中文摘要：

目的制备68Ga-PSMA-617探针，并进行放射性药物质量控制。用microPET研究该探针在正常鼠和PSMA（＋）的荷人胃癌肿瘤（BGC-823）裸鼠体内的代谢情况。方法以0.05 mol/L HCl淋洗^68Ge-68Ga发生器得到68GaCl3，与DKFZ-PSMA-617试剂盒于85 ℃下反应5 min。用HPLC分析68Ga-PSMA-617的标记率以及在生理盐水和HSA体系中的稳定性，并测定脂水分配系数和蛋白结合率，对正常雌性BALB/c小鼠和BGC-823荷瘤鼠进行68Ga-PSMA-617 microPET显像，并与18F-FDG microPET显像进行对比。结果68Ga-PSMA-617的标记率达97.9%，可不经纯化直接使用。标记物在生理盐水和质量分数5%的HSA体系中稳定性良好，放置80 min后放化纯分别为94.9%和81.0%。小鼠体内分布结果表明，标记物主要经肾脏代谢，BGC-823荷裸鼠肿瘤部位有较高的放射性摄取（T/NT为2.28），且显像效果优于18F-FDG。结论68Ga-PSMA-617的制备简便且标记率高，可靶向PSMA（＋）肿瘤部位，显像效果优于18F-FDG，有望应用于PSMA高表达肿瘤的临床诊断。

英文摘要：

Objective To prepare 68Ga-PSMA-617 and perform its microPET imaging on both normal BALB/c mice and BGC-823 （PSMA expression） tumor bearing mice. Methods ^68 GaCl3 was eluted from ^68Ge-^68Ga generator by 0.05 mol/L HCl, then added to the DKFZ-PSMA-617 and heated at 85 ℃ for 5 min. The labeling efficiency and in vitro stability of ^68Ga-PSMA-617 in sodium chloride solution and HSA were analyzed by radio-HPLC. Water partition coefficient and plasma protein binding rate were also evaluated. MicroPET imaging was performed in normal female BALB/c mice and human gastric tumor （BGC-823） bearing mice at 60 min post-injection of ^68Ga-PSMA-617. ^18F-FDG was also injected to BGC-823 tumor bearing mice to acquire mieroPET imaging for contrast. Results The labeling yield of ^68Ga-PSMA-617 was 97.9%, and it could be used directly without purification. ^68Ga-PSMA-617 showed good in vitro stability in sodium chloride solution and 5% HSA, the radiochemieal purities were 94.9% and 81.0% respectively at 80 min post-incubation. 68Ga-PSMA-617 was water-solubility substance, and it cleared mainly through the kidneys. MicroPET imaging showed that ^68Ga-PSMA-617 could be accumulated in tumor （T/NT = 2. 28）, which was better than ^18F-FDG. Conclusions Preparation of ^68Ga-PSMA-617 is convenient and has a high labeling yield. It can specifically target to PSMA expression tumors and has a promising prospect in clinical application.