Lenalidomide Maintenance Treatment in Patients With Primary Central Nervous System Lymphoma

The study will include 28 patients with primary CNS DLBCL who are ineligible with autologous hematopoietic stem cell transplantation or whole brain radiation therapy as consolidation therapy. Induction treatment will include Rituximab and high dose methotrexate protocol (containing at least methotrexate and one more chemotherapy agent). 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 a maximum of 12 cycles, withdrew consent, the disease progressed, or unacceptable toxic effects occurred.