The spread of tumor-cell-sized particles after bone biopsy

For the purpose of determining possible passive dissemination of tumor cells from a bone biopsy site, we created an animal model. A cortical window was placed in the canine femur and a measured quantity of radioactive microspheres was placed in the medullary canal. Local and distant spread of the microspheres were measured four days after the simulated biopsy. In the animals in which the cortical window was left open, spread of the microspheres was limited to the adjacent tissue and the regional lymph nodes. In the animals in which the bone window was plugged with methylmethacrylate, there was little or no local spread of the microspheres; however, there was significant uptake of the microspheres in the lung. In a separate trial, significant microsphere activity was present in the lung within twenty minutes after placement of the methylmethacrylate plug.