Raman spectroscopy has been well established as a powerful method for studying biological tissues and
diagnosing diseases. In this study we have developed a breast cancer animal model and collected in
vivo Raman spectra of mammary glands of 27 Sprague-Dawley female rats treated with DMBA and 5
non-treated used as control group. A dispersive Raman spectrometer with a @785 nm laser excitation
coupled a fiber optic probe and a CCD detector was used to obtain the spectra. The obtained in vivo
transcutaneous Raman spectra have shown important differences between normal and abnormal tissues
when acquired from one side to the other side of the lesion.
The Fourier transform (FT)-Raman spectroscopy technique is used to assess the biochemical alterations that occur in the degenerative process of the rotator cuff supraspinatus tendon. The main alterations observed occur in the glycine, proline, hydroxyproline, cysteine, cistine, phenylalanine, tyrosine, collagen I and III, nucleic acid, lipids, glycosaminoglycans, and metalloproteinases bands. An increasing intensity for these bands is found in degenerated tendons, a finding well correlated with hyaline state and cellular activity. Statistical analysis (principal components analysis and clustering) shows a clear separation of the spectra into nonhyalinized and hyalinized clusters, which enables the construction of a binary diagnosis model based on logistic regression. Best diagnosis provided a sensitivity of 66.0% and a specificity of 74.7% with 79.6% concordant pairs. The discriminating power of the diagnostic test is assessed by computing the area under the receiving-operator characteristic curve (AUC), which indicates good accuracy (AUC=0.81). In principle, these results indicate that Raman spectroscopy can be used as an auxiliary aid to improve shoulder tendon surgery quality by guiding anchoring onto more healthy (nonhyaline) pieces of tendons. This should contribute to a decrease in the current high rerupture rate (13 to 68%) for this procedure.