Abstract
Primary central nervous system (CNS) lymphoma is no longer not a rare tumor in even immunocompetent hosts. Radiotherapy can achieve high response rates in most patients with CNS lymphoma, but the survival is usually only 12-18 months because the tumor recurs. In this study the addition of intravenous high-dose methotrexate (HDMTX) prior to irradiation markedly improved the time of both tumor-free and overall survival. Other chemotherapeutic agents such as CHOP (cyclophosphamide, doxorubicin, oncovin, prednisone) and nitoroureas were ineffective. Rapid infusion of HDMTX (rapid HDMTX) resulted in more enhanced penetration into cerebrospinal fluid and reduced the tumor volume much more significantly than regular infusion of the drug (regular HDMTX). The rapid HDMTX yielded a median survival of at least 60 months and 5 year survival rates of 62%. There was no difference in acute side effects including bone marrow suppression between rapid HDMTX and regular HDMTX. Late neurotoxicity such as progressive dementia occurred in 15-16% of patients in both treatment groups. High-does chemotherapy of rapid intravenous infusion of MTX is very effective in the treatment of CNS lymphomas, but the issues of neurotoxicity, drug-resistance and possible combination drugs need to be addressed in future.
