Near-infrared Raman spectroscopy for optical diagnosis of lung cancer.
Raman spectroscopy is a vibrational spectroscopic technique that can be used to optically probe the molecular changes associated with diseased tissues. The objective of our study was to explore near-infrared (NIR) Raman spectroscopy for distinguishing tumor from normal bronchial tissue. Bronchial tissue specimens (12 normal, 10 squamous cell carcinoma (SCC) and 6 adenocarcinoma) were obtained from 10 patients with known or suspected malignancies of the lung. A rapid-acquisition dispersive-type NIR Raman spectroscopy system was used for tissue Raman studies at 785 nm excitation. High-quality Raman spectra in the 700-1,800 cm(-1) range from human bronchial tissues in vitro could be obtained within 5 sec. Raman spectra differed significantly between normal and malignant tumor tissue, with tumors showing higher percentage signals for nucleic acid, tryptophan and phenylalanine and lower percentage signals for phospholipids, proline and valine, compared to normal tissue. Raman spectral shape differences between normal and tumor tissue were also observed particularly in the spectral ranges of 1,000-1,100, 1,200-1,400 and 1,500-1,700 cm(-1), which contain signals related to protein and lipid conformations and nucleic acid's CH stretching modes. The ratio of Raman intensities at 1,445 to 1,655 cm(-1) provided good differentiation between normal and malignant bronchial tissue (p < 0.0001). The results of this exploratory study indicate that NIR Raman spectroscopy provides significant potential for the noninvasive diagnosis of lung cancers in vivo based on the optic evaluation of biomolecules.
Huang
Zhiwei
Z
Photomedicine and Optics Research Laboratory, Cancer Imaging Department, British Columbia Cancer Research Centre, 601 West 10th Avenue, Vancouver, B.C. V5Z 1L3, Canada.
McWilliams
Annette
A
Lui
Harvey
H
McLean
David I
DI
Lam
Stephen
S
Zeng
Haishan
H
D000368:Aged; D005260:Female; D006801:Humans; D007259:Infrared Rays; D008175:Lung Neoplasms / Q000175:diagnosis*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013059:Spectrum Analysis, Raman / Q000295:instrumentation* / Q000379:methods