OPTIMIZATION OF THE PRODUCTION OF TERBIUM RADIONUCLIDES FOR THERANOSTIC APPLICATIONS

The field of nuclear medicine has significantly advanced since the discovery of artificial radioactivity in 1934. Among the developments, theranostics has emerged as a promising approach combining diagnostics and therapy using radiopharmaceuticals labeled with chemically identical radionuclide pairs. In particular, the terbium isotopes 149Tb, 152Tb, 155Tb, and 161Tb have shown great potential due to their unique decay properties, enabling precise imaging and effective treatment modalities. This thesis focuses on the optimization of terbium radioisotopes production using charged-particle-induced nuclear reactions. Due to the scarcity of experimental data and discrepancies in the literature, cross-sections for five nuclear reactions involving terbium, gadolinium, europium, and dysprosium targets were measured using cyclotron facilities at GIP ARRONAX (France) and LASA (Italy). The study addresses several challenges in radionuclide production, including yield maximization, radionuclidic purity, and specific activity, which are crucial for theranostic applications. The results demonstrate optimal production routes for 155Tb through the indirect 159Tb(p,x)155Dy reaction, achieving a high yield of 1.2 GBq/µA and radionuclidic purity above 99.9 %. Similarly, potential production methods for 152Tb and 155Tb via natural and enriched europium targets were evaluated. However, the direct production of 149Tb remains challenging due to low yields and complex separation processes. In addition, a radiochemical separation protocol using extraction chromatography was developed for purifying terbium from gadolinium and dysprosium contaminants. The findings highlight key production pathways and offer valuable insights for future clinical applications of terbium radionuclides in theranostics, potentially overcoming existing production limitations and expanding their use in personalized cancer treatment.