Theranostic agents in nuclear medicine allow for strategies that combine diagnosis and therapy for optimized patient care. Imaging with chemically identical diagnostic and therapeutic agents is ideal as the chemical structure of the compound remains the same. Therefore, the development of matched radionuclide pairs for use in receptor targeted therapies and imaging is an emerging area of research. One promising radionuclide pair is the positron-emitting ⁴³Sc (t_1/2= 3.90 h) and beta-emitting⁴⁷Sc (t_1/2= 3.35 d). In particular, production routes for ⁴⁷Sc are underexplored.
Work was carried out to investigate yield, targetry, and purification chemistry to determine the feasibility of producing ^43,47Sc using enriched titanium targets via the ⁴⁶Ti(p,a)⁴³Sc and ⁵⁰Ti(p,a)⁴⁷Sc reactions, Scandium-47 was produced by the⁵⁰Ti(p,α)⁴⁷Sc reaction, using pressed powder enriched titanium oxide targets prepared in house. Targets were contained in a coin style target holder and irradiated on a TR-24 cyclotron at the University of Alabama at Birmingham. Irradiated targets were digested with NH₄HF₂and then dissolved in heated HCl. After digestion, ⁴⁷Sc was isolated and purified by cation exchange chromatography using branched DGA resin with a mean recovery of 90 ± 3%. Recovery of the enriched titanium target material was >95%. ⁴⁷Sc was used to synthesize [⁴⁷Sc]PSMA-617 to illustrate the utility of the produced radioisotope. Data from these experiments show that ⁴³Sc/⁴⁷Sc can be produced, separated, and purified from enriched Ti targets. These results support further investigation of ⁴³Sc/⁴⁷Sc production and radiochemisty studies.

Jose Blanco

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