{"entity":{"id":"sc-44","kind":"isotope","name":"Scandium-44","aka":["44Sc"],"tldr":"An experimental radioactive metal, lasting about four hours, being developed as a PET-imageable stand-in for lutetium-177 or other therapy metals so a treatment dose can be planned in advance.","summary":"Scandium-44 decays with a 3.97-hour half-life and an unusually high positron branching ratio of about 94%, giving PET image quality that compares favourably with gallium-68 while lasting roughly three times as long, long enough for regional distribution from a centralised production site rather than only local cyclotron use. Its chemistry closely resembles that of lutetium-177 and other trivalent lanthanide-like therapy metals, so DOTA-chelated scandium-44 tracers have been explored as a pre-therapy dosimetry match for 177Lu-labelled radioligands such as PSMA-617, an alternative to using 68Ga for the diagnostic scan when a metal-matched surrogate is preferred.\n\nIt is produced on a medical cyclotron via 44Ca(p,n)44Sc on an enriched calcium-44 target (natural abundance only about 2%, so enrichment adds cost), or via a 44Ti/44Sc generator in which the long-lived (60.4-year) parent titanium-44 supplies scandium-44 on an ongoing basis without a cyclotron, analogous to a 68Ge/68Ga generator.\n\nScandium-44 is also discussed as the diagnostic half of a prospective 44Sc/47Sc theranostic pair, since 44Sc and the beta-emitting therapy isotope scandium-47 are chemically identical, but as of the mid-2020s this pairing remains in early clinical and preclinical research rather than routine practice, and 47Sc production has not yet reached clinical scale.","status":"preclinical","asOf":"2026-09-22","links":[{"label":"PMC: production of scandium radionuclides for theranostic applications","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC8149571/"},{"label":"PMC: current state of 44Ti/44Sc radionuclide generator systems","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC10375575/"}],"tags":["positron emitter","generator","experimental theranostic pair"],"related":[],"indications":[],"sections":[],"technologies":["pet","cyclotron-isotope-production","radioligand-dosimetry"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"symbol":"44Sc","element":"Scandium","massNumber":44,"halfLife":"3.97 hours","emissions":["β+ 94.3% (mean 632 keV)","γ 1157 keV (99.9%)"],"emissionClass":"positron","use":"imaging","production":"Cyclotron: 44Ca(p,n)44Sc on enriched calcium-44 target; alternatively a 44Ti/44Sc generator (44Ti half-life ~60 years).","supply":"research-only","supplyNote":"Produced at a small number of research cyclotron and generator sites; enriched calcium-44 targets and 44Ti generator stock are both limited, and no scandium radiopharmaceutical has reached routine clinical supply as of the mid-2020s.","chelators":["DOTA"],"pairedWith":[],"since":2013},"route":"/isotopes/sc-44/","neighbours":{"technology":[{"id":"cyclotron-isotope-production","kind":"technology","name":"Cyclotron isotope production (F-18, Ga-68, Cu-64, Zr-89, At-211)","route":"/technologies/cyclotron-isotope-production/"},{"id":"pet","kind":"technology","name":"PET (positron emission tomography)","route":"/technologies/pet/"},{"id":"radioligand-dosimetry","kind":"technology","name":"Radioligand dosimetry","route":"/technologies/radioligand-dosimetry/"}],"idea":[{"id":"idea-total-body-pet-dosimetry","kind":"idea","name":"Total-body PET for personalised radioligand dosing","route":"/ideas/idea-total-body-pet-dosimetry/"}],"term":[{"id":"chelator-term","kind":"term","name":"Chelator (bifunctional chelating agent)","route":"/terms/chelator-term/"},{"id":"theranostic-pair-term","kind":"term","name":"Theranostic pair","route":"/terms/theranostic-pair-term/"}]}}