RATIONALE: Radiolabeled monoclonal antibodies, such as iodine I 131 tositumomab, can locate cancer cells and deliver radioactive cancer-killing substances to them without harming normal cells. Combining a radiolabeled monoclonal antibody with autologous stem cell transplantation may be an effective treatment for non-Hodgkin's lymphoma.

PURPOSE: Phase II trial to study the effectiveness of combining iodine I 131 tositumomab with autologous stem cell transplantation in treating older patients who have relapsed or refractory non-Hodgkin's lymphoma.

OBJECTIVES:

Primary

• Determine the progression-free survival of older patients with relapsed or refractory non-Hodgkin's lymphoma treated with iodine I 131 tositumomab followed by autologous stem cell transplantation.

Secondary

• Determine the overall survival of patients treated with this regimen.
• Determine the toxicity and tolerability of this regimen in these patients.

OUTLINE:

• Radioimmunotherapy: Patients receive a test dose of iodine I 131 tositumomab on day -24 to determine biodistribution. Patients then receive therapeutic iodine I 131 tositumomab IV over 1 hour on day -14 and are entered into radiation isolation until day -4.
• Autologous stem cell transplantation: Patients undergo autologous bone marrow or peripheral blood stem cell transplantation on day 0. Patients undergoing bone marrow transplantation receive filgrastim (G-CSF) or sargramostim (GM-CSF) subcutaneously beginning on day 0 and continuing until blood counts recover.

Patients are followed at 1, 3, 6, and 12 months and then annually thereafter.

PROJECTED ACCRUAL: A total of 24-30 patients will be accrued for this study within 2 years.

DISEASE CHARACTERISTICS:

• Histologically confirmed non-Hodgkin's lymphoma

• CD20+ disease

• Failed at least 1 prior standard systemic therapy

• Persistent lymphoma by physical examination, radiographic studies, bone marrow evaluations, flow cytometry, or polymerase chain reaction

• Tumor burden less than 500 cc by computed tomography or MRI

  • No splenomegaly

• Autologous hematopoietic stem cells or bone marrow harvested and cryopreserved

  • No circulating lymphoma cells by morphology or flow cytometry at or near the time of peripheral blood stem cell (PBSC) collection if unpurged PBSCs are to be used
  • 10% or less marrow involvement by flow cytometry or morphology if purged bone marrow is to be used

• No CNS lymphoma

• No chronic lymphocytic leukemia or small lymphocytic lymphoma/well-differentiated lymphocytic lymphoma

PATIENT CHARACTERISTICS:

Age

• 60 to 80

Performance status

• SWOG 0-1

Life expectancy

• More than 60 days

Hematopoietic

• See Disease Characteristics

Hepatic

• Bilirubin less than 1.5 mg/dL

Renal

• Creatinine less than 2.0 mg/dL

Cardiovascular

• No active coronary artery disease

Pulmonary

• FEV_1 at least 70% of expected
• Vital capacity at least 70% of expected

Other

• Not pregnant
• Negative pregnancy test
• Fertile patients must use effective contraception
• HIV negative
• Able to perform self-care during radiation isolation
• No major organ dysfunction
• No major infection
• No circulating anti-mouse antibody
• No other serious medical condition considered to represent contraindications to bone marrow transplantation
• No competing causes of death that would predict life span to be less than 10 additional years

PRIOR CONCURRENT THERAPY:

Biologic therapy

• No prior bone marrow or stem cell transplantation

Chemotherapy

• Not specified

Endocrine therapy

• Not specified

Radiotherapy

• No prior radiotherapy greater than 20 Gy to any critical normal organ (e.g., lung, liver, spinal cord, or more than 25% of red marrow)

Surgery

• Not specified

Other

• More than 30 days since prior systemic antilymphoma therapy