153Sm-EDTMP for Pain Relief of Bone Metastases from Prostate and Breast Cancer and Other Malignancies

Background and Aims Approximately 85% of patients with cancer suffer severe metastatic bone pain for which radionuclide therapy has been employed for pain palliation. We undertook this study to evaluate the pain relief effect of 153 Sm-EDTMP in Mexican patients with severe and painful bone metastases from mainly prostate, breast, and renal cancer and other malignancies. Methods Patients (277) with intense sustained pain caused by bone metastases were referred to the Nuclear Medicine Department of the Oncology Hospital of the Mexican Social Security Institute. The patients had to have acceptable physical conditions, a previous positive 99m Tc-MDP scan and blood values within normal range. 153 Sm-EDTMP was prepared at the Instituto Nacional de Investigaciones Nucleares (ININ) and 37 MBq/kg of body weight was injected intravenously. Pain palliation was evaluated with a visual analogue scale (VAS) and a verbal rating scale (VRS) before treatment and 3 and 12 weeks after treatment was started. Results The age interval of the patients was 24–92 years with a mean age of 64 ± 12 years. Mean values for hemoglobin, leukocyte and platelet counts did not statistically differ at zero time, 3 and 12 weeks after treatment. Pain intensity and relief assessment were statistically different: 9.1 ± 0.61 units initially; 4.2 ± 1.3 units 3 weeks later (54%) and after 12 weeks the pain diminished to 2.4 ± 1.4 units (74%) in the pain relief score scales. Conclusions 153 Sm-EDTMP was readily available, safe and well tolerated. We conclude that 153 Sm-EDTMP was an adequate palliative agent and was the best option for our Mexican patients to relieve their severe metastatic bone pain.