A STUDY ON LASER-INDUCED AUTOFLUORESCENCE FROM COLONIC CARCINOMA

研究表明，激光照射能诱导组织产生自身荧光。用点组织荧光技术对正常粘膜和结肠腺瘤进行了鉴别。然而，荧光材料在组织中的定位尚未确定，这使得荧光光谱变化的解释模糊不清。本研究的目的是确定诱导荧光的组织学来源，并确定荧光衰减发生在结肠腺瘤组织中的原因。为此，对34例腺瘤和10例正常粘膜进行325 nm激光荧光测定。正常粘膜表面的荧光光谱显示峰值波长为450 nm。粘膜肌层和粘膜下层的荧光光谱在380 nm和440 nm处呈双相峰长。450 nm处的峰值强度在连续激光照射10秒后没有降低，而380和440 nm处的峰值强度在连续激光照射10秒后衰减到初始强度的70%以下。这些发现表明这三种荧光成分是由特定结肠层的三种不同的荧光粉引起的。腺瘤表面的荧光光谱在450nm处也具有相同的峰值波长。而峰值强度较正常粘膜减弱至不足1/2。发现峰值强度与发育不良粘膜的大体形态或粘膜厚度无关。粘膜下层的荧光对观察到的荧光没有影响。与正常粘膜相比，腺瘤表面的峰值强度减弱可能是由于固有层的荧光物质减少。

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.