Inclusion Criteria

DISEASE CHARACTERISTICS:

- Diagnosis of diffuse large B-cell lymphoma, meeting 1 of the following criteria:

- Failed to achieve at least partial remission

- Failed to respond to prior primary therapy or salvage chemotherapy

- Disease progression within 6 weeks after achieving remission

- CD20 expression at diagnosis or relapse

- No more than 4 prior regimens using chemotherapy, radiotherapy, or immunotherapy

- The addition of radiotherapy or a monoclonal antibody to chemotherapy is
considered 1 treatment regimen provided the addition was part of the initial
treatment plan

- The addition of these therapies due to lack of response or poor response is
considered an additional treatment regimen whether given in the front line
or salvage setting

PATIENT CHARACTERISTICS:

Performance status

- ECOG 0-1

Life expectancy

- Not specified

Hematopoietic

- Absolute neutrophil count ≥ 1,000/mm^3

- Platelet count ≥ 100,000/mm^3

Hepatic

- Direct bilirubin ≤ 2 mg/dL

- AST or ALT < 3 times upper limit of normal

Renal

- Creatinine ≤ 2.0 mg/dL

Cardiovascular

- Ejection fraction ≥ 40%

Pulmonary

- DLCO ≥ 60% of predicted

Other

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- No other malignancy within the past 2 years except curatively treated basal cell or
squamous cell skin cancer or carcinoma in situ of the cervix

- No active infection requiring oral or IV antibiotics

- HIV negative

PRIOR CONCURRENT THERAPY:

Biologic therapy

- See Disease Characteristics

- See Radiotherapy

Chemotherapy

- See Disease Characteristics

Radiotherapy

- See Disease Characteristics

- No prior radioimmunotherapy