Astatine-211-Towards In Vivo Stable Astatine-211 Labeled Radiopharmaceuticals and Their (Pre)Clinical Applications.

Targeted radioligand therapy has emerged as a promising treatment option for eradicating advanced cancer forms. α-Emitters are considered particularly promising as they can obliterate (micro)-metastases. The α-emitter astatine-211 (At) has experienced increased interest due to its favorable decay properties. As a result, various At-astatination strategies have been developed to address challenges associated with working with this "halogenic metalloid." This review summarizes efforts to produce and scale At, describes its physicochemical properties, discusses the advantages and disadvantages of using a radionuclide with a half-life of 7.2 h and outlines procedures for astatinating radiopharmaceuticals. Moreover, a key focus of this review is to rationalize strategies aimed at minimizing in vivo deastatination. A brief overview of on-going (pre)clinical development with At-labeled radiopharmaceuticals is provided. Astatinated radiopharmaceuticals will play a pivotal role in cancer management in the near future when challenges related to scalability and in vivo stability have been addressed and clinical studies have shown the benefit of At compared to longer-lived therapeutic radionuclides.