The purpose of this study is to evaluate two types of chemotherapy for primary central nervous system lymphoma in the elderly (age older than 60) :

• Methotrexate, procarbazine, vincristine and cytarabine
• Methotrexate and temozolomide

The aim of the study is to evaluate efficacy and toxicity associated with both protocols in this population, without radiotherapy.

Patients will be randomized to receive one of the two regimens in one of the participating centers. Neuropsychological evaluation will be performed in all patients. Patients will be followed with serial MRIs.

Inclusion Criteria:

• primary central nervous system lymphoma histologically confirmed by brain biopsy, CSF cytology or vitrectomy
• KPS 40 or higher
• 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 > 40 ml/min
• Age ≥ 60 years
• Negative HIV test
• Signature of informed consent

Exclusion Criteria:

• previous cranial radiotherapy
• 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