Production logistics and radionuclidic purity aspects of Sm-153 for radionuclide therapy

Sm-153, an attractive therapeutic radionuclide, was produced by neutron activation of both natural Sm2O3 and 98% enriched (Sm2O3)-Sm-152 targets. The production logistics and radionuclidic purity aspects of Sm-153 obtained using both these targets are discussed with respect to the intended end use for metastatic bone pain palliation (MBPP) in terminal cancer patients and radiation synovectomy (RS) of medium size joints. The: specific activity of Sm-153 obtained was around 11 GBq.mg(-1) (approximately 300 mCi.mg(-1)) and 44 GBq.mg(-1) (approx. 1200 mCi.mg(-1)) from natural and enriched targets, respectively. The level of the long-lived radionuclidic impurity burden in Sm-153 obtained from the natural Sm2O3 targets, namely, due to Eu-154 (5 Bq.MBq(-1) Sm-153 (5 nCi.mCi(-1) Sm-153)) and Eu-155 (75 Bq.MBq(-1) Sm-153 (75 nCi.mCi(-1) Sm-153)), appears low enough not to pose a problem, both in the palliative treatment of terminal cancer patients (at 1.85-2.22 GBq (50-60 mCi) dose) as well as in RS (at 74 MBq (2 mCi) dose). The Eu-154 content in Sm-153 from the enriched target was comparable, while, as expected, the level of Eu-155 was nearly two orders of magnitude lower. There is a notable overall advantage of Sm-153 over the use of Re-186, the other radionuclide of interest for the same purposes. ((C) 2002 Lippincott Williams & Wilkins).