(153)Samorium-ethylendiaminetetramethylenephosphonate (EDTMP) has become a treatment of choice for painful bone recurrences. The reasons and the background of the Vienna protocol in 1994 are outlined. A 30 mCi (1.1 GBq) dose exhibits comparable pain palliation with less hematotoxicity as compared to 1 mCi/kg, the conventional dose widely used, the 3 months interval as most of the patients (around 80%) show pain palliation for that period of time. Repeated administration furthermore allows lesion stabilization/regression and a tumor marker response. Other reasons are outlined in detail. The earlier Sm-153-EDTMP is started the better; patients not only experience effective bone pain palliation, but also improved quality of life, lesion stabilization/regression and a prolonged survival.