Optimization of the production of the theranostic 155Tb using alpha-induced reactions on natGd targets

The present work focuses on 155Tb, a promising terbium radioisotope whose decay characteristics are well suited to theranostics, a nuclear medicine technique of growing interest that combines diagnosis and therapy. One of the main objectives is the study of the production cross-section of 155Tb (T_1/2 = 5.32 d) starting from the nuclear reaction natGd(α,x). The irradiations were carried out at the GIP Arronax cyclotron in Saint-Herblain (France) with α-particle beams in the energy range (20–45) MeV using the stacked foils activation technique while the gamma spectrometry measurements were performed both at the GIP Arronax and at the LASA laboratories (University of Milan and INFN-MI, Segrate, Italy). Furthermore, an indirect production method is proposed through the formation of the parent radionuclide 155Dy (T_1/2 = 9.9 h). All the results obtained were compared with experimental data in the literature and with the nuclear simulation code TALYS 1.96.