Combination of External Beam Radiotherapy With 153Sm-EDTMP to Treat High Risk Osteosarcoma

"Subjects receive a tracer infusion of Samarium-153 EDTMP at 1 mCi/kg. 3D dosimetry using SPECT images are obtained post tracer infusion to determine the distribution of dose delivered to the tumor and surrounding normal tissues. Tracer activity will be applied to development of the external beam radiation (EBT) planning. Second treatment infusion of Samarium will then be implemented. Maximum activity administered will be 30 mCi/kg."

"Administered 14 days after Treatment infusion of Samarium-153 EDTMP."

"The radiotherapy portion of the combined plan will be delivered according to the judgement of the treating radiation oncologist. The total dose to be used will be modified based on surrounding tissue tolerances as evidenced by Samarium infusion and SPECT image planning.~After the treatment infusion, SPECT scans will again be performed to confirm the total dose delivered and subsequently adjust the EBT portion of the treatment plan, as necessary."