[A multicenter study to determine the efficacy and safety of strontium (89Sr) chloride for palliation of painful bony metastases in cancer patients].

Purpose: A multicenter study was conducted to evaluate the efficacy of strontium chloride (89SrCl2) for palliation of painful bony metastases using the Visual Analogue Scale (VAS), Brief Pain Inventory (BPI) and Functional Assessment for Cancer Therapy-General (FACT-G).

Methods: Ninety patients received a single injection of 2.0 MBq/kg and were classified as responders if VAS scores decreased without increased use of analgesics or if analgesic consumption decreased without an increase in the VAS.

Results: In the 69 subjects that could be evaluated, mean VAS values decreased significantly from 48.0 +/- 20.8 mm at baseline to 24.1 +/- 22.3 mm at last visit(Week 12) (p < 0.0001). VAS decreased more than 10 mm in 58.0% of these subjects, and analgesic consumption was reduced more than 10% in 39.1% of subjects. The response rates were 46.4% (95% confidence interval (CI) 34.3-58.8%) in the 69 subjects that could be evaluated and 43.3% (95% CI 32.9-54.2%) in all subjects. The scoring in BPI for interference in daily life improved together with improvement in its pain scores. Total FACT-G score showed significant improvement, as did its score in the subsection of physical well-being. Both platelets and leucocytes decreased by 22% at nadir (week 8), and such profiles of myelosuppression by 89SrCl2 were similar to those in the previous clinical studies.

Conclusion: These results suggest the clinical utility of 89SrCl2 for pain palliation, which leads to QOL improvement in patients with painful generalized bone metastases.