The copper trilogy: exploring 61Cu, 64Cu and 67Cu at the Bern medical cyclotron

Abstract The clinical implementation of copper-based theranostics requires reliable production strategies compatible with routine hospital-based operation. In this work, the feasibility of producing 61 Cu, 64 Cu, and 67 Cu within a single 18 MeV medical cyclotron facility equipped with a solid target station was systematically investigated using proton irradiation of natural and enriched zinc targets. Based on experimentally determined excitation functions, production yields and radionuclidic purities were calculated under realistic irradiation scenarios to identify optimized operating conditions for each radionuclide. Dedicated production tests were performed to validate these findings. The results demonstrate the feasibility of integrated multi-isotope copper production within a single medical cyclotron infrastructure, supporting the clinical translation of copper-based theranostic systems.