B-P-12
BIOMEDICAL PHOTONICS
Development of a multimodal approach to the diagnosis of human skin
cancer in vivo
I. A. Serebryakova12, Yu. I. Surkovu, E. N. Lazareva12, Y. K. Kuzinova3, O. M. Konopatskova3, V.V. Tuchin1'2'4
E. A. Genina12
1 - Saratov State University, Astrakhanskaya str. 83, Saratov, 410012, Russia 2 - Tomsk State University, Lenin's av. 36, Tomsk, 634050, Russia 3 - Saratov State Medical University, Bolshaya Kazachia str., 112, Saratov, 410012, Russia 4 - Institute of Precision Mechanics and Control RAS, Rabochaya str. 24, Saratov, 410028, Russia
e-mail: s.izabell2014@gmail.com
This work describes a newly developed multimodal method that has the potential to differentiate various skin neoplasms at an early stage of development, allows for postoperative monitoring to detect relapse, and provides additional information useful for selecting treatment tactics. A comprehensive non-invasive method is proposed to search for the specific markers of human skin neoplasms. The method includes: high-frequency ultrasound (US), optical coherence tomography (OCT), backscattering and Raman spectroscopy. In addition, the possibility of increasing the depth of OCT visualization using skin optical clearing was tested.
The study involved 21 volunteers (42 - 80 years old) of both sexes with slightly pigmented skin diagnosed with of basal cell carcinoma (BCC) or benign neoplasm (BN). Areas with neoplasms and nearby healthy and/or symmetrically located skin areas were selected as the object of the study for the subsequent comparison and evaluation of deviations from the norm.
As an optical clearing agent, a aqueous 40% glycerol solution was used, which was applied to the area of interest during 10 minutes.
The sizes of neoplasms were evaluated using US examination. In the OCT images of BCC and BN, in comparison with healthy skin, an inhomogeneous increase of the thickness of the epidermis up to two times was observed, the contrast of the epidermis-dermis border was significantly reduced, in some cases the border between the epidermis and the dermis was indistinguishable. In addition, there was an increase in the number of optical inhomogeneities, some of which can be attributed to blood and lymph microvessels, while others can be attributed to the areas of necrosis and, possibly, local areas of dissociated collagen.
As a result of the analysis of spectral data, one can observe the changes in pigmentation, blood saturation, a decrease in the diffuse scattering coefficient of the skin in the area under study and change in the slope of the spectrum, compared with visually healthy skin. For cancer, a characteristic feature was a low content of lipids and keratin. In the area of benign neoplasms, increased content of proteins, nucleic acids, lipids, and keratin was observed.
Thus, a multimodal approach to the study of skin neoplasms made it possible to obtain comprehensive information on BCC and DN: the boundaries of neoplasm, tissue microarchitecture, effective coefficients of melanin pigmentation and erythema, coefficient of spectral slope k, and coefficient of malignancy R, calculated from backscattering spectra. A multimodal approach to the diagnosis of BCC and DN may have greater sensitivity and specificity than each method to the study of skin neoplasms separately.
The reported study was funded by the grant of RFBR (#20-52-56005) and the grant under the Degree of the Government of the Russian Federation No. 220 of 09 April 2010 (Agreement No. 075-15-2021-615 of 04 June 2021).
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