Theranostics is a powerful technique that combines diagnostics and therapy in medicine, for cancer treatments in particular. It combines one radioactive drug to identify (diagnose) and a second radioactive drug to deliver therapy to treat, for example, a tumour.
With the Bern cyclotron, we tackle the scientific and technological challenges of producing suitable quantities of high-purity Sc-43 and Sc-44, which, in combination with Sc-47, are appealing candidates for theranostics in nuclear medicine. Our group develops novel techniques based on solid targets. In particular, a specific target "coin" was conceived and realised to bombard material in form of powder compressed in 6-mm diameter pellets. Another aspect of this challenge is the measurement of the production cross-section with high precision. Other radioisotopes are being investigated in addition to scandium (Ga-68, Cu-61, Cu-64, Tb-155, V-48, Er-165, Tm-165). The group was awarded the IBA award 2020 for the publication on the production of Sc-44 with the Bern cyclotron (see "Selected publications" below). This work was performed in collaboration with the Paul Scherrer Institute (PSI).
The "coin" consists of two halves of high-purity aluminium kept together by permanent SmCo magnets. An O-ring is inserted to avoid radioactive degassing during the irradiation. The coin is filled with powder material compressed into a pellet (e.g. 6-mm diameter, 500-um thickness, ~30 mg CaO for Sc and ~100 mg Zn for Ga production). The coin is closed in an inert Ar atmosphere. The thickness of the front side of the coin can be varied to allow for different entry energies to optimise the purity and quantity of the produced radioisotopes. This is done on the basis of their cross sections.
The Bern cyclotron is equipped with an IBA NIRTA Solid Target Station with a pneumatic target transfer system by TEMA Sinergie (Italy), named STTS (Solid Target Transfer System). This system allows delivery of the irradiated target to a shielded canister in the BTL bunker, from where it can be shipped to neighbouring radiochemistry and radiopharmacy facilities.
To load the solid target station without opening and accessing the cyclotron bunker, we developed a mechanical automatic system named Hyperloop. This device drastically reduces both the waiting time and the radiation exposure of the personnel.
G. Dellepiane, P. Casolaro, A. Gottstein, I. Mateu, P. Scampoli and S. Braccini, Study of 67Cu optimized production based on cross section measurements of 67Cu and 64Cu using an 18 MeV medical cyclotron, Applied Radiation and Isotopes 195 (2023); 110737; https://doi.org/10.1016/j.apradiso.2023.110737
G. Dellepiane, P. Casolaro, I. Mateu, P. Scampoli and S. Braccini, Alternative routes for 64Cu production using an 18 MeV medical cyclotron in view of theranostic applications, Applied Radiation and Isotopes, 191 (2023); 110518; https://doi.org/10.1016/j.apradiso.2022.110518
G. Dellepiane, P. Casolaro, I. Mateu, P. Scampoli, N. Voeten and S. Braccini, Cross section measurements for an optimized 61Cu production at an 18 MeV medical cyclotron from natural Zn and enriched 64Zn solid targets, Applied Radiation and Isotopes, 190 (2022); 110466; https://doi.org/10.1016/j.apradiso.2022.110466
G. Dellepiane, P. Casolaro, C. Favaretto, P. V. Grundler, I. Mateu, P. Scampoli, Z. Talip, N. P. van der Meulen, S. Braccini, Cross section measurement of Terbium radioisotopes for an optimized 155Tb production with an 18 MeV medical PET cyclotron, Applied Radiation and Isotopes, Volume 184, June 2022, 110175, https://www.sciencedirect.com/science/article/pii/S0969804322000744
S. Braccini, T. S. Carzaniga, G. Dellepiane, P. V. Grundler, P. Scampoli, N. P. van der Meulen, D. Wüthrich, Optimization of 68Ga production at an 18 MeV medical cyclotron with solid targets by means of cross-section measurement of 66Ga, 67Ga and 68Ga, Applied Radiation and Isotopes, Volume 186, August 2022, 110252, https://www.sciencedirect.com/science/article/pii/S0969804322001488
N. P. van der Muelen, R. Hasler, Z. Talip, P. V. Grundler, C. Favaretto, C. A. Umbricht, C. Müller, G. Dellepiane, T. S. Carzaniga, S. Braccini, Developments toward the Implementation of Sc-44 Production at a Medical Cyclotron, Molecules 2020, 25(20), 4706; https://doi.org/10.3390/molecules25204706
S. Braccini, C. Belver-Aguilar, T.S. Carzaniga, G. Dellepiane, P.D. Häffner, P. Scampoli, Novel Irradiation Methods for Theranostic Radioisotope Production with Solid Targets at the Bern Medical Cyclotron, Proceedings of the International Conference on Cyclotrons and their Applications (CYC), Cape Town, South Africa, 22–27 September 2019; https://doi.org/10.18429/JACoW-Cyclotrons2019-TUA02