Abstract

Laser-induced fluorescence (LIF) spectroscopy has received considerable attention as an application of lasers and fiberoptics to noninvasive tissue diagnosis, particularly in early detection of cancer in the breast¹, lung^1,2, esophagus³, and colon^4-7. LIF spectroscopy is currently under study as a noninvasive method of tissue diagnosis in the colon due to its potential for future routine application in gastrointestinal endoscopy. The distinction of normal colon from premalignant and malignant lesions is of potential clinical importance because the early detection of these lesions is important in the treatment of patients. Previously published analyses of ultraviolet LIF spectral and intensity differences have correctly differentiated adenomas from normal colonic mucosa and hyperplastic polyps with resulting sensitivity, specificity, and PPV of 80-100%, 77-95%, and 82-94%, respectively^4-7. Although these initial studies have provided compelling evidence supporting the use of LIF spectroscopy in early colon cancer diagnosis, there remains little information available regarding the specific origins and biochemical correlates of LIF spectra in colonic tissue. Proposed theories for the source of LIF differences in the colonic polyp model have included changes in gross polyp morphology⁷, microvascular changes⁷, differences in crypt architecture⁸, and biochemical differences characteristic of dysplastic epithelial cells⁸.

© 1996 Optical Society of America