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 ((89)Sr), 153-samarium-EDTMP ((153)Sm), 186-rhenium-HEDP ((186)Re), 188-rhenium-HEDP ((188)Re), and 223-radium-chloride ((223)Ra). 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 (89)Sr, 7 (153)Sm, 12 (186)Re, 2 (188)Re, and 2 (223)Ra; 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%