Radium-223-dichloride is approved therapy for patients with metastatic castration-resistant prostate cancer and bone metastases. Therapy is administered intravenously every 4 weeks for up to 6 cycles. More than 20 % of patients treated at Rigshospitalet develop bone marrow suppression as a side effect to Radium therapy, which delays or excludes the patient from further oncological therapy. Especially thrombocytopenia is a frequent side-effect and can be long lasting.