Why bother with alpha particles?

The approval of ${}^{223}$RaCl${}_2$ for cancer therapy in 2013 has heralded a resurgence of interest in the development of $\alpha$-particle emitting radiopharmaceuticals. In the last decade, over a dozen $\alpha$-emitting radiopharmaceuticals have entered clinical trials, spawned by strong preclinical studies. In this article, we explore the potential role of $\alpha$-particle therapy in cancer treatment. We begin by providing a background for the basic principles of therapy with $\alpha$-emitters, and we explore recent breakthroughs in therapy with $\alpha$-emitting radionuclides, including conjugates with small molecules and antibodies. Finally, we discuss some outstanding challenges to the clinical adoption of $\alpha$-therapies and potential strategies to address them.