摘要
目的研究S-^11C-甲基-L-半胱氨酸（^11C—MCYS）在荷Hepa 1-6肝癌小鼠体内的生物学分布及其在肿瘤PET显像中的价值。方法（1）荷Hepa1石肝癌小鼠25只，经尾静脉注射^11C—MCYS注射液1．48MBq，分别在注药后5、10、20、30和60min 5个时间点测量肿瘤组织及各器官的放射性，计算％ID／g。荷瘤小鼠10只，经尾静脉注射^11C—MCYS1．48MBq，分别于5、10、20、30和60min行全身PET／CT扫描，观察全身放射性分布及代谢睛况。（2）荷瘤小鼠及炎性反应小鼠模型各20只，经尾静脉注射^11C。MCYS1．48MBq，1h后行全身PET／CT扫描。通过ROI获得肿瘤和炎性反应组织的SUVmax，并计算肿瘤／肌肉、炎性反应组织／肌肉放射性比值。采用t检验进行统计分析。结果（1）^11C—MCYS在体内吸收迅速，给药后5max放射性分布即可达到高峰，5min时肝和肾放射性分布分别为（1．97±0．12）和（1．02±0．09）％ID／g，60min时肝和肾放射性摄取降为（0．53±0．14）和（0．29±0．05）％ID／g，而脑、肺、胃及肌肉等组织放射性摄取均小于（0．23±0．05）％ID／g，肿瘤组织放射性摄取为（0．48±0．05）％ID／g。荷瘤小鼠不同时间点PET显像示小鼠各脏器的放射性摄取与各相应时间点小鼠体内放射性分布一致。（2）肿瘤组织摄取^11C—MCYS较高，SUVmax为4．58±0．65，而炎性反应组织摄取^11C—MCYS较低，SUVmax为1．02±0．18，肿瘤／肌肉及炎性反应组织／肌肉的放射性比值分别为7．27和1．62，差异有统计学意义（t=2．906，P〈0．01）。结论”C—MCYS是一种有前景的新型氨基酸类PET显像剂，有望用于肿瘤与无菌性炎性反应的鉴别。
Objective To investigate the biodistribution of ^11C-methyl-L-cysteine （MCYS） in tumor bearing mice and its value in tumor PET imaging. Methods The samples of tumors and organs were taken from 25 mice at different time points （5, 10, 20, 30, 60 rain） after injection of 1.48 MBq ^11C-MCYS via tail vein. Radioactivities （counts per minute） were measured, and the % ID/g was calculated. PET/CT scans were performed in 10 HCC-bearing mice at 5, 10, 20, 30, 60 rain after the injection of 1.48 MBq ^11C- MCYS, and the whole body distribution and ^11C-MCYS metabolism were investigated. ^11C-MCYS （1.48 MBq） PET/CT imaging was also performed in another 20 HCC-bearing mice and 20 mice models of inflammation. The SUVmax and ratios of lesions to muscle were calculated by drawing ROIs. T-test was used to analyze data by SPSS 15.0. Results ^11C-MCYS was absorbed quickly. The %ID/g of ^11C-MCYS in liver and kidney was 1.97 ±0.12 and 1.02±0.09 at 5 min respectively, then gradually decreased to 0.53 ±0. 14 and 0. 29± 0.05, respectively, within 60 min after injection. ^11C-MCYS was metabolized through the liver and kidney. Low uptake of ^11C-MCYS （ 〈 （0. 23 ±0.05） % ID/g） was observed at 60 min after injection in the brain,lung, stomach and muscle. However, the uptake in the tumor was （0.48 ± 0.05 ） % ID/g. PET/CT images at different time points showed that the whole-body radioactive uptake was consistent with the corresponding biodistribution. There was higher accumulation of ^11C-MCYS in tumor than in muscle. The tumor-to-muscle and inflammatory lesion-to-muscle ratios were 7.27 and 1.62, respectively, at 60 min after injection （ t = 2.906, P〈0.01）. Conclusions ^11C-MCYS is a promising amino acid PET tracer. It may be helpful in the differentiation of tumor from aseptic inflammation with a potential clinical value.
出处
《中华核医学与分子影像杂志》
CSCD
北大核心
2012年第3期214-217,共4页
Chinese Journal of Nuclear Medicine and Molecular Imaging
