在线合成心肌灌注显像剂:碳-11三苯甲基磷

In-LOOP synthesis of ^(11)C-Triphenylmethylphosphonium for myocardial perfusion imaging

99mTc-MIBI是常用的心肌灌注显像剂,肝摄取高,临床应用有一定的影响。11C-三苯甲基磷(11C-TPMP)为脂溶性正一价阳离子,用于心肌显像能得到更好的分辨率。以11CH3-Triflate为甲基化试剂,采用LOOP法在线合成了11C-TPMP,研究了11C-TPMP在正常小鼠的分布,正常大鼠行Micro PET显像,并与4位18F-苯基三苯基磷(18F-FTPP)比较。结果显示,LOOP法合成11C-TPMP效率大于90%(校正),放化纯度大于98%。正常小鼠心肌有高的摄取,注射后5 min和60 min,心肌摄取分别为(71.9±19.9)%ID.g–1和(12.87±0.81)%ID.g–1,肝摄取低,注射后5 min和60 min心肝摄取比分别为11.57和3.2。正常大鼠micro PET显像显示,从20 min到60 min,心肌显像清晰,肝未显像。表明LOOP法可高效合成11C-TPMP,11C-TPMP是一个很有希望的心肌灌注显像剂。

Background： 99mTc-MIBI was used as myocardial perfusion SPECT. However, the high accumulation of tracers in the liver and lung may hinder the detection of flow abnormalities in myocardium. Purpose： vC-Triphenylmethylphosphonium （llC-TPMP） was a lipophilic cation, has been investigated as a positron emission tomography （PET） agent for myocardial and tumor imaging to provide a better temporal and spatial resolution than SPECT. Methods： IxC-TPMP was prepared by reacting [nc]methyl trifalte with In-LOOP method. Biodistribution studies in mouse were performed. And micro PET was performed with rat, and compared with 4-[18F]fluorophenyl triphenylphosphonium ion（18F-FTPP）. Results： The results showed that the IIC-TPMP labeling yield was over 90%, the radiochemical purity was over 98%. The biodistribution showed high accumulation of radioactivity in the heart （71.9~19.9）%ID＇g-1 at 5 rain and （12.87~0.81）%ID＇g-l at 60 min post injection. The heart/liver ratios were 11.57 and 3.2 at 5 rain, 60 min respectively. Micro PET scans showed distinct accumulation of llC-TPMP in the myocardium from 20 min to 60 min. The liver had very lower accumulation of radioactivity. Conclusions： 11C-TPMP was a promise PET perfusion agent for myocardial. It would be useful in clinical with In-LOOP synthesis.