Clinical Role of Sm-153 EDTMP in the Treatment of Painful Bone Metastatic Disease

Abstract

Sm-153 EDTMP is an effective treatment of painful bone metastases from different neoplasms. However, there are few studies describing clinical experience with this therapeutic modality. The aim of this clinical study was to evaluate the efficacy of Sm-153 EDTMP in a group of patients with skeletal metastases and poor pain control with conventional therapies. Sixty-four patients with painful bone metastases treated with Sm-153 EDTMP were retrospectively evaluated. Nine patients were treated twice. The most common primaries were breast in 28 cases (44%) and prostate in 27 (41%). Treatment efficacy was assessed by a visual analog scale, analgesic consumption, and performance status before and after treatment. Response was graded as complete, moderate, or minor. Toxicity evaluation included analytic parameters (blood counts, renal function) and clinical follow up. Efficacy and toxicity were evaluated separately for each dose (total doses: 73), and complete follow up was only possible in 62 of 73 administrations. The response rate was 85% (21% complete, 40% moderate, and 24% minor). Onset of improvement took place a median of 7 days after Sm-153 EDTMP administration, and pain relief persisted for a mean of 3 months. No relevant toxicity was found in the early phase. Myelotoxicity appeared in 29% of the administrations and was mild in most cases (there was one case of grade 4 leukopenia). Sm-153 EDTMP is a good therapeutic option for patients with painful bone metastases. It is an effective treatment of pain relief without major secondary effects.