Light-induced autofluorescence and diffuse reflectance spectroscopy in clinical diagnosis of skin cancer

Abstract

We investigated more than 500 clinical cases to receive the spectral properties of basal cell (136 patients) and squamous cell carcinoma (28), malignant melanoma (41) and different cutaneous dysplastic and benign cutaneous lesions. Excitation at 365, 385 and 405 nm using LEDs sources is applied to obtain autofluorescence spectra, and broad-band illumination in the region of 400-900 nm is used to detect diffuse reflectance spectra of all pathologies investigated. USB4000 microspectrometer (Ocean Optics Inc, USA) is applied as a detector and fiber-optic probe is used for delivery of the light.In the case of in vivo tumor measurements spectral shape and intensity changes are observed that are specific for a given type of lesion. Autofluorescence origins of the signals coming from skin tissues are mainly due to proteins, such as collagen, elastin, keratin, their cross-links, co-enzimes -NADH and flavins and endogenous porphyrins. Spectral features significant into diffuse spectroscopy diagnosis are related to the effects of re-absorption of hemoglobin and its forms, as well as melanin and its concentration in different pathologies. We developed significant database and revealed specific features for a large class of cutaneous neoplasia, using about 30 different spectral peculiarities to differentiate cutaneous tumors. Sensitivity and specificity obtained exceed 90%, which make optical biopsy very useful tool for clinical practice.These results are obtained in the frames of clinical investigations for development of significant "spectral features" database for the most common cutaneous malignant, dysplastic and benign lesions. In the forthcoming plans, our group tries to optimize the existing experimental system for optical biopsy of skin, and to introduce it and the diagnostic algorithms developed into clinical practice, based on the high diagnostic accuracy achieved.

Malignant melanoma and basal cell carcinoma detection with 457 nm laser-induced fluorescence

“…Comparison of achieved accuracy with other methods of melanomas detection gives ambiguous results. For example in [8] achieved accuracy of melanomas and non-melanoma skin cancers separation was 93.6%. But in research [8] AF analysis was supplemented with backscattered radiation analysis.…”

“…For example in [8] achieved accuracy of melanomas and non-melanoma skin cancers separation was 93.6%. But in research [8] AF analysis was supplemented with backscattered radiation analysis. Joint application of two spectroscopic techniques increased the information rate of AF study, while only AF analysis provided about 60 -80% accuracy of cancers separation that is quite close to the results of current study (for example BCC separation in [21] or overview [22]).…”

“…The combined diagnostic methods help to scan large tissue areas using autofluorescence (AF) or backscattering analysis for large tissue areas scanning with subsequent RS examination of suspicious tissues [6,7]. The applicability of the AF methods for skin cancer analysis in visible and near infrared (NIR) regions has been demonstrated in many studies [8,9]. But overall accuracy of AF implementation still remains under consideration.…”

Mobile phone based mini-spectrometer for rapid screening of skin cancer

“…We have also explored coupling the spectrometer to a dermatoscope in order to carry out visual as well spectral examination of the skin. There have been reports that endogenous fluorescence from skin can be used to distinguish between cancerous and non-cancerous lesions [4,5] and also provide markers for aging [6]. We attempt to use the spectrometer-dermatoscope combination to rapidly screen for skin cancer.…”

Combined autofluorescence and Raman spectroscopy method for skin tumor detection in visible and near infrared regions

“…The combined diagnostic method helps to scan large tissue areas using autofluorescence (AF) or backscattering analysis of the scanning tissue with subsequent RS examination of suspicious tissue areas 7,8 . The applicability of the AF methods for skin cancer analysis in visible and near infrared (NIR) regions has been demonstrated in many studies 9,10 . In current work we demonstrate possibility of application of RS, AF and their combination in visible and NIR regions to improve the sensitivity and specificity of skin tumors diagnosis.…”