Role of samarium-153-ethylene diamine tetramethylene phosphonate radionuclide bone pain palliation in patients with metastatic bone disease

Background: Bone pain is the most common symptom in advanced stages of malignancy and requires multidisciplinary approach for its treatment. Localized sites of involvement can be treated with surgery or external beam radiation, whereas radiopharmaceuticals, hormones, and chemotherapy are used to treat more diffuse bone involvement. Methods: The present prospective study was undertaken to evaluate the efficacy of pain palliation achieved with samarium-153 (Sm-153) ethylene diamine tetra methylene phosphate (EDTMP) administration. During the period, June 2011 to June 2013, 30 patients with bone pain due to metastatic bone disease were treated with samarium-153 EDTMP. The patients were evaluated with visual analogue scale, Karnofsky performance score and analgesic score, before and after therapy, to assess extent of pain relief. Results: Twenty out of 30 patients (67%) showed response to Sm-153 EDTMP therapy. In this group of patients, statistically significant decrease in pain intensity and drug intake was noted along with improvement of quality of life, which persisted till three months after therapy. Mild myelotoxicity was noted in most patients. Only two patients developed Grade 3 myelotoxicity. Conclusions: Samarium-153 EDTMP is a safe, economical and well tolerated modality of treatment for patients with painful osteoblastic skeletal metastases and has a simple administration procedure. A single dose of Samarium-153 EDTMP provides good pain palliation lasting for several weeks.