Radioactive ion beams for biomedical research and nuclear medical application

In this article a review is given on the research strategies, on experimental work and application of ISOLDE produced radionuclides used in the field of biomedicine over a period of more than 2 decades. Special attention will be directed to the radio-lanthanides for several reasons: firstly, the radio-lanthanides are three-valent metallic radionuclides which show any radiation properties we wish (single photon emission suitable for SPECT, positron emission suitable for PET, beta (-)- and Auger electron emission suitable for therapy). Even the alpha decay mode (suitable for therapy in selected cases) is available in the lanthanide group. Secondly, the 15 lanthanides can be seen chemically as one single element for labelling of tracer molecules, providing the unique possibility to study systematically relationships between physico-chemical molecule parameter and a biological response without changes in the basic tracer molecule. Very recent developments in bioconjugation chemistry call for three-valent metallic radionuclides for all kinds of nuclear medical application: diagnosis, in vivo dosimetry and radionuclide therapy where the rare-earth elements will play an important role in future.