An Unusual Pair: Facile Formation and In Vivo Validation of Robust Sc–18F Ternary Complexes for Molecular Imaging

Abstract Fluorine‐18 remains the most widely clinically utilized radionuclide globally for positron emission tomography (PET). The emergence of therapeutic isotopes for the management of disease has produced a pronounced interest in matched, theranostic isotope pairs that can be employed in tandem for the diagnosis and stratification of patients for subsequent radiotherapy. 18 F, however, does not have a suitable therapeutic isotopologue. Here, we demonstrate that the formation of [ 18 F][Sc−F] ternary complexes is feasible under mild, aqueous conditions, producing chemically robust radiopharmaceuticals in high radiochemical yield and specific activity. A corresponding in vivo study with a cancer‐targeting [ 18 F][Sc−F] tracer indicates excellent in vivo stability and produces exquisite PET image quality, rendering the 18 F/ 47 Sc isotope pair an unusual, yet chemically matched theranostic pair with excellent potential for clinical translation.