Technology Verification for Automated Synthesis Process of ¹⁸F-FMISO Based on Domestic Fluorine Multifunctional Module

1-H-1-(3-¹⁸Ffluoro-2-hydroxypropyl)-2-nitroimidazole(¹⁸F-FMISO) is a special tumor hypoxia imaging agent for PET. Its PET/CT imaging has an important guiding significance on planning cancer radiotherapy target volume. ¹⁸F-FMISO was synthesized on domestic fluorine multifunctional automated synthesis apparatus. By using 1-(2′-nitro-1′-imidazolyl)-2-O-tetrahydropyranyl-3-O-toluenesulphonyl-propanediol as the precursor, ¹⁸F-FMISO was obtained via two-step reactions, including the nucleophilic fluoration of the precursor and the acidic hydrolysis of the intermediate. To verify the feasibility, reliability and stability of the automated synthesis process, three continuous batches of ¹⁸F-FMISO were produced with optimized preparation process. The key parameters in the pilot production and the quality standard of the product were verified. The procedure could be completed within 40 minutes. The radiochemical yield and specific activity were higher than 45% (no decay corrected, n=5) and 3.7×10¹⁰ Bq/mmol. The radiochemical purity was more than 95% after three half-life, indicating its good stability. The automated synthesis process of ¹⁸F-FMISO is feasible. All the indicators for each batch of ¹⁸F-FMISO meet the quality standard and the requirements of clinical PET imaging.