High-dose methotrexate for non-AIDS primary central nervous system lymphoma. Report of 13 cases

Thirteen patients with primary lymphoma of the central nervous system (CNS) were treated with high-dose intravenous methotrexate (MTX), 3.5 gm/sq m, followed by calcium leucovorin rescue, at 3-week intervals, for three cycles. Eleven patients subsequently received radiation therapy to the whole brain, 30 to 44 Gy. Before radiation therapy, eight patients responded completely and four partially; there was one non-responder. The median Karnofsky score before high-dose MTX therapy was 60 and increased to 90 after treatment. Five of the eight complete responders reached a Karnofsky rating of 100. The three longest responders (one of whom received MTX only) were without recurrence of their disease at 29+, 32, and 32+ months posttherapy. The median response period is 9+ months. The median survival time from the date of the first MTX treatment is 9+ months, and the three longest survival times are 29+, 32+, and 54+ months. All patients received corticosteroids in either unchanging or diminishing dosages during therapy. It is concluded that primary CNS lymphoma is sensitive to high-dose MTX, which provides a safe and easily administered adjuvant to radiation therapy for this neoplasm.