ABSTRACT
Background: Samarium153 EDTMP, a beta and gamma emitter, is used in the palliative therapy of painful bone metastases. Aim: To evaluate the analgesic effects and myelotoxicity of Samarium153 EDTMP in patients with prostate, breast and renal carcinoma. Patients and methods: Twenty patients with bone metastases (11 males), aged 65 years old as a mean, received a 1 to 2 mCi/kg intravenous dose of Samarium153 EDTMP, produced in Chile. Patients were followed thereafter during 4 to 40 weeks. Pain was assessed using a visual analogue scale. Results: Pain decreased from a score of 6.4 prior to treatment, to 2.7 at the fourth week of therapy and the effect lasted a mean of 12.5 weeks. Myelotoxicity was observed in 68percent of cases (WHO stage I in 21 percent, stage II in 37 percent, stage III in 11percent and no patients in stage IV). Platelets were the most affected series and neutrophils the least affected. Cell counts returned to normal between the sixth and eighth week. Seventy nine percent of patients decreased their basal analgesic therapy at the sixth week and 88percent did so at the eighth week. Forty one percent of these patients discontinued all analgesics. Conclusions: Samarium153 EDTMP is effective in the treatment of pain in patients with bone metastases and its myelotoxicity is low to moderate. It should be considered as a therapy for this type of pain, with the precaution of performing periodical bood counts
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Samarium/pharmacokinetics , Bone Neoplasms/drug therapy , Neoplasm Metastasis/drug therapy , Radioisotopes/pharmacokinetics , Pain/drug therapy , AnalgesiaABSTRACT
153 SmEDTMP was obtained from enriched 153Sm irradiated at the 5 MW Chilean Research reactor and labelled at a molar ratio of 15:1 pH 7.5. Biodistribution, autoradiography, radiochemical purity tests were done for evaluation. 40 patients were treated with 37-55 MBq/kg weight. Bone scans using 99mTcHMDP were obtained prior and after treatment. Bone marrow depression was observed in 37 percent of them and normal liver function in all of them. In 45 percent the pain dissapear completely, in 22,5 percent significantly decreased and partially in 30 percent. In 17 patients more than one dosis was injected. Our preliminary results indicate that 153 SmEDTMP is a promising radiotherapeutic agent for palliative treatment of metastasic bone cancer pain and encourage its use specially because it can be produced in countries with low economic resources, thus a large number of patients can get the benefits of this new procedure