Seven (7) days after the 90Y Zevalin injection, you will receive the BEAM combination of chemotherapy. You will receive carmustine (over 2 hours) on Day 1 of chemotherapy. You will receive cytarabine (over 2 hours) followed by etoposide (over 4 hours) twice a day on Days 2 through 5. On Day 6, you will receive melphalan (over 20 minutes). A catheter (small flexible tube) will be placed in a large vein in your chest so that the chemotherapy drugs can be given to you more easily. This is called a central venous catheter. All of the chemotherapy drugs will be given through the central venous catheter.