DOTMP (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetramethylene-phosphonate) is a macrocyclic chelating agent with superior binding properties to Sm when compared with EDTMP (Quadramet™, used for palliative treatment of bone cancer)...Carboplatin chemotherapy (300 mg/m2 IV every 3 weeks ×4) started 4 weeks after Sm-DOTMP injection...All dogs completed study monitoring. The recommended dose for CycloSam in dogs is 1.75 mCi/kg, which resulted in some pain control with minimal toxicity and was safely combined with chemotherapy.