Abstract:

Objective: To verify the efficiency and stability of the automated labeling and synthesis of dopamine transporters (DAT) imaging probe, ¹⁸F-N-(3-fluoropropyl)-2β-carbomethoxy-3β-(4′-iodophenyl) nortropane (¹⁸F-FP-CIT), based on the AllinOne module. Meanwhile, to evaluate the safety and targeted ability of the probe and the imaging effect on the basal ganglia of rats. Methods: A fluorination reaction between nitrogen-[3-(methoxy)propyl]-2β-carbonmethoxy-3β-(4′-iodophenyl) nortropane, the reaction precursor, and the dried fluorine-18 ion (¹⁸F) was performed, under the catalysis of TBAOH and Kryptofix 222. The product of the reaction was separated and purified by high performance liquid chromatography (HPLC). All the procedure was established on the AllinOne module under the highest yield conditions to perform automated labeling and synthesis of ¹⁸F-FP-CIT. Quality control tests and Micro PET/CT imaging of rat brain with the automatically synthesized product were carried out. Results: The average synthesis time, efficiency after attenuation correction, and radiochemical purity of 20 batches of ¹⁸F-FP-CIT made by the AllinOne module was (72.9±8.9) min, 34.8%±5.7%, and 98.4%±2.0%, retrospectively. The results of sterility test, endotoxin test, toxicity test and residual solvent test of acetonitrile were all met the clinical practice standards. Micro PET/CT imaging showed uniform and obvious targeted uptake of ¹⁸F-FP-CIT in basal ganglia of normal rats, and the uptake of ¹⁸F-FP-CIT in basal ganglia was 2.6 times that in cerebral cortex, 3.7 times that in cerebellum, and 4.1 times that in skull, respectively. Conclusions: The AllinOne module can automatically label and synthesize DAT imaging probe ¹⁸F-FP-CIT stably, rapidly, with high-quality, which is expected to provide imaging technical support for the clinical diagnosis and treatment of neurodegenerative changes such as Parkinson′s disease (PD).

Key words: Dopamine transporter, ¹⁸F-N-(3-fluoropropyl)-2β-methylester-3β-(4'-iodophenyl) nortropane, Trasis AllinOne Module, Automated synthesis, Micro PET/CT imaging