Targeted alpha-particle therapy of microscopic disease: Providing a further rationale for clinical investigation.

As is the case with diagnostic nuclear medicine, a major consideration in the development of targeted radiotherapeutics is to seek a balance between conceptual elegance and practicality. Nowhere is this more apparent than in the selection of the nature of the radiation to be exploited and the radionuclide that will be used to deliver this radiation. From a pragmatic perspective, convenient availability and distribution of the radionuclide at a reasonable cost are paramount. The multiday half-life b-emitters 131I and 90Y are notable examples and it is not coincidental that the first 2 Food and