Abstract:
Vibrational optical coherence tomography (VOCT) is a new technique to optically image and measure the resonant frequency of cells, blood vessels, papillary collagen, and fibrotic tissue in the skin and other soft tissues. The technique uses low levels of infrared light (0.1mW) for imaging and audible sound (55dB) to vibrate the tissue to evaluate the effects of physical forces on tissue deformation. It is well known that cancer cells and cancerous tissue are stiffer than normal skin and this difference can be used to quantitatively differentiate benign from cancerous lesions. While optical coherence tomography (OCT) is used extensively in ophthalmology its use in dermatology is just beginning for lesion identification. VOCT can be useful to both the dermatologist and general practitioner to noninvasively evaluate the types, margins, and depths of skin lesions. While conventional OCT provides an image of the tissue, VOCT provides images of tissues as well as quantitative physical data that can be used in concert with machine learning to assist in diagnosis and understanding of the pathophysiology of skin cancers. Results of studies on normal skin indicate that cells, blood vessels, and papillary collagen have resonant frequencies of 50, 100, and 150 Hz, respectively. Additional resonant frequencies at 80, 130, and 250-260 Hz are seen in cancerous lesions, corresponding to cancer associated fibroblasts, new thin blood vessels and fibrotic tissue, respectively. This talk will summarize the results of clinical studies using VOCT data and machine learning to characterize the differences between normal skin, basal cell carcinomas, squamous cell cells carcinomas, seborrheic keratoses, and melanomas yielding specificities and sensitivities approaching and exceeding 90%. In addition, a comparison is made between the histopathology and OCT images identifying the relationship between morphologies seen by histopathology and those seen in OCT images. The results of these studies suggest that VOCT in conjunction with visual inspection and dermoscopy can be used noninvasively to screen patients for skin cancers. The ability to use VOCT over the internet makes it useful in the remote screening of skin lesions using telemedicine.
