激光诱发荧光与大肠癌的诊断

Laser-induced fluorescence and colorectal cancer diagnosis

目的 研究激光诱发荧光 (LIF)技术在大肠癌早期诊断中的作用 ,并对LIF光谱产生的机制进行初步的探讨。方法 1.以氮分子激光器作为激发光源 ,采用OMAⅢ对体外 60例标本及体内 83例患者病变组织与正常组织的LIF光谱进行记录、分析。 2 .应用激光共聚焦扫描显微镜检测组织各层荧光强度。结果 1.根据体内、外LIF光谱的特点 ,选择主峰强度 (x1)、I 4 0 0nm/I 5 3 0nm(x2 )和集成荧光强度 ( 3 5 0～ 60 0nm) (x3 )三个参数 ,对已知病变求得判别方程 ,利用该方程对未知病变进行分析 ,体外诊断大肠癌的敏感性和特异性分别为 89.3 6%和 87.64 % ,体内为 83 .3 3 %和 94 .3 8% ,伴有中～重度不典型增生的腺瘤性息肉 87.10 % ,判别为异常。 2 .激光共聚焦扫描显微镜检测结果显示正常组织粘膜下层及肌层荧光较强 ,而正常组织粘膜层与癌组织的荧光均较弱 ;正常粘膜上皮脱落细胞与癌细胞可以产生荧光 ,但光谱强度均较弱。结论 1.LIF光谱可以在体内、外区别大肠癌组织与正常组织 ,尤其是对不典型增生的鉴别能力较强 ,提示该技术对于大肠癌的早期诊断具有非常重要的意义。 2 .正常组织LIF光谱的来源主要是胶原含量丰富的粘膜下层 ,而癌组织的光谱可能是癌细胞与间质共同作用的结果。

Objective To study the effect of laser induced fluorescence(LIF) on the early diagnosis of colorectal cancer and to analyze the mechanism of the production of LIF spectrum. Methods 1. A nitrogen laser was used as a stimulating light source. An optical multichannel analyzer (OMA Ⅲ) was used to analyze emission spectrum of the fluorescence in 60 patients with colorectal cancer in vitro and 83 patients in vivo, respectively. 2. The samples were frozen and 80～100μm thick frozen sections were cut perpendicularly to the mucosal surface in a cryostat, comprising mucosa, submucosa and muscularis, the sections were then studied by confocal laser scanning microscopy. Result 1. The emission spectrum of LIF recorded in colorectal cancer and normal tissue showed significant differences in single amplitude of main peak and spectrum shape both in vitro and in vivo. The sensitivity and specificity of LIF for diagnosis of colorectal cancer were 89.36% and 87.64% in vitro, 83.33% and 94.38% in vivo, respectively. 87.10% of dysplasia were regarded as abnormal. 2. The fluorescence mainly came from the submucosa in normal colon and the intensity of fluorescence of the mucosa in normal and cancer tissue were modest. Conclusion 1. Both in vitro and in vivo, the LIF spectrum can be used to distinguish colorectal cancer from normal colon tissue, especially the dysplasia. 2. The submucosa plays an important role in the emission spectrum in the normal tissue, and the spectrum of cancer is attributed to both cancer cells and intercellular substance.