Accelerator produced 99mTc for medical applications: Technical and chemical optimizations

Alternative production methods for molybdenum-99 ( 99 Mo), the parent nuclide of technetium-99 m ( 99m Tc), have gained significant attention over the past two decades, particularly in response to vulnerabilities in the current reactor-based supply chain. A major challenge in implementing accelerator-driven production routes is the lower specific activity of 99 Mo obtained compared to that produced via fission of highly-enriched uranium-235 ( 235 U). In the present work, we report experimental investigations supporting the development of a low specific activity (LSA) 99 Mo/ 99m Tc generator system based on the ‘High Brilliance Neutron Source’ (HBS) accelerator under development at Forschungszentrum Jülich. To address limitations associated with LSA 99 Mo, we explored several parameters, including the use of γ-Al 2 O 3 as alternative column material with higher Mo adsorption capacity and enhanced 99 Mo loading via higher concentrated Mo solutions obtained from dissolving thicker targets to optimize the generator system. Elution efficiency and 99 Mo breakthrough were evaluated in a modified mock-up generator system, showing promising results within regulatory thresholds for clinical application. These findings demonstrate the feasibility of using LSA 99 Mo in clinically compatible generators with minimal system redesign. Future work will focus on refining the irradiation and chemical processing protocols and evaluating implementation into clinical practice.