[A device for rapid elevation of plasma methotrexate (MTX) concentration and its maintenance in high-dose MTX therapy].

For 5 osteosarcomas and one synovial sarcoma, 24 courses of high-dose methotrexate (MTX) therapy were performed. At MTX doses of 300 mg/kg with several infusion patterns, the plasma MTX concentrations were measured by fluorescence polarization immunoassay. In the various types of infusions, five hours oblique and five hours bolus infusions were well maintained at 1,000 micromol/l for several hours. In particular, five hours bolus infusion of MTX needed only 20 minutes to reach 822 micromol/l and maintained 1,000 micromol/l during almost the entire infusion period. Optimization of chemotherapy for sarcomas by MTX requires individual adaptation of the infusion pattern.