Combined therapy of Sr-89 and zoledronic acid in patients with painful bone metastases.

PURPOSE: We evaluated the pain response and daily discomfort in patients with painful bone metastases treated by merging 89Sr-chloride and zoledronic acid. The results were compared with those of patients who received 89Sr-chloride or zoledronic acid separately. METHODS: 25 patients (12 women; mean age 65+/-13 years) chronically treated with zoledronic acid underwent bone pain palliation with 150 MBq of 89Sr-chloride at least 6 months later that bisphoshonate therapy started (group A). 13 patients (6 women; mean age 70+/-12 years) received 89Sr-chloride alone (group B) and 11 patients (5 women; mean age 69+/-12 years) were chronically treated and continued to receive only zoledronic acid therapy (group C), both constituted the control groups. Patients kept a daily pain diary assessing both their discomfort and the pain of specific sites by using a visual analog scale (VAS), rating from 0 (no d iscomfort-no pain) to 10 (worst discomfort-pain). These diaries were reviewed weekly for 2 months and three different physicians rated the pain response on a scale of -2 (considerable deterioration) to +2 (considerable improvement). RESULTS: Baseline characteristics were similar in the three groups. The reduction of total discomfort and of bone pain in the group A was significantly greater as compared to group B (P<0.01) and group C (P<0.01). During the monitored period, a significant improvement of clinical conditions was observed in the group A, varying the rate from -1 to 1 as compared to both groups B and C in which the rate changed from -1 to 0. CONCLUSION: Our findings indicate that combined therapy of 89Sr-chloride and zoledronic acid in patients with painful bone metastases is more effective in treating pain and improving clinical conditions than 89Sr-chloride or zoledronic acid used separately.