This study suggests that R-IDARAM combined with intrathecal immunochemotherapy may be high effective in primary central nervous system lymphoma (PCNSL) patients.

The investigators will evaluate response rate, progression free survival (PFS), overall survival (OS), and toxicity in primary central nervous system lymphoma (PCNSL) after systemic and intrathecal immunochemotherapy with deferred radiotherapy.

Inclusion criteria:

• Newly diagnosed histologically proven non-Hodgkin's lymphoma (NHL).

Exclusion criteria:

• Involved sites other than the brain, meninges, CSF, or the eyes.
• Age less than 18 years or greater than 75 years.
• Inadequate bone marrow capacity (defined as neutrophils<1.5 ×10^9/L, platelets <100 ×10^9/L, and hemoglobin level< 8 g/dL).
• Known cause of immunosuppression (ie, HIV type I infection).
• Any previous malignancy.
• Creatinine clearance below 60 mL/min.
• Heart insufficiency (NYHA IIIB or IV).
• Uncontrolled infection.
• Noncompensated active pulmonary or liver disease.
• Previously treated for PCNSL, except by corticosteroids.