裸鼠胃癌移植瘤的近红外荧光成像

目的：通过对非特异性探针Cy5.5在裸鼠体内分布及显像研究,探讨近红外荧光成像对胃癌的早期诊断及动态监测价值。方法：用MGC-803细胞株建立胃癌动物模型,进行早期、实时活体及离体显像实验。结果：近红外荧光成像可检测早期胃癌移植瘤的平均大小为2.807mm×3.045mm,与游标卡尺测得的肿瘤大小呈直线相关,r=0.924,P〈0.05。Cy5.5主要分布在肿瘤组织,主要代谢器官为肾脏;注入探针30min后,裸鼠肿瘤部位成像清晰,荧光寿命、荧光强度均高于对照部位（P〈0.05）。60min后,肿瘤区的荧光强度始高于血液（P〈0.05）。90min时达峰值。肿瘤部位的平均荧光寿命为（3.1376±0.9894）ns,明显高于对侧部位（P〈0.05）。结论：近红外荧光成像可用于胃癌的早期诊断及瘤体的动态监测。

Near infra-red fluorescence imaging of gastric cancer in xenograft nude mice

Objective：To assess the value of near infra-red fluorescence imaging in early diagnosis and dynamic monitoring of gastic cancer by non-specific probe Cy5.5 distribution and imaging in nude mice.Methods：The BALB/C nude mice were inoculateed with MGC-803 gastric tumor cells and imaging in vivo and ex vivo were performed periodically.Results：The average diameter of gastric cancer xenograft tumor detected by near infra-red fluorescence imaging were 2.807 mm×3.045 mm,which was linear correlation with sliding caliper measurement r=0.924,P〈0.05.The Cy5.5 accumulated mainly in tumor and primarily cleared out by kidney.The tumors were clearly imaged,both the fluorescent intensity and lifetime were higher than the contrast site at 30 minutes after injection of molecular probe（P〈0.05）.The fluorescent intensity started higher than blood after 60 minutes and became the highest afer 90 minutes.The average fluorescent lifetime of tumor was（3.1376±0.9894） ns,which was higher than the contrast site （P〈0.05）.Conclusion：Near infra-red fluorescence imaging is an effective way to early diagnose and monitor gastric cancer.