Case Series Evaluation of Efficacy and Side Effects after Administration of Radium Chloride (223RaCl2) Injection in Elderly Castration-Resistant Prostate Cancer Patients with Bone Metastases

Abstract

Radium chloride ( 223 RaCl 2 ) injection (Xofigo ® infusion) is used as an internal irradiation therapeutic drug for castration-resistant prostate cancer (CRPC) with bone metastases. In this case series evaluation of five elderly patients with CRPC, pain and clinical laboratory tests, such as hematotoxicity (leukocyte count, platelet count, hemoglobin), hepatotoxicity (aspartate aminotransferase (AST), alanine aminotransferase (ALT), prostate-specific antigen (PSA), alkaline phosphatase (ALP), and digestive organ toxicity were retrospectively evaluated up to 6 months after 223 RaCl 2 administration. No patient required strong opioid use during 223 RaCl 2 administration. In two patients, pain aggravated after the last 223 RaCl 2 administration, and narcotic analgesics (controlled-release oxycodone hydrochloride and immediate-release oxycodone hydrate) were used at 17 and 42 days after the last 223 RaCl 2 administration. In hematotoxicity assessment, leukocyte count, hemoglobin, and platelet count decrease of grade ≧ 3 was not found. Two patients experienced transient and mild diarrhea. None of the five patients experienced nausea. Thus, 223 RaCl 2 appears to be a safe drug that could delay pain aggravation in Japanese elderly CRPC patients with bone metastases. However, more cases should be observed in the future.