Polarized Raman Microspectroscopy Can Reveal Structural Changes of Peritumoral Dermis in Basal Cell Carcinoma

Abstract

Polarized Raman microspectroscopy can provide precious information regarding the orientation and ordering of the molecules in a sample without staining or particular preparation. This technique is used for the first time on a human skin section to probe the molecular modifications of the surrounding dermis in superficial basal cell carcinoma. Spectra using polarized and conventional Raman microspectroscopies were recorded on dermis bordering either the tumor or healthy epidermis. Band areas and spectral decomposition on selected vibrations were computed. Significant differences in dermal collagen vibration bands are detected using both polarized and conventional micro-spectroscopies, but the spectral changes between tumor and healthy tissues are enhanced using polarized Raman microspectroscopy. The analysis of these spectral differences highlights structural modifications of the triple helix of collagen. We see polarized Raman microspectroscopy as a potential tool that could be implemented for clinical analyses to guide clinicians and surgeons in the treatment of aggressive skin cancers. The information obtainable could also help better elucidate the molecular mechanisms induced in basal cell carcinoma development.

Age-related changes in molecular organization of type I collagen in tendon as probed by polarized SHG and Raman microspectroscopy

“…Indeed, they have demonstrated the potential of this technique to obtain multiscale information on collagen at molecular level as well as on spatial orientation of collagen fibers. This technique has been also used successfully for cancer diagnosis based on collagen analysis 20,30,31 and orientation of collagen fibers during skin aging 32,33 . A previous work has also demonstrated the advantage of PRS, when compared to conventional Raman spectroscopy, to better discriminate normal from tumor tissues 34 .…”

Optical design for laser tweezers Raman spectroscopy setups for increased sensitivity and flexible spatial detection

“…In this configuration, the PBS acts as a beam combiner and analyzer to selectively combine the polarized and depolarized Raman bands. As a demonstration, we add a half-wave plate to the forward-scattered beam path and use it to rotate the polarization by 90 • and measure the Raman spectrum of cyclohexane, a chemical with a know polarization dependence [23]. From this measurement, we can see a polarization dependence on the ∼800 cm −1 peak and the small peak at ∼1030 cm −1 , as they have strongly reduced intensities in the forward-scattered spectrum [Fig.…”

Raman spectroscopy: Incorporating the chemical dimension into dermatological diagnosis

“…[ 50 ] Polarized Raman microspectroscopy has been used to monitor peritumoral changes in the stroma. [ 51 52 ] Though subtle, these changes can differentiate the peritumoral dermis in superficial and nodular BCC from normal, healthy dermis. In discriminating tumoral, nontumoral and peritumoral areas in skin sections, Raman spectroscopy could expedite Mohs excision of a tumor by providing a real-time intraoperative determination of tumor borders.…”