- Regimen B: Patients receive consolidation chemotherapy as in regimen A for 3 courses. Patients also receive rituximab IV on days -3 to -1 of course 3 of chemotherapy. Patients undergo leukapheresis at the completion of course 3 (G-CSF continues from day 5 until the end of leukapheresis). After completion of leukapheresis, patients begin a regimen of high-dose chemoradiotherapy comprising either total body irradiation twice daily on days -10 to -7 and ifosfamide IV over 1 hour and etoposide IV continuously on days -6 to -2 or BEAM chemotherapy comprising carmustine, etoposide, cytarabine, and melphalan. Autologous peripheral blood stem cells (APBSC) are reinfused on day 0. Patients also receive G-CSF SC daily beginning on day 5 and continuing until blood counts recover. Beginning on day 42 post-APBSC, if blood counts have recovered, patients receive rituximab IV once weekly for 4 weeks. Rituximab is repeated beginning on day 180 in the absence of disease progression.