ULTRAVIOLET LASER-INDUCED FLUORESCENCE OF HUMAN STOMACH TISSUES - DETECTION OF CANCER TISSUES BY IMAGING TECHNIQUES

Background and Objective: The background for this work was several Lit erature reports on applications of the fluorescence methods to detecti on and localization of human cancers. The objective of our study has b een to investigate if such an approach could be applied for the detect ion of gastric cancers. Study Design/Materials and Methods: Our study was designed in such a way that spectrally resolved images of laser-in duced fluorescence of human gastric mucosa were collected and assessed from a point of view of elaborating an algorithm allowing for a diffe rentiation between malignant and premalignant lesions and areas of nor mal mucosa. The method involved exciting the autofluorescence with ult raviolet light (325 nm, He-Cd laser). The images were recorded in vitr o in six regions of a visible spectrum using a cooled CCD camera. The material for study was 21 resected specimens for which altogether 72 s urface areas were examined. Results: The main result is the observatio n that a difference of the fluorescence intensities measured at 440 nm and 395 nm, both normalized to intensity measured at 590 nm, differs significantly for the tissues of interest. Conclusion: Using that diff erence as a diagnostic parameter, it was possible to classify malignan t tumor tissues with a sensitivity of 96% and a predictive value of 42 %, whereas the same approach applied to abnormal but not tumor stomach tissues gave values of 80% and 98%, respectively. (C) 1997 Wiley-Liss , inc.