Abstract
Terbium-161 ((161)Tb) is emerging as a promising theranostic radionuclide for prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (RLT) in metastatic castration-resistant prostate cancer (mCRPC). Compared with lutetium-177 ((177)Lu), (161)Tb emits additional high-linear energy transfer Auger and internal conversion electrons, enabling superior tumor cell kill in micrometastatic disease. Early clinical studies demonstrate favorable safety, dosimetry, and efficacy profiles for (161)Tb-labeled PSMA ligands. Ongoing trials and production advancements are critical to fully realizing the therapeutic potential of (161)Tb-based RLT.