REACTOR-PRODUCED RADIOISOTOPES FROM ORNL FOR BONE PAIN PALLIATION

The treatment of painful skeletal metastases is a common clinical prob lem, and the use of therapeutic radionuclides which localize at metast atic sites has been found to be an effective method for treatment of p ain, especially for multiple sites for which the use of external beam irradiation is impractical. There are currently several metastatic-tar geted agents radiolabeled with various therapeutic radionuclides which are in various stages of clinical investigation. Since neutron rich r adionuclides are produced in research reactors and often decay by emis sion of beta(-) particles, most radionuclides used for bone pain palli ation are reactor-produced. Key examples of radionuclides produced by single neutron capture of enriched targets include rhenium-186 and sam arium-153. In addition, generator systems are also of interest which p rovide therapeutic daughter radionuclides from the decay of reactor-pr oduced parent radionuclides. One important example is rhenium-188, ava ilable from generators via decay of reactor-produced tungsten-188. Tin -117m is an example of a reactor-produced radionuclide which decays wi th the emission of low-energy conversion electrons rather than by beta (-) decay. Each of these agents and/or radionuclides has specific adva ntages and disadvantages, however, the ideal agent for bone pain palli ation has not yet been identified. The goal of this paper is to briefl y review the production and use of several reactor-produced radionucli des for bone pain palliation, and to discuss the role of the ORNL High Flux Isotope Reactor(HFIR) for the production of many of these radion uclides. Published by Elsevier Science Ltd.