Discoveries in fundamental science do not cease to contribute to the progress of humankind, namely in the field of health and medicine. A notable example is nuclear medicine that has seen important advances with the development of Targeted Alpha Therapy (TAT), which can provide highly targeted treatment to microscopic cancerous cells, and Theranostics, a new and promising practice that uses radiopharmaceuticals to both diagnose and treat various forms of cancer.
The use of radionuclides and alpha particles in medicine dates back to their discovery by Marie Curie, more than a hundred years ago, but their success at the clinical phase was only recently made possible by mastering their safe handling. Recent improvements in isotope production and purification, together with the adoption of innovative strategies for optimised targeting, have enabled the use of new drugs with appropriate physical properties. One of them is known as Actinium-225 (225Ac) - a promising yet scarce alpha emitter, whose decay properties are favourable in TAT, thanks to its half-life of 9.92 days and a net emission of 4 α particles in the decay chain, which allows a localised treatment of otherwise resistant tumour lesions and metastasis. Already produced at large-scale on the North American continent, this isotope is produced for medical usage for the first time in an accelerator in Europe, here at CERN.
Like other collaborations at CERN, the MEDICIS facility is building on particle accelerator knowledge to democratise nuclear medicine. Since its commissioning in 2017, the facility produces non-conventional, high-purity-grade radioisotopes for medicine, such as the Terbium isotope family, used for cancer diagnosis and treatment. On 28 June, MEDICIS received first protons on target from ISOLDE and produced first isotopes to prepare the physical separation and delivery of 225Ac to MEDICIS collaborating institutes. "With the strong need for 225Ac supply, which is today being delivered to medical research labs at the Catholic University of Leuven and in Islamabad," says MEDICIS leader, Thierry Stora, "we expect to attract new research groups in hospitals, thanks to the newly starting PRISMAP - The European Medical Radionuclides Programme." Currently, the majority of these isotopes are used in the form of 225Ac-labelled radiopharmaceuticals, both for preclinical developments as well as for clinical studies, focusing on the treatment of leukemia, prostate cancer, neuroendocrine tumours and gliomas.
Specialised in mass separation for purifying medical isotopes, the MEDICIS facility can obtain 225Ac by extracting it from an irradiated Thorium target and by removing 227Ac impurities.
Over 1000 isotopes from more than 70 chemical elements can be obtained at MEDICIS. Other radionuclides that will be produced through PRISMAP include Terbium-152, 213Bi-substance (which can also be derived from Actinium), and beta emitters such as Erbium-169, which will extend the scope of radiopharmaceutical research in Theranostics.
