Theranostics: Advancing Targeted Alpha Therapy with Astatine

Abstract

Theranostics is an emerging concept that integrates therapeutics and diagnostics. It can be implemented by switching the radionuclide of the same compound from one used for diagnostic imaging to one used for radioligand therapy. In diagnostic imaging, for example, not only can the expression levels of target molecules in metastatic lesions throughout the body be quantitatively assessed, but the effectiveness of treatment can also be predicted. In particular, in drug development, it is possible to optimize therapeutic agents based on the biodistribution of diagnostic compounds, thereby reducing physiological accumulation in normal organs and minimizing side effects. For treatment, RI-labeled ligands are delivered to target sites in the same way as diagnostic agents and can treat cancer from within the body using short-range radiation such as alpha or beta particles. In Japan, we are at the forefront of drug development and clinical applications using astatine-211 (¹¹At), which can be produced by cyclotrons, and further advances are anticipated.