A STUDY ON LASER-INDUCED AUTOFLUORESCENCE FROM COLONIC CARCINOMA

1998 Fiscal Year Final Research Report Summary

• Project/Area Number: 09557049
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 展開研究
• Research Field: Gastroenterology
• Research Institution: HIROSAKI UNIVERSITY
• Principal Investigator: MUNAKATA Akihiro SCOOL OF MEDICINE PROFESSOR, 医学部, 教授 (50003661)
• Co-Investigator(Kenkyū-buntansha): SASAKI Yoshihiro UNIVERSITY HOSPITAL INSTRUCTOR, 医学部・附属病院, 助手 (70178672) ; UNO Yoshiharu UNIVERSITY HOSPITAL INSTRUCTOR, 医学部・附属病院, 助手 (50271812) ; FUKADA Shinsaku UNIVERSITY HOSPITAL ASSOCIATE PROFESSOR, 医学部・附属病院, 助教授 (60261450)
• Project Period (FY): 1997 – 1998
• Keywords: Fluorescence / Spectroscopy / Endoscopy

Research Abstract

It has been shown that laser irradiation is able to induce autofluorescence from tissues. Point tissue fluorescence has been investigated to distinguish normal mucosa from colonic adenoma. While, the localization of fluorescent materials in the tissue has not been necessarily established, which made the interpretation of changes in fluorescence spectra obscure. The aim of this study was to determine the histological origin of induced fluorescence and to determine the cause of fluorescence attenuation occurring in the tissue of colonic adenoma. For this purpose, 325 nm-laser fluorimetry was performed by using 34 adenomas and 10 normal mucosa. Fluorescence spectrum form the normal mucosal surface exhibited a peak wave length at 450 nm. While, fluorescence spectrum form the muscularis mucosae or submucosa had biphasic peak length at 380 and 440 nm. A peak intensity at 450 nm was not reduced by a continuous laser irradiation of 10 sec, while those at 380 or 440 nm decayed to less than 70 % of the initial intensities by irradiation of 10 sec. These findings suggest that the three orescence components are attributed to three different phosphors in specific colonic layer. Fluorescence spectra from the surface of adenoma had also the same peak wave length at 450 nm. While, peak intensity was attenuated to less than 1/2 of that from the normal mucosa. The peak intensity was found to be not correlated with gross morphology of dysplastic mucosa, or the mucosal thickness. Furthermore, the fluorescence in the submucosa did not influence on the observed fluorescence. The attenuated peak intensity from the surface of adenoma may be attributed to reduced fluorescent material in the lamina propria compared with the normal mucosa.