Ifosfamide/Carboplatin/Etoposide/Rituxan Followed by Zevalin in Relapsed/Refractory Intermediate Grade B-Cell Lymphoma

Inclusion Criteria: To be included in this study, you must meet the following criteria: * Intermediate grade CD20-positive B-cell non-Hodgkin's lymphoma * Persistent lymphoma after one or two previous chemotherapy regimens * Patients should not be considered candidates for high-dose chemotherapy * Ability to perform activities of daily living with assistance * Measurable or evaluable disease * Age \> 18 years * Adequate bone marrow, liver and kidney function Exclusion Criteria: You cannot participate in this study if any of the following apply to you: * Patients with impaired bone marrow reserve * Female patients who are pregnant or lactating * Serious active infection at the time of treatment * Any other serious underlying condition * Brain or meningeal) with lymphoma * HIV or AIDS-related lymphoma * Received external beam radiation therapy to \> 25% of active bone marrow. * History of other cancers, either active or treated Please note: There are additional inclusion/exclusion criteria. The study center will determine if you meet all of the criteria. If you do not qualify for the trial, study personnel will explain the reasons. If you do qualify, study personnel will explain the trial in detail and answer any questions you may have.