Preparation of 68Ga-PSMA-617 and its microPET imaging in BGC-823 cell bearing mice / 中华核医学与分子影像杂志

ABSTRACT

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 68GaCl3 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 HAS 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 microPET 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％ HAS,the radiochemical 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.