211At-Parthanatine is an alpha-emitting radiopharmaceutical therapeutic that targets poly(adenosine-diphosphate-ribose) polymerase 1 (PARP1) in cancer cells. As a therapeutic, 211At-PTT completes a theranostic pair with companion diagnostic fluorine-18 Fluorthanatrace (18F-FTT), which is currently under evaluation in multiple adult cancers for positron-emission tomography (PET) imaging of PARP-1. 211At-Parthanatine is developed in the indication high-risk neuroblastomas.