Comparison of the impact of two versions of reagent and ancillary sets on the [18F]FDG radiochemical yield

Aim: The purpose of this study is to compare the impact of the optimised versus standard version of the reagent set and ancillary kit on the [18F]FDG radiochemical yield. Materials and Methods: [18F]Fradioisotope is produced in a cyclotron (GE PETtrace 16.5 MeV) by irradiating enriched 18O water with protons. [ 18F]FDG radiosynthesis (a nucleophilic 18F-fluorination followed by base-catalyzed hydrolysis) is conducted using an automated synthesizer IBA Synthera V2 module and a single-use disposable system – Integrated Fluid Processor (IFP) as well as reagents and ancillary set. There are two commercially available versions of these sets. In the new version of the reagents set, the molar ratio acetonitrile-water in the cryptand solution is 4:1 instead of 1:1. As the separation cartridge in the new version of the ancillary kit is used QMA Carbonate Plus Light, instead of QMA Plus Light. A modification is also made in the purification cartridges, Oasis HLB in place of the C18 cartridge. In this study, 100 [18F]FDG batches in total are analyzed. 50 batches were synthesized using the standard version of the reagent and ancillary kits, while the other 50 batches were with the optimised version. The mean radiochemical yield (RCY), decay-corrected, and relevant standard deviation (SD) are calculated for both types of analyzed batches. Results: [18F]FDG batches produced using the optimised version of reagents and ancillary kit has higher RCY (65.01% ± 4.52%) compared to the batches produced using the standard version (57.83% ± 3.61%). Conclusion: This study confirms that the optimisation of the reagent and ancillary sets contributes to a higher radiochemical yield of the produced [ 18F]FDG

2-[18F]fluoro-2-deoxy-D-glucose production: correlation between yield and eob activity

2-[18F]fluoro-2-deoxy-D-glucose ([18F]FDG) production is a routine synthesis process, involving fully automated synthesizer with single-use disposable system - integrated fluidic processor (IFP cassette) and overall synthesis time of 30 minutes. The synthesis of [18F]FDG is a six-step process consisting of two chemical reactions, a nucleophilic 18F- fluorination followed by a base-catalyzed hydrolysis. 18F- is produced by irradiating enriched [18O]-water with protons with GE PETtrace 16.5 MeV cyclotron, at University Institute of Positron Emission Tomography, Skopje. The amount of starting radioactivity depends on the desired radioactivity of final product, so because of that, our objective was to determine whether amount of starting radioactivity affects the radiolabeling efficiency and the capacity of starting materials or the production yield. Forty batches of [18F]FDG were produced with same IFP cassette and the same reagent kit (different batch production but same producer). The mean decay corrected production yield for [18F]FDG produced by starting radioactivity of 18F- from 20-35 GBq, 55-75 GBq and 150-170 GBq were 71,44% ± 5,5%, 70,13% ± 5,5% and 67,11% ± 2.3%, respectively. The results confirm that the starting radioactivity of radioisotope does not affect the production yield and there is no significant difference between the results in these three groups of results, p>0.05 (0.069). [18F]FDG was successfully synthesized with a production yield above 60% in all batches, as result of the high-quality and the large capacity of starting materials for radioactivity to give efficient radiochemical synthesis