Theoretical assessment and optimization of cyclotron production routes for high-purity ^110mIn for PET applications.

Abstract

The positron-emitting radionuclide indium-110 (110mIn; T½ = 69.1 min, Jπ = 2+, Ex = 0.0621 MeV) is an attractive candidate for the positron emission tomography (PET). In the present work, the cyclotron production routes of 110mIn through proton induced reactions on cadmium isotopes (i.e.¹¹⁰Cd, ¹¹¹Cd, ¹¹²Cd, natCd) along with the ¹⁰⁷Ag(α,n) process are investigated for the direct production of 110mIn and 110gIn. The measured excitation functions are compared with the prediction by the nuclear model codes, TALYS, EMPIRE and ALICE-IPPE. The isomeric cross sections ratios are envisaged to compare the isomeric and ground states over the discussed energy range. The integral yields are deduced for 110mIn, 110gIn and ¹⁰⁹In. The optimum energy ranges, to produce the desired 110mIn, are presented along with the co-production 110gIn and ¹⁰⁹In levels. The results demonstrate that the ¹¹⁰Cd(p,n) reaction provides the most favorable compromise between yield and purity for the cyclotron production of 110mIn. The evaluated excitation functions and recommended energy ranges provide useful guidance for the practical production of 110mIn for PET applications. The study identifies optimum projectile energy windows for maximizing the production of 110mIn while minimizing radionuclidic impurities.