Study of Non-Altered Colorectal Tissue by FT-Raman Spectroscopy

Abstract FT-Raman spectroscopy was employed to study (in-vitro) non-altered human colorectal tissues aiming evaluate their spectral differences. The samples were collected from 39 patients, adding 144 spectra. The results enable one estabilish 3 well defined spectroscopic groups of what was consistently checked by statistical (clustering) and biological (histopathology) analysis. The similarity within each group was better than 90%. Groups 1 and 2 had 80% of similarity while presenting both 70% of similarity to group 3. All groups presented connective and epithelial tissues as histopathological characteristic. Group 1 differs from others by the presence of soft muscle while group 3 by presence of fatty tissue. Tissues from group 2 are composed by samples with connective and epithelial tissues. This study is very relevant in order to establish the non-altered or normal spectroscopic standard for future studies and applications on optical biopsy and diagnosis of colorectal cancer.