Radiopharmaceuticals for Palliation of Bone Pain in Patients with Castration-resistant Prostate Cancer Metastatic to Bone: A Systematic Review

Context: The majority of patients with castration-resistant prostate cancer develop bone metastatic disease. It is often challenging to optimally palliate malignant bone pain. In case of multifocal pain due to diffuse osteoblastic metastases, treatment with bone-seeking radiopharmaceuticals can be considered. Objective: This systematic review evaluates the efficacy of different bone-seeking radiopharmaceuticals for palliation of malignant bone pain from prostate cancer. Evidence acquisition: The PubMed (Medline) and Embase databases were searched for publications on 89-strontium-chloride (Sr-89), 153-samarium-EDTMP (Sm-153), 186-rhenium-HEDP (Re-186), 188-rhenium-HEDP (Re-188), and 223-radium-chloride (Ra-223). Randomised controlled trials and prospective cohort studies were included. Metastatic bone pain had to be registered as outcome measure for prostate cancer patients separately. Evidence synthesis: This review included 36 articles of which 13 randomised trials and 23 prospective studies. Of all trials, 10 studies used Sr-89, 7 Sm-153, 12 Re-186, 2 Re-188, and 2 Ra-223; three reported on a combination of different radionuclides. Only a few trials contained a blinding procedure and several studies contained incomplete follow-up or lack of intention-to-treat analysis. It was not possible to calculate a pooled estimate of pain response to treatment with any of the radionuclides because different definitions of pain response were used. Conclusions: Overall, pain response percentages greater than 50-60% were seen with each radionuclide. Haematological toxicity was reported in 26 of the 36 studies and more than half of these trials stated no grade 3/4 leukopenia or thrombocytopenia occurred. Patient summary: In this report we reviewed the efficacy of bone-seeking radionuclides for treating bone pain from metastatic prostate cancer. Overall, treatment with bone-seeking radionuclides resulted in pain responses greater than 50-60%. (C) 2015 European Association of Urology. Published by Elsevier B.V. All rights reserved.