A study in The Journal of Nuclear Medicine suggested that circulating tumor DNA profiling can improve patient selection for radium-223 (^223Ra) radiopharmaceutical therapy in metastatic castration-resistant prostate cancer. Researchers reported that a blood-based ctDNA approach flagged which patients are more likely to benefit from ^223Ra. The finding targets a persistent challenge in mCRPC treatment planning: matching radiopharmaceutical therapy to responders rather than treating the population broadly. If validated in larger prospective cohorts, ctDNA-guided selection could reshape dosing decisions and improve efficiency of expensive radiopharmaceutical pathways.