[An experimental study of chemoembolization for VX2 bone tumors]

An experimental study of preoperative chemoembolization using cis-platinum crystals was performed in rabbit to test a drug delivery system used for malignant musculoskeletal tumors. The cis-platinum was crystallized from solution, and injected into the animals. The average crystal size was 393 x 222 microns, and their properties were the same as the properties of the solution. A VX2 bone tumors was transplanted into the distal femoral metaphysis of a rabbit in the form of a tumor cell suspension. A total of 20 rabbits were divided into four groups. In one group (Group A), chemotherapy was not used to treat the tumor. In the second group (Group B), a cis-platinum solution was injected into a subcutaneous vein at one week after the VX2 transplantation. In the third group (Group C), a cis-platinum solution was injected into the proximal femoral artery. In the fourth group (Group D), cis-platinum crystals were injected into the proximal femoral artery and a tourniquet was applied to prevent blood flow to the knee (below the tumor) during the injection. X-rays and arteriograms were performed periodically. At 3 weeks after the transplantation, the rabbits were sacrificed and the lesions were examined histopathologically. Serial body weights and tumor growth were also assessed. The X-rays and arteriograms in Groups C and D showed less destruction of the adjacent bone, and less vascularity in the tumor than those in Groups A and B. Wide degenerative or necrotic areas inside the tumor were observed macroscopically in Groups C and D. Focal necrosis was most frequently observed microscopically in Group D. It was concluded from the results of this experimental study that chemoembolization was an effective preoperative procedure that could be used as a drug delivery system to treat a malignant musculoskeletal tumor.