[Experimental study on osteosarcoma of local chemotherapy diffusing from surgical acrylic cement and plaster].

An experimental study has been made to explore the possibility of using plaster or surgical cement as a vehicle for the diffusion of local chemotherapeutic agents in osteosarcoma. In vitro, leeching out of methotrexate from plaster or acrylic cement occurred with a peak during the first few hours followed by a decreasing curve lasting for an average of two weeks. In dogs suffering from a spontaneous osteosarcoma, the loss of substance produced by excision was filled with cement to which methotrexate had been added extemporaneously. This method of administration produced a general diffusion of methotrexate whose blood levels were measured for three to five days. In laboratory rats into which osteosarcomata had been grafted, tablets of plaster containing antimitotic drug were implanted into the tumour, which was left in situ. This made it possible to show that the local chemotherapy was having a true effect, particularly when the antimitotic used was cisplatinum. In patients who had acrylic cement containing methotrexate inserted during operation, local diffusion resulted in very high concentrations, evidenced by the concentration found in fluid obtained from suction drains during the early days after operation.