The purpose of this study is to perform a preliminary evaluation of the diagnostic potential of laser-induced autofluorescence spectroscopy for colonic tumors using fluorescence intensity ratios at specific wavelengths. Measurements were made on normal mucosa and adenocarcinoma of human colon tissues. Each tissue section was examined using an optical probe consisting of a central fiber for delivering the excitation laser and a fiber bundle for detection of the fluorescence. Using different wavelengths of a CW mixed-gas laser, we measured and analyzed the LIAF spectra of tissues through a polychromator coupled with a CCD detector. It can be found that in the range of 520-620 nm, the spectral shapes of tumor tissues are very similar to the normal tissue spectra, and the autofluorescence intensities of normal tissues are about threefold higher than those of tumor tissues. However, in the range of 625- 720nm, the autofluorescence intensities of tumor tissues are higher than those of normal tissue. The spectral characteristics peaks arising from endogenous porphyrins can be observed in some tumor tissues. The preliminary results show that the autofluorescence intensity ratio of I₅₈₀/I₆₃₀ or I₅₈₀/I₆₈₀ can be used to distinguish colonic tumors from normal tissues with good accuracy.

Date Published: 16 April 1998
PDF: 6 pages
Proc. SPIE 3250, Optical Biopsy II, (16 April 1998); doi: 10.1117/12.305382

Published in SPIE Proceedings Vol. 3250:
Optical Biopsy II
Robert R. Alfano, Editor(s)