Safety and feasibility of percutaneous vertebroplasty with radioactive 153Sm PMMA in an animal model

PurposeWe investigated the safety and feasibility of the combination of samarium-153-ethylenediamine tetramethylene phosphonate (153Sm-EDTMP)-incorporated bone cement (BC) with percutaneous vertebroplasty (PVP) in dogs.Methods and materials153Sm-EDTMP-incorporated BC was prepared by combining solid 153Sm-EDTMP and polymethylmethacrylate (PMMA) immediately before PVP. It was then injected into the vertebrae of four healthy mongrel dogs (two males and two females) by PVP under CT guidance. Each dog was subjected to five PVP sessions at a 153Sm-EDTMP dose of 30–70 mCi. The suppressive effect of local injection of 153Sm-EDTMP on the hematopoietic system was evaluated through counting of peripheral blood cells. Distribution of 153Sm-EDTMP-incorporated BC and the status of tissues adjacent to injected vertebrae were evaluated with SPECT, CT and MRI. Histopathology was carried out to assess the influence of PVP on the vertebra and adjacent tissues at the microscopic level.ResultsPVP was done successfully, and all dogs exhibited normal behavior and stable physical signs after procedures. 153Sm-EDTMP-incorporated BC was concentrated mainly in target vertebrae, and the peripheral blood cells remained within normal range. The spinal cord and tissues around BC did not exhibit signs of injury even when the dosage of 153Sm-EDTMP increased from 30 mCi to 70 mCi.ConclusionA dose lower than 70 mCi of 153Sm is safe when it was injected into vertebrae. 153Sm-EDTMP-incorporated BC did not influence the effect of PVP. This means might strengthen anti-tumor activity locally for vertebra with osseous metastasis without damaging adjacent tissues.