44Sc production from enriched 47TiO2 targets with a medical cyclotron

• Published in: Applied radiation and isotopes 2024-04, Vol.206, p.111220-111220, Article 111220
• Main Authors: Dellepiane, Gaia, Casolaro, Pierluigi, Gottstein, Alexander, Mateu, Isidre, Scampoli, Paola, Braccini, Saverio
• Format: Article
• Language: English
• Subjects: Cross sections; Medical cyclotron; PET imaging; Proton irradiation; Scandium-44; Solid targets; Theranostics
• ISSN: 0969-8043; 1872-9800
• DOI: 10.1016/j.apradiso.2024.111220

44Sc is a β+-emitter which has been extensively studied for nuclear medicine applications. Its promising decay characteristics [t1/2 = 3.97 h, Eβ+ = 632 keV (94.3%), Eγ = 1157 keV (99.9%); 1499 keV (0.91%)] make it highly attractive for clinical PET imaging, offering an alternative to the widely used 68Ga [t1/2 = 67.7 min, Eβ+ = 836 keV (87.7%)]. Notably, its nearly fourfold longer half-life opens avenues for applications with biomolecules having extended biological half-lives and enables the centralized distribution of 44Sc radiopharmaceuticals. An additional advantage of employing 44Sc as a diagnostic radioisotope lies in its counterpart, the β−-emitter 47Sc, which is currently under investigation for targeted radiotherapy. Together, they form an ideal theranostic pair, providing a comprehensive solution for both diagnostic imaging and therapeutic applications in nuclear medicine. At the Bern medical cyclotron, a study to optimize the production of scandium radioisotopes is currently ongoing. In this context, proton irradiation of titanium targets has been investigated, exploiting the reactions 47Ti(p,α)44Sc and 50Ti(p,α)47Sc. This approach enables the production of Sc radioisotopes within a single PET medical cyclotron facility, employing identical chemical procedures for target preparation and post-irradiation processing. In this paper, we report on cross-section measurements of the 47Ti(p,α)44Sc nuclear reaction using 95.7% enriched 47TiO2 targets. On the basis of the obtained results, the production yield and purity were calculated to assess the optimal irradiation conditions. Production tests were performed to confirm these findings. •Measurement of the 47Ti(p,α)44Sc nuclear cross sections by irradiating 47Ti targets.•Measurements performed using an 18 MeV medical cyclotron and a beam transfer line.•Study of the thick target production yield and purity.•Production tests performed using a custom target station.•Suitable alternative route to produce 44Sc with a PET medical cyclotron.