Novel Autofluorescence Imaging System Is Useful for Detection of Neoplastic Lesion in Colon Tumor

Abstract

Introduction: In development of fluorescence-based diagnostic technologies, new CCD and the image processor were developed by Olympus Medical System Co. Ltd., (Tokyo Japan). This system uses dedicated videoendoscope (XCF-H240FZI), which incorporates two charged coupled devices (CCD) for the autofluorescence (AF) and conventional white light (WL) mode. Methods: 90 colorectal lesions including nine cases of large hyperplastic polyps (more than 15 mm diameter), six of colon submucosal tumors (SMT), 32 of tubular adenomas and 43 early colon cancers were excised endoscopically or surgically, were analyzed in this study. 90 cases observed with AFI were evaluated retrospectively by two well-trained endoscopists. In addition, the brightness of magenta color of AFI imaging was divided into the following patterns; weakness, moderate and strength. It was analyzed whether the differences of fluorescence features between each lesion were determined by the location, macroscopic appearance and histology. Histological diagnosis was undertaken according to World Health Organization classifications. Results: All 75 epithelial neoplastic lesions were observed as the color of magenta whereas the normal background mucosa showed deep green (sensitivity and specificity 100%). In contrast, hyperplastic polyp and SMT were observed the same as the color of surrounding mucosa (15 cases). In macroscopic appearance, flat elevated lesion tended to show the more brightness, compared to the protruded lesion (100% VS. 92.6%). Therefore, the boundary of tumor was recognized clearly compared to the observation by WL (76.0%, 57/75 cases). The location of lesion could not determine the patterns of magenta. In histological findings, the brightness was similar at histological grading or depth of tumor invasion. Conclusion: AFI system was very easy to use, because the pushed one button change the light from WL to AF without complicated work. Therefore, it was useful for differential diagnosis between epithelial neoplasia and non-neoplasia. Especially, it might be easily able to distinguish between adenomatous lesion and hyperplastic polyp, because of the change to magenta color. We expect AFI system will enable the detection of flat elevated lesions more easily because of strong brightness of magenta, comparing with conventional WL mode observation.