The production of novel medical radioisotopes by the ISOL technique: on the example of CERN MEDICIS

Invited contributionThe production of medical radioisotopes is largely dominated by neutron capture at nuclear reactors and fusion-evaporation reactions with cyclotrons based at medical facilities. While those techniques are quite efficient, only a handful of different radioisotopes are regularly used by the medical community. This is in part due to the difficult access to novel radioisotopes during the long pre-clinical and clinical studies. In contrast to this picture, the ISOL technique is rather inefficient for a given radioisotope, but it provides access to a wide catalog of radioisotopes for research. This motivated the construction of the CERN MEDICIS facility (MEDical Isotopes Collected from ISolde), where targets can be irradiated parasitically to the operation of CERN ISOLDE, and where radioisotopes can be extracted from those targets at an offline separator, based on the know-how developed by the ISOL community since 50 years. This project is driven in partnership with medical research institutions which have identified the most promising candidates for personalised healthcare: the use of theranostic sets of isotopes and alpha radiotherapy. Theranostic radioisotopes are a set of isotopes which combine different properties in terms of functional imaging and radiotherapy, while maintaining the same chemical properties: e.g. 149Tb (alpha for therapy), 152Tb (beta+ for PET), 155Tb (gamma for SPECT), and 161Tb (beta- for therapy). For alpha therapy, one of the most promising isotope is 213Bi, which short half-life makes it better suited as produced from a 225Ac generator (half-life 15 days). The key isotopes described above (namely 149Tb and 225Ac) are not readily available from existing facilities, and their production might be limited to the ISOL technique. As a community, we must therefore assess whether our projects can incorporate large-scale production of medical radioisotopes to complement the fundamental research in a way that is sustainable for treatments in Europe and beyond. In this presentation, I shall present the status of CERN MEDICIS and the context around which the research is based. I shall then briefly open the discussion towards how EURISOL DF and later EURISOL might need to include this component in its design and operation.status: publishe