Targeted imaging and therapy for bone metastases: control of pharmacokinetics of bone-targeted radiopharmaceuticals

The selective accumulation of radioactivity in the target tissue is important for in vivo radiopharmaceuticals. To establish the requirements for the selective accumulation of radiopharmaceuticals, we have developed radiopharmaceuticals based on the concept of “bifunctional radiopharmaceuticals”, which have a recognition site for the target molecule and a binding site for the radionuclide independently in one molecule. This report focuses on radiopharmaceuticals for palliation therapy of bone metastases and reviews recent efforts toward the development of strategies for the control of the pharmacokinetics of radiopharmaceuticals.