Diagnostic and therapeutic radioisotopes: selection and production

The use of radioisotopes in imaging and therapy became a well established and important clinical praxis. The predominant radioisotopes are 99mTc and 90Y in diagnostics and 131I in therapy. Considerable efforts are devoted to elaborate techniques and methods to produce new radioisotopes and radiopharmaceuticals for specific applications. At present, there are about fifteen radioisotopes available on the commercial basis. Many others are under investigation for the routine and novel applications. The condition for a radioisotope to become a clinical reality depends not only on its physical, chemical and biological properties and behaviour. It should also be available in sufficient activities and adequate quality and at reasonable price. In the paper given are the considerations regarding the criteria for the selection of diagnostic and therapeutic radioisotopes. Some novel developments and improvements in their production are also included. (author)