Update: molecular radiotherapy: survey and current status.

Molecular radiotherapy (MRT) is founded on the ability to identify or synthesize radionuclide carriers that recognize and bind to tumor-associated target molecules. Advances in our understanding of the molecular biology of cancer and other diseases have identified molecules and signaling pathways that we can now visualize, in vivo, for diagnosis, staging, and to identify optimal therapy and monitor patient response to therapy. These advances have also helped identify targets for MRT, making it possible to target radiation at the cellular and molecular level. MRT is typically administered systemically, intracavitary, or locoregional administration has also been examined. In contrast to chemotherapy, wherein all proliferating cells are affected, MRT delivers radiation to only those cells that express cancer markers.