Production of Cyclotron-Based Gallium-68 With Low Energy Protons: Preliminary Target Design and Cyclotron Shielding Considerations

Nuclear reactors, cyclotrons and generators are being used to produce nuclear medicine radionuclides. Radiopharmaceuticals based on Gallium-68 are widely used both experimentally and clinically in Positron Emission Tomography (PET). Currently Ga-68 is mainly produced via 68Ge/68Ga generators, which are expensive. An alternative method is by cyclotron using high enriched Zinc-68 via the 68Zn(p,n)68Ga reaction. Investigations have been conducted for producing Ga-68 using a solid target impacted with a proton beam in energies between (13–14) MeV or higher. The main interest of this work is to produce Ga-68 using energies within a lower range, therefore Ga-68 can be accessed to locations with cyclotrons of lower energy. In this article, an approach to a novel target design to get Ga-68 with low energy protons is conducted. Adequate shielding to avoid extra doses outer the cyclotron is also considered. Monte Carlo code FLUKA is used to simulate the processes of interaction of radiation with matter and the radioactive isotope production. For a beam energy of 11 MeV and current on target of 40 μA the simulated produced activity is about 69.1 GBq. The results show the feasibility of producing Ga-68 with low energy protons and self-shielding system guarantees the regulation-based dose exposition outer the cyclotron.