AUTHOR=Becker Kaelyn V. , Aluicio-Sarduy Eduardo , Bradshaw Tyler , Hurley Samuel A. , Olson Aeli P. , Barrett Kendall E. , Batterton Jeanine , Ellison Paul A. , Barnhart Todd E. , Pirasteh Ali , Engle Jonathan W. TITLE=Cyclotron production of 43Sc and 44gSc from enriched 42CaO, 43CaO, and 44CaO targets JOURNAL=Frontiers in Chemistry VOLUME=11 YEAR=2023 URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2023.1167783 DOI=10.3389/fchem.2023.1167783 ISSN=2296-2646 ABSTRACT=

Introduction:⁴³Sc and ^44gSc are both positron-emitting radioisotopes of scandium with suitable half-lives and favorable positron energies for clinical positron emission tomography (PET) imaging. Irradiation of isotopically enriched calcium targets has higher cross sections compared to titanium targets and higher radionuclidic purity and cross sections than natural calcium targets for reaction routes possible on small cyclotrons capable of accelerating protons and deuterons.

Methods: In this work, we investigate the following production routes via proton and deuteron bombardment on CaCO₃ and CaO target materials: ⁴²Ca(d,n)⁴³Sc, ⁴³Ca(p,n)⁴³Sc, ⁴³Ca(d,n)^44gSc, ⁴⁴Ca(p,n)^44gSc, and ⁴⁴Ca(p,2n)⁴³Sc. Radiochemical isolation of the produced radioscandium was performed with extraction chromatography using branched DGA resin and apparent molar activity was measured with the chelator DOTA. The imaging performance of ⁴³Sc and ^44gSc was compared with ¹⁸F, ⁶⁸Ga, and ⁶⁴Cu on two clinical PET/CT scanners.

Discussion: The results of this work demonstrate that proton and deuteron bombardment of isotopically enriched CaO targets produce high yield and high radionuclidic purity ⁴³Sc and ^44gSc. Laboratory capabilities, circumstances, and budgets are likely to dictate which reaction route and radioisotope of scandium is chosen.