Management of metastatic bone pain with repeated doses of rhenium 186-HEDP in patients under therapy with zoledronic acid: a safe and additively effective practice.

PURPOSE: The aim of this study was to compare pain response and hematologic toxicity between single and multiple therapies with (186)Re-HEDP under zoledronic acid in patients suffering from painful osseous metastases from prostate or breast cancer.

MATERIALS AND

METHODS

Forty-five (45) patients received multiple therapies of (186)Re-HEDP (n = 77), under a stable regimen of analgesics and zoledronic acid, far off other therapeutic manipulations, and with no extraosseous disease progression. Hematologic status and pain indices were followed up regularly.

RESULTS

Evaluable patients (n = 12), received 31 (186)Re-HEDP therapies. After the first treatment with (186)Re-HEDP, the mean percentile decrease for hemoglobin was 4.7%, for white blood cells was 21.4%, and for platelets was 12%. After multiple therapies, the respective declines were 7.0%, 16.0%, and 23.4%. With respect to baseline blood counts, only thrombocytes showed a tendency for greater decrease after repeated treatments, yet not of clinical significance. Favorable clinical response occurred after the first therapy in 10 of 12 patients (83.3%), after multiple doses in 15 of 19 (78.9%), and overall in 25 of 31 (80.6%) of (186)Re-HEDP therapies. Significant post-therapy improvement in pain indices was observed in all cases, regardless of the number of therapeutic doses.

CONCLUSIONS

Retreatments with (186)Re-HEDP under zoledronic acid provide continuing effectiveness in metastatic bone pain and are safe enough, if an acceptable baseline hematologic status exists.