Inclusion Criteria:

- All patients must have a histologic or cytological diagnosis of B-cell lymphoma, and
have failed at least one regimen of standard chemotherapy. All histologic grades of
non-Hodgkin's lymphoma (NHL) will be eligible for these studies.

- Patients must be > 18 years of age

- Measurable disease by CT, with at least one lesion > 1.5 cm in one or both dimensions

- less than 25% bone marrow involvement as determined by bone marrow biopsy

- Patient must have greater than 15% cellularity of the bone marrow.

- Patients must be at least 4 weeks beyond any major surgery.

- Patients must be at least 4 weeks beyond any radiation therapy to the index lesion
and must have recovered from radiation induced toxicity.

- Patients must be at least 4 weeks beyond prior chemotherapy and/or immunotherapy, or
2-weeks after corticosteroids, and their blood counts must be within the eligibility
criteria. Corticosteroids may, however, be given concomitantly if used to treat
adrenal insufficiency

- Patients must have a performance status of 70 or greater on the Karnofsky scale
equivalent to ECOG 0-1 (See Appendix A) and a minimal life expectancy of 6 months.

- Patients must be able to give cognizant informed consent.

Exclusion Criteria:

- Patients with a significant concurrent medical complication including severe
anorexia, nausea or vomiting that in the judgement of the Investigator could affect
the patient's ability to tolerate or complete this study.

- Patients with metastasis to the brain.

- Patients with extensive irradiation to more than 25% of their red marrow will be
excluded, except those who had total body irradiation in the context of bone marrow
or stem cell transplantation regimen with subsequent engraftment of a functional
marrow (i.e., resulting in normal peripheral blood counts). Subjects who have
received external radiation to specific organs or areas at the maximum tolerated
level are also excluded.

- Women who test positive for pregnancy.

- Patients with splenomegaly.

- Patients with > 4 treatment regimens prior to this protocol, including chemotherapy,
radiotherapy and/or other immunotherapy.

- Patients with prior radioimmunotherapy treatments (unless for retreatment under this
protocol).

- Patients receiving rituximab within 3 months, unless progressing after treatment.

- Patients with <50% LVEF by required MUGA or 2-D ECHO.

- Patients with <60% of predicted value by required pulmonary function tests.

- Patients who have active Hepatitis B or C or are known HIV positive.

- Patients with another primary malignancy (except basal/squamous cell carcinoma of the
skin or carcinoma in-situ of the cervix.

- Patients with other serious medical, surgical, or psychiatric history, unless
currently stable and well controlled, without significant increase in treatment
medications for at least 30 days preceding study entry.