Radiolabeled compounds in the development of cytotoxic agents.

With the help of radiolabeled compounds, drug development can be made faster; especially with microdosing and radiopharmacokinetics, some elements of phase I and II trials necessary for conventional cancer drug development can be avoided. Imaging may proof the principle of actual targeting. However, radiopharmacokinetics is dependent on the radionuclide, the radionuclide linker with the drug and the size of the drug molecule. Optimally, some of the drug molecule atoms may be replaced with a radionuclide that can be visualized. In this article drug development utilizing radionuclides both in PET and SPET has been reviewed.