In the presently planned multicentre Phase III trial the two therapies will be compared: Patients will be randomized after intensified induction treatment with 4 cycles rituximab, methotrexate, cytarabine and thiotepa (MATRix) between first-line high-dose chemotherapy against conventional consolidating therapy with 2 cycles of conventional chemotherapy with R-DeVIC (rituximab, dexamethasone, etoposide, ifosfamide, carboplatin).