Fully automated synthesis of 11C-acetate as tumor PET tracer by simple modified solid-phase extraction purification

Abstract

IntroductionAutomated synthesis of 11C-acetate (11C-AC) as the most commonly used radioactive fatty acid tracer is performed by a simple, rapid, and modified solid-phase extraction (SPE) purification. MethodsAutomated synthesis of 11C-AC was implemented by carboxylation reaction of MeMgBr on a polyethylene Teflon loop ring with 11C-CO2, followed by acidic hydrolysis with acid and SCX cartridge, and purification on SCX, AG11A8 and C18 SPE cartridges using a commercially available 11C-tracer synthesizer. Quality control test and animals positron emission tomography (PET) imaging were also carried out. ResultsA high and reproducible decay-uncorrected radiochemical yield of (41.0±4.6)% (n=10) was obtained from 11C-CO2 within the whole synthesis time about 8min. The radiochemical purity of 11C-AC was over 95% by high-performance liquid chromatography (HPLC) analysis. Quality control test and PET imaging showed that 11C-AC injection produced by the simple SPE procedure was safe and efficient, and was in agreement with the current Chinese radiopharmaceutical quality control guidelines. ConclusionThe novel, simple, and rapid method is readily adapted to the fully automated synthesis of 11C-AC on several existing commercial synthesis module. The method can be used routinely to produce 11C-AC for preclinical and clinical studies with PET imaging.