(UroToday.com) The European Society of Medical Oncology (ESMO) 2021 annual meeting’s prostate cancer session included a presentation by Dr. Nuria Romero-Laorden discussing the final results of PRORADIUM, a study assessing the role of serum biomarkers of bone metabolism in mCRPC patients treated with radium-223. Radium-223 is a life-prolonging alpha-emitter bone targeted therapy for mCRPC patients with bone metastases.1 However, evidence on biomarkers that may help in patient selection are lacking. Total ALP appeared to be a potential marker of radium-223 effect in early studies.2 Other bone-related markers, such as bone-specific ALP, have also demonstrated their prognostic value in mCRPC patients with bone metastases.3,4 The hypothesis of this study was that bone-related markers may affect the clinical outcome of mCRPC patients treated with radium-223.