Optical Biopsy of Amelanotic Melanoma with Raman and Autofluorescence Spectra Stimulated by 785 nm Laser Excitation

Abstract

In this work, Raman and autofluorescence spectroscopy in the near-infrared region has been used for examining amelanotic melanoma as the most dangerous type of malignant melanoma. There were 9 patients with amelanotic melanoma, 60 with pigmented melanoma and 120 with basal cell carcinoma enrolled in this study. We studied 9 amelanotic melanoma cases to differentiate them from basal cell carcinoma (n = 120) and pigmented malignant melanoma (n = 60) using portable spectroscopy setup with laser excitation source at 785 nm and low-cost spectrometer. The spectra of the different tumor type were classified using projection on the latent structure analysis with 10-Fold cross-validation. The results of the tumor classification were presented using box-plot diagrams and ROC analysis. We obtained 0.53 and 0.88 ROC AUCs for distinguishing amelanotic melanoma versus (1) pigmented melanoma and (2) basal cell carcinoma respectively based on the joint autofluorescence and Raman spectroscopy analysis that allowed one to diagnose amelanotic melanoma as true melanoma but no basal cell carcinoma.

Laser Applications for Estimation of Microbial Activity and Investigation of NIR Skin Autofluorescence

“…Undoubtedly, the number of collected signals is statistically very low, as well as relative concentration of melanin content in skin phototypes III and II does not provide strong scientific evidence to draw any conclusions. However, the obtained data is in quantitative agreement with earlier published papers available in literature [7][8][9][10][11]. Further in collaboration with Ekaterina Borisova at the Institute of Electronics, Bulgarian Academy of Sciences we have collected NIR AF signals from formalinized ex vivo skin lesion samples (Fig.…”

“…The local peak at ~910 nm most probably is attributed to the CCD etaloning effects and could be neglected for the analysis. Obtained AF spectral features (peaks at 840 nm and 850 nm) are in a good agreement with available literature data, fully described by I. Bratchenko et al [7] Normalization (Fig. 8) of AF spectra acquired from healthy in vivo skin demonstrates that all processed spectra are nearly equal.…”

Combination of Optical Biopsy with Patient Data for Improvement of Skin Tumor Identification

“…The detailed description of the experimental setup for simultaneous Raman and AF signal registration was presented in our previous studies [ 29 , 32 ]. The scattering spectral response from skin tissue in the near-infrared region was stimulated using a thermally stabilized diode laser module (LuxxMaster, LML-785.0RB-04, PD-LD, Ushio Inc., Tokyo, Japan) with 785 ± 0.1 nm central wavelength.…”

“…Raman spectroscopy has proved to be a sensitive research instrument in clinical practice for a number of purposes [ 24 , 27 , 30 , 31 ]. The proposed method [ 29 , 32 ] was able to classify skin neoplasms with a mean accuracy higher than the accuracy of general practitioners or trainees, and with comparable or less accuracy than trained dermatologists and experts. Therefore, it remains necessary to improve the accuracy of skin cancer diagnosis performed with Raman and AF analysis.…”

A review of career devoted to Biophotonics – In memoriam to Ekaterina Borisova (1978–2021)

“…Within this project, scientists from Sofia and Samara tried to combine optical techniques in order to increase the efficiency of skin cancer diagnosis. This collaboration provided an opportunity to perform joint studies of ex vivo tumors [102] and analyze the in vivo data collected both in Sofia and Samara [32], including data that helped to detect such rare tumor as amelanotic melanoma [103]. During her short visit to Samara (November 2019) Assoc.…”