Favorable response of metastatic osteogenic sarcoma to pulse high-dose methotrexate with citrovorum rescue and radiation therapy

Ten patients with metastatic osteogenic sarcoma were treated with 6-hour infusions of methotrexate in high dosage. Citrovorum factor was injected 2 hours later and repeated at 6-hour intervals for 12 doses. Methotrexate infusions were repeated at intervals of 2 to 3 weeks. Dosage was escalated until response or toxicity occurred. Doses between 100 and 200 mg/kg of methotrexate resulted in disappearance of pulmonary metastases in two patients and partial regression in pulmonary or bone metastases in two others. Between courses, radiation therapy was administered to five patients, all of whom achieved a partial response. Two patients who relapsed after initial response to chemotherapy alone, responded to subsequent radiotherapy. Toxicity and side effects were unpredictable. Of 57 treatments 30% were followed by stomatitis, 23% by myelosuppression, and 7% by renal abnormalities.