Treatment of initial parenchymal central nervous system involvement in systemic aggressive B-cell lymphoma.

Central nervous system (CNS) involvement in systemic B-cell non-Hodgkin lymphoma (B-NHL) at diagnosis (sysCNS) is rare. We investigated the outcome of 21 patients with sysCNS, most commonly diffuse large B-cell lymphoma, treated with high dose methotrexate (HD-MTX) and R-CHOP. The median number of cycles of HD-MTX and R-CHOP was 4 (range 1-8) and 6 (range 0-8), respectively. Consolidative whole brain radiotherapy (WBRT) was given to 33% (7/21) patients. With a median follow-up of 44 months the 3-year progression free survival (PFS) and overall survival (OS) were 45% (95%CI 34-56%) and 49% (95%CI 38-60%), respectively. Over 90% of patients had an unfavorable international prognostic index score, reflected by treatment-related mortality of 19% (4/21) and relapse-related mortality of 28% (6/21). The outcome of these patients was, however, unexpectedly good when compared to secondary CNS relapses. Prospective studies are needed to define the optimal treatment for patients with sysCNS, but its rarity might be challenging.