Introduction:
The nuclide 225 Ac and its decay product 213 Bi have been identified as very suitable for targeted alpha-immuno-therapy [1]. First treatments of patients with acute myelogenous leukemia with a 213 Bi-labelled antibody HuM195 at Sloan Kettering Memorial Cancer Center, New York, proved very encouraging [2]. A draw back and bottleneck for extended clinical trials is the worldwide very limited availability of 225 Ac, which currently is separated in intervals of about 9 weeks from a stock of 229 Th [3]. Alternatively, 225 Ac can be produced in the reaction 226 Ra(p,2n) at a cyclotron. Due to the difficulties involved handling larger quantities of 226 Ra and separating clinical grade 225 Ac from the irradiated targets, no routine production of 225 Ac has been accomplished so far.
Experimental: At Technical University of Munich an old, but still operational 22 MeV H + cyclotron (AEG) was available to start up routine production of 225 Ac. As a goal the production of 3.7 GBq 225 Ac by summer of 2008 was defined. To reach this ambitious goal the task was divided into several sub-task that are: the conversion of the cyclotron to a H -machine with an external beam line, an automated target irradiation facility including an automated transport system of the irradiated targets to the chemistry hot cells, construction of a chemistry laboratory with 5 hot cells to separate 225 Ac from 226 Ra and to recuperate and refine 226 Ra for production of new targets.
Results and Discussion: At the time of submission of this abstract, all relevant processes were developed or nearing completion. In our contribution first results concerning the production of smaller amounts of 225 Ac will be discussed and an outlook to a ramp-up to therapeutically viable amounts will be given.