THE IELSG-32 TRIAL: RANDOMIZED PHASE II TRIAL ON PRIMARY CHEMOTHERAPY WITH HIGH-DOSE METHOTREXATE AND HIGH-DOSE CYTARABINE WITH OR WITHOUT THIOTEPA, AND WITH OR WITHOUT RITUXIMAB, FOLLOWED BY BRAIN IRRADIATION VS HIGH-DOSE CHEMOTHERAPY SUPPORTED BY AUTOLOGOUS STEM CELLS TRANSPLANTATION FOR IMMUNOCOMPETENT PATIENTS WITH NEWLY DIAGNOSED PRIMARY CNS LYMPHOMA