Near-infrared Raman spectroscopy detects lung cancer

Abstract

This work was to explore near-infrared (NIR) Raman spectroscopy for distinguishing tumor from normal bronchial tissue. A rapid NIR Raman system was used for tissue Raman studies. High-quality Raman spectra in the 700-1800 cm -1 range can be acquired from human bronchial tissues in vitro. Raman spectra differed significantly between normal and malignant tumor tissue, with tumors showing increased nucleic acid, tryptophan, phenylalanine signals and decreased phospholipids, proline, and valine signals than normal tissue. Raman spectral shape differences between normal and tumor tissue were also observed particularly in the spectral ranges of 1000-1100, 1200-1400, and 1500-1700 cm -1 , which are related to the protein and lipid conformations and CH stretching modes in nucleic acids. The ratio of Raman intensities at 1445 cm -1 to 1655 cm -1 provided good differentiation between normal and malignant bronchial tissue, suggesting that NIR Raman spectroscopy may have a significant potential for the noninvasive diagnosis of lung cancer in vivo based on optical evaluation of biomolecules.