][13][14][15][16] However, direct subjective interpretation of OCT images by human observers requires extensive training. [11] Since contemporary OCT systems may acquire more than 40 images/second, the overwhelming amount of data generated poses a challenge for clinical interpretation.…”