Imaging of hypoxia in small animals with ¹⁸F fluoromisonidasole

A method of automated synthesis of [¹⁸F]fluoromisonidazole ([¹⁸F]FMISO) for application in preclinical studies on small animals was presented. A remote-controlled synthesizer Synthra RN_plus was used for nucleophilic substitution of NITTP (1′-(2′-nitro-1-imidazolyl)-2-O-tetrahydropyranyl-3-O-toluenesulfonyl-propanediol) with ¹⁸F anion. Labeling of 5 mg of precursor was performed in anhydrous acetonitrile at 100°C for 10 min, and the hydrolysis with HCl was performed at 100°C for 5 min. Final purification was done with high-performance liquid chromatography (HPLC) and the radiochemical purity of radiotracer was higher than 99%. Proposed [¹⁸F]FMISO synthesis was used as a reliable tool in studies on hypoxia in Lewis lung carcinoma (LLC) in mouse models.