Nordic Study in Newly Diagnosed Primary Central Nervous System (CNS) Lymphoma

Inclusion Criteria: * Pathologically verified primary central nervous system lymphoma No prior PCNSL treatment. * Patients treated with steroids alone are eligible * No signs of lymphoma outside the CNS * ECOG performance status 0-4 * Age \> 17 and \< 76 years * Written informed consent from the patient or guardian Exclusion Criteria: * Cardiac failure \> 3 * Pregnancy or lactation. Women of childbearing potential are requested to use an effective method of contraception to avoid pregnancy for a period from entry to the study and at least 3 months after the last study medication * Previous malignancy unless disease free for at least five years * Active infection. * Regarding tuberculosis, patients at risk should be tested for latent TB according local practice at each treating centre. * Positive HIV status * Organ transplantation * Serious psychiatric illness * Prior radiotherapy to the brain * Concomitant anti-inflammatory medication that cannot be discontinued * Creatinine clearance \< 60 ml/minute calculated by Cockcroft and Gault formula * Peripheral blood count with granulocytes \<1.5 x 109L or platelets \< 100 x 109L * Serum bilirubin \>1.5 times or ASAT and alkaline phosphatase \>2 times upper limits of normal. * Known anaphylaxis or IgE-mediated hypersensitivity to murine protein or any component of Rituximab excludes patients from Rituximab treatment, but not from the remaining part of the study