Intermediate Dose of IV MTX as CNS Prophylaxis for High Risk DLBCL

Central nervous system (CNS) relapse is a devastating event of diffuse large B cell lymphoma (DLBCL). It occurs in 4%-7% of DLBCL in general and the rate is considerably higher in high-risk patients, resulting in a poor outcome.Effective methods of CNS prophylaxis have not yet been developed. Evidence for intrathecal or intravenous MTX are both controversial. In one previous study of PUMCH, IV MTX at a dose of 1g/m2 could significantly decrease the 2 year CNS relapse rate of high risk DLBCL(1.1% vs 12.1% for historic cohort, P=0.003). In current study, the investigators are aiming to confirm its efficacy through phase III study with intrathecal MTX as the controlled arm.