Strontium 89 therapy and relief of pain in patients with prostatic carcinoma metastatic to bone: a dose response relationship?

Reports published in the English literature of clinical trials utilizing intravenous strontium 89 (89Sr) in the treatment of patients with prostatic adenocarcinoma metastatic to bone were reviewed. Correlation coefficients were calculated for increasing dose of 89Sr and complete pain relief and complete and partial pain relief. Statistically significant positive correlations were obtained for complete relief of pain. Positive correlations were also found between those patients who had at least partial pain relief (defined as at least a 50% reduction in analgesia requirement), but these did not reach significance. This analysis suggests that a dose response relationship may exist between the dosage of 89Sr administered, and complete relief of pain due to skeletal metastases. The optimal dosage of 89Sr in this clinical situation has not been established, and prospective, carefully executed and analyzed randomized trials will be required to test whether and to what extent dose intensity of 89Sr determines outcome independently of other factors.