^11nC-乙酸盐制备方法的改进及生物体内分布  

Improvement of the synthesis Of ^11C-acetate and its biological evaluation

作　　者：霍力[1] 周前[1] 傅喆[1] 

机构地区：[1]中国医学科学院北京协和医学院北京协和医院核医学科PET中心,100730

出　　处：《国际放射医学核医学杂志》2008年第4期193-196,共4页International Journal of Radiation Medicine and Nuclear Medicine

摘　　要：目的改进美国CTI公司^11C-乙酸盐（^11C—AC）自动合成模块流程，提高产量稳定性；用小鼠体内分布、小鼠和正常人体显像验证改进后产品的性能。方法1．^11C—AC的制备：猝灭反应水量由原来的0．1-0．2ml固定在0．2ml；除杂质和蒸馏温度由135℃提高至145℃；薄层层析法检测放射化学纯度。2．改进后产品性能的验证：（1）体内分布：20只雌性小鼠随机分4组，静脉注射^11C—AC后0．5min、5min、10min和20min处死，计算血及脏器的每克组织的百分注射剂量（ID％／g）。（2）显像：①小鼠2只，注射^11C—AC后0．5min及20min显像；②正常女性志愿者3例，注射^11C—AC后2例行上腹局部早期即刻及全身延迟显像，1例行全身延迟显像和脑显像。结果1．改进前共合成^11C-AC113次，其中61次产量〈370MBq；改进后17次，产量全部〉370MBq。薄层层析法Rr=0．7～0．8，放射化学纯度〉90％。2．改进后产品：（1）小鼠体内分布：心、肾内放射l生随时间变化最大，胰腺、骨、肝和脾有中度摄取，膀胱、脑放射眭最低。（2）显像：（1）小鼠0．5min时心脏显影，20min时肝、脾显影清晰。②正常人早期心、肾及胰腺显影最清晰；延迟期心脏清除最快，肾实质内仍有少量放射性，胰腺内持续高摄取。肝、脾为中度摄取及清除，膀胱和脑内无放射性。结论美国CTI公司提供的^11C—AC自动合成模块经改进反应条件后，产量及放射化学纯度可以满足临床要求。Objective To improve the stability of ^11C-AC yields with CTI Inc, USA automatic synthesis module and to evaluate the product with biodistribution and imaging studies. Methods 1. Synthesis of ^11C-AC. The amount of quenching water was fixed to 0.2 ml instead of fluctuating from 0.1 to 0.2 ml. The purifying and distilling temperature were raised to 140 ℃-145℃ instead of 135 ℃. Thin layer chromatography was performed on products for quality control. 2. Biodistribution studies. （1） Twenty female mice were divided into 4 groups. Each mouse was killed separately 0.5 min, 5 rain, 10 rain and 20 min after injection. Blood and organs were weighed and their radioactivity measured （calculated to ID%/g） . （2） Two female mice were killed 0.5 min and 20 min separately after injection with ^11C-AC and imaged. （3） Three female volunteers underwent PET studies after injection. Initial upper abdomen scan for 2 cases, delayed whole body scan for 3 cases and brain scan for 1 case were performed. Results （1） Synthesis of ^11C-AC. A total of 113 syntheses were performed with original method. The yields of 61 syntheses were 〈370MBq （ less than one clinical dose）. After improvement, the yields of 17 syntheses were all 〉370 MBq （12 of them〉740 MBq）. The Rf of thin layer chromatograph was 0.7-0.8 and radiochemieal purity〉90%. （2） Biodistribution studies. The high uptake by heart and kidneys changed rapidly with time. Pancreas, liver and spleen had moderate uptake and clearance. （3） Imaging studies. In normal persons, heart, kidneys and pancreas showed high uptake in initial image and cleared rapidly from heart and kidneys, but the pancreas showed persistent high uptake in delayed image also. There was no radioactivity in bladder and brain. Conclusion The yield of ^11C-AC syntheses by our improved method is stable and fulfills the requirement for clinical uses.

关 键 词：^11C-乙酸盐 体层摄影术 发射型计算机 体内分布 

分 类 号：R[医药卫生]