Lenalidomide Maintenance Treatment in Patients With Primary Central Nervous System Lymphoma

Patients with MRI documented response CR or PR after induction chemotherapy will enter the study protocol of lenalidomide maintenance (at a dose of 15 mg per day, on days 1 to 21 of each 28-day cycle) for up to 12 cycles or until the patients withdrew consent, the disease progressed, or unacceptable toxic effects occurred.