Theranostics is a powerful technique that combines diagnostic 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, which is being measured with high precision. Beyond Scandium, other radioisotopes are investigated (Ga-68, Cu-61, Cu-64, Tb-155, V-48, Er-165, Tm-165).
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). It foresees two delivery pathways: to the hot-cell in the radio-pharmacy and to the BTL research bunker.
To load the solid target station without opening and accessing the cyclotron bunker, we developed a mechanical automatic system named HyperLoop. This device allows to drastically reduce both the waiting time and the radiation exposure of the personnel.
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