Radium-223 in the Modern Era: Patient Selection and Sequencing

Despite the expanding range of therapeutic options in mCRPC, radium-223 retains a Category 1 recommendation in the 2026 NCCN guidelines for a well-defined subset of patients. Oliver Sartor, MD, director of the Transformational Prostate Cancer Research Center at East Jefferson General Hospital in Metairie, Louisiana, walks through the key patient selection criteria he applies in practice: the agent works exclusively in bone, meaning patients with significant lymph node or hepatic involvement are not candidates. Equally important, the disease must be osteoblastic—detectable on a conventional bone scan—because radium-223 is taken up by bone-forming lesions. Soft-tissue or purely osteolytic disease is not an appropriate target.
Sartor also highlights data from the phase 3 PEACE III trial, which demonstrated a survival benefit when radium-223 is combined with enzalutamide compared to enzalutamide alone—but with a critical caveat: this benefit was observed in patients without prior ARPI exposure. Given that ARPIs are now routinely used in the hormone-sensitive setting, the applicability of these data to most contemporary patients is an open question.
On sequencing, Sartor acknowledges significant uncertainty around how to position radium-223 relative to lutetium-177 PSMA-617. He notes that emerging data—predominantly from Europe and now from the United States—support the safety of lutetium following radium. He also looks ahead to the ECLIPSE trial, which is expected to provide additional clarity on isotopic sequencing, alongside anticipated data on actinium-225. The radiopharmaceutical landscape continues to evolve rapidly, and sequencing decisions will require ongoing reassessment as new evidence matures.