Inclusion Criteria:

- Patients must have histologically confirmed diagnosis of diffuse large cell lymphoma

- Patients must be stage I or II (Modified Ann Arbor staging)

- Baseline measurements and evaluations must be obtained within 4 weeks of registration
to the study; abnormal PET scans will not constitute evaluable disease unless
verified by CT scan or other appropriate imaging; patients must have at least one
objective measurable disease parameter (a lesion with at least 1 dimension > 1.5 cm);
or if they are stage 1

- Stage I patients must have at least one of the following risk factors:

- Age >= 60 years

- Bulky disease (>= 5 cm in at least one dimension)

- Elevated LDH above institutional upper limit of normal

- ECOG performance status = 2

- Patients must not have had prior chemotherapy, radiation therapy, radioimmunotherapy,
or immunotherapy; a short course (=< 14 days prior to registration) of
corticosteroids is allowed

- ECOG performance status 0-2

- Absolute neutrophil count >= 1500/mm^3 (includes neutrophils and bands)

- Platelet count >= 100,000/mm^3

- Creatinine < 2.0 mg/dl

- Total bilirubin < 2 mg/dl (may be up to 3.0 mg/dl if due to liver involvement by
lymphoma); patients with elevated total bilirubin should have a direct bilirubin
checked; if the direct bilirubin is normal there is no need for a dose reduction

- Patients must have no evidence of other malignancy

- No prior chemotherapy or prior radiation therapy for other malignancies

- Not currently receiving hormone therapy or chemotherapy for another malignancy
even if the treatment is being provided in the adjuvant treatment setting, i.e.
with no evidence of the original other malignancy

- Adjuvant hormonal therapy must have been discontinued > 3 months before entering
this study

- Patients are eligible if they meet the following conditions: (a) treated
carcinoma-in-situ of the cervix; (b) treated squamous cell or basal cell skin
cancer; or (c) any other surgically cured malignancy from which the patient has
been disease free for at least 3 years

- Female patients must not be pregnant or breast feeding, as there would be radiation
exposure to the fetus or child; a negative pregnancy test is required =< 1 week prior
to registration for women of childbearing potential (WOCBP)

- Women of childbearing potential and sexually active males must be strongly advised to
use an accepted and effective method of contraception

- Patients must not have known CNS lymphoma, testicular lymphoma, or vitreous lymphoma

- Patients must have no known HIV infection. The safety of Zevalin™ in this population
has not been tested at this time

- Patients must not have a serious coexisting medical condition or active infection
which would compromise the ability to deliver standard R-CHOP chemotherapy

- Patients must have LV ejection fraction of > 45%

- No evidence of myelodysplasia on bone marrow aspiration and biopsy

- Patients must be tested for hepatitis B surface antigen within 2 weeks of
registration

- NOTE: Patients who test positive will be allowed to participate but must be
followed closely for clinical and laboratory signs of active HBV infection and
for signs of hepatitis