Fast Mid‐Infrared Spectral Probe Decisions Match H&E Stain Results for Keratinocytic Carcinoma

We designed a handheld and fast mid-infrared fiber-optic spectral probe using a quantum cascade laser (QCL) and a reduced range of wavelengths, to see if keratinocytic carcinoma (KC) could be distinguished from adjacent nonmalignant tissue using discarded skin tissues from Mohs surgery. This study employed two adjacent frozen sections of discarded tissue: one was stained with H&E (the gold standard for skin cancer diagnosis) to identify the location of cancer by a pathologist, while the other was left unstained for mid-infrared spectral probing on and off cancer as guided by the adjacent H&E stain. A total of 346 spectra from 18 consenting patients were collected during Mohs surgery. After adding a dehumidifier, an accuracy of 95% was obtained on a case sample basis. It will be worthwhile to assess the probe's utility at the surface of live human skin (study approved by the Advarra Institutional Review Board [PRO00044823]).