Ex Vivo Assessment of Keratinocytic Carcinomas Using a Fast Mid-Infrared Probe

A fast mid-infrared spectral probe was used to record infrared (IR) spectra of fresh skin tissue removed from patients with biopsy-proven keratinocytic cancer (KC) during Mohs surgery. A 150-patient library of IR spectral data was obtained to see if KC on the epidermal side (outside) of tissue samples can be differentiated from adjacent nonmalignant tissue and normal skin. A linear support vector machine model minimized overtraining predicting the contributions to decisions at each step in the spectrum. Training with an equal cost for KC and nontumor cases samples demonstrated a KC sensitivity of 93% ± 5% and specificity 82% ± 6% (threefold testing esd) on the full library. Success in this test problem warrants future studies to see if differentiation of melanoma from benign melanocytic as well as other skin lesions is possible on live skin. This study was approved by the Advarra Institutional Review Board, #PRO00053468.