[Therapy of solid tumors using high-dose methotrexate and citrovorum factor]

Methotrexat (250-1100 mg/m2) was administered to 38 patients with malignant tumors by infusion of either 6 hours or of 75 minutes duration. MTX-infusion and continued at 3-6 hours interval for Citrovorum factor rescue was started 2 hours after 24 to 72 hours. 7 different MTX doses and rescue schedules were tested. It could be shown that MTX in the dose range used is effective in various tumors when CF-rescue is not higher than 7% of the administered MTX-dose, only occasionally therapeutic success was observed with higher doses. In the group of patients where CF-rescue was lower than 7% of the MTX dose on 9/14 patients objective tumor-regressions could be achieved. Conclusions drawn are discussed and the necessity of further investigations is emphasized.