5-ALA Mediated Fluorescence Detection of Gastrointestinal Tumors

Correspondence should be addressed to Ekaterina Borisova, borisova@ie.bas.bgReceived 7 March 2008; Revised 7 May 2008; Accepted 19 June 2008Recommended by Stoyan TanevDelta-aminolevulinic acid/protoporphyrin IX is applied for uorescent tumor detection in the upper part of gastrointestinal tract.The 5-ALA is administered per os six hours before measurements at dose 20mg/kg weight. High-power light-emitting diodeat 405nm is used as an excitation source. Special opto-mechanical device is built to use the light guide of standard video-endoscopic system. Through endoscopic instrumental channel a ber is applied to return information about uorescence tomicrospectrometer. In such way, 1D detection and 2D visualization of the lesions’ uorescence are received, and both advantagesand limitations of these methodologies are discussed in relation to their clinical applicability. Comparison of the spectra receivedfrom normal mucosa, inammatory, and tumor areas is applied to evaluate the feasibility for development of simple but eectivealgorithm based on dimensionless ratio of the uorescence signals at 560 and 635nm, for dierentiation of normal/abnormalgastrointestinal tissues.Copyright © 2008 Ekaterina Borisova et al. This is an open access article distributed under the Creative Commons AttributionLicense, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properlycited.