A robotic synthesis of [18F]fluoromisonidazole ([18F]FMISO)

This study aimed to develop an automated synthesis of [18F]fluoromisonidazole ([18F]FMISO) using a Scanditronix Anatech RB III robotic system. [18F]HF was produced via the 18O(p,n)18F reaction using a Scanditronix MC17F cyclotron. On average, a typical run produced [18F]FMISO with an uncorrected radiochemical yield of 30±5% at end of synthesis (EOS) from the irradiation of 95% enriched [18O]water. The total synthesis time was 65 min. The retention time of [18F]FMISO (the radio-peak) was 4.9 min, which was consistent with the authentic FMISO (the ultraviolet peak). The radiochemical purity was greater than 97%. Preparation of [18F]FMISO using the automated robotic system is highly reliable and reproducible, and the radiation burden for the operator can be largely reduced. Sufficient radioactivities of [18F]FMISO could be obtained for non-invasive tumor hypoxia imaging in vivo with positron emission tomography (PET).