s Scandium-44: Benefits of a Long-Lived PET Radionuclide Available from the 44Ti/44Sc Generator System

44Ti/44Sc radionuclide generators are of interest for molecular imaging. The 3.97 hours half-life of 44Sc and its high positron branching of 94.27% may stimulate the application of 44Sc-labeled PET radiopharmaceuticals. This review describes the current status of 44Ti production, 44Ti/44Sc radionuclide generator development, post-processing of generator eluates towards medical application, identification of ligands adequate to ScIII co-ordination chemistry, proof-of-principle labeling of 44Sc-DOTA-octreotides, investigation of in vitro and in vivo parameters, and initial applications for molecular imaging – both in small animals and humans.