The purpose of this study is to evaluate the efficacy and safety of chemotherapy with MT-R followed by autologous stem cells transplantation in newly-diagnosed primary central nervous system lymphoma.

It's a single center, single arm, prospective clinical trial. Patients younger than 65 years old with primary central nervous system lymphoma will received four cycles of chemotherapy with rituximab plus high-dose methotrexate and temozolomide as induction therapy, and then received consolidation therapy with autologous stem cell transplant for which the conditioning regimen is Carmustine plus thiotepa.

Inclusion Criteria:

• primary central nervous system diffuse large B-cell lymphoma histologically confirmed by brain biopsy
• ECOG 0-2
• Absence of systemic disease as evaluated by chest-abdomen-pelvis CT scan
• Leucocytes>3.500/mm3, platelets>130.000/mm3, Bilirubin < 2 mg, transaminases < 2.5 N), creatinine < 150 μM/l, creatinine clearance > 50 ml/min/1.73m2
• Age 18-65 years
• Negative HIV test
• Signature of informed consent

Exclusion Criteria:

• prior chemotherapy for primary central nervous system lymphoma
• presence of another cancer (excepting basal cell carcinoma of the skin and cervical carcinoma in situ )
• systemic lymphoma (outside the CNS)
• Isolated ocular lymphoma
• Immunosuppressed patients (HIV , use of immunosuppressors)
• Other uncontrolled or progressive disease compromising shot-term survival
• Severe renal or hepatic disease
• Patients not legally covered by the French Social Security
• Inability to swallow the medication