Significant reduction of the mass of bone metastasis 1 year after rhenium-186 HEDP pain palliation therapy.

A 59-year-old man with prostate cancer and pain from multiple bone metastases was treated with 1,424 MBq (38.5 mCi) rhenium-186 hydroxyethylidene diphosphonate (Re-186 HEDP). In addition, he had nonsteroidal antiandrogen, progestagen, and an analog-luteinizing hormone. Neither chemotherapy nor external-beam radiotherapy was administered. Bisphosponate therapy was stopped 4 weeks before the administration of Re-186 HEDP. The Tc-99m HMDP whole-body scan obtained 6 weeks after therapy showed the same results as before therapy. However, 1 year after therapy, a significant reduction of the mass of the metastases was visible on bone scan. The bone scan index decreased from 34 before therapy to 10 after 1 year. The patient described significant pain relief and stopped his analgesic intake 3 weeks after therapy.