Bimodal spectroscopic evaluation of ultra violet-irradiated mouse skin inflammatory and precancerous stages: instrumentation, spectral feature extraction/selection and classification (k-NN, LDA and SVM).
Fiche publication
Date publication
juillet 2009
Auteurs
Membres identifiés du Cancéropôle Est :
Dr LEROUX Agnès, Dr AMOUROUX Marine
Tous les auteurs :
Diaz-Ayil G, Amouroux M, Blondel WCPM, Bourg-Heckly G, Leroux A, Guillemin F, Granjon Y
Lien Pubmed
Résumé
This paper deals with the development and application of in vivo spatially-resolved bimodal spectroscopy (AutoFluorescence AF and Diffuse Reflectance DR), to discriminate various stages of skin precancer in a preclinical model (UV-irradiated mouse): Compensatory Hyperplasia CH, Atypical Hyperplasia AH and Dysplasia D. A programmable instrumentation was developed for acquiring AF emission spectra using 7 excitation wavelengths: 360, 368, 390, 400, 410, 420 and 430 nm, and DR spectra in the 390-720 nm wavelength range. After various steps of intensity spectra preprocessing (filtering, spectral correction and intensity normalization), several sets of spectral characteristics were extracted and selected based on their discrimination power statistically tested for every pair-wise comparison of histological classes. Data reduction with Principal Components Analysis (PCA) was performed and 3 classification methods were implemented (k-NN, LDA and SVM), in order to compare diagnostic performance of each method. Diagnostic performance was studied and assessed in terms of sensitivity (Se) and specificity (Sp) as a function of the selected features, of the combinations of 3 different inter-fibers distances and of the numbers of principal components, such that: Se and Sp approximate to 100% when discriminating CH vs. others; Sp approximate to 100% and Se > 95% when discriminating Healthy vs. AH or D; Sp approximate to 74% and Se approximate to 63% for AH vs. D.
Référence
Eur Phys J-appl Phys. 2009 Jul;47(1):12707.