The links after "Participants" show which Southwest Oncology Group institutions are eligible to participate in this study.

The orange "Where is This Study Open?" tab at the bottom of the page shows the institutions whose Institutional Review Boards (IRBs) have approved the protocol so that it can be opened at that institution. Clicking on the Institution Name will show the points of contact for information about this study at that institution.

Disease Committee: Lymphoma

Participants: Members, CCOP, Affiliates, Medical Oncologists, Pathologists

Eligibility Criteria: Previously untreated Stage III, IV, or bulky Stage II diffuse large B-cell NHL, which is positive for CD20; registering institution must have submitted the S0433 site contact information form and a copy of their radioactive materials license to GlaxoSmithKline and been approved by GlaxoSmithKline for this study; specimens must be available for pathology review (H&E section, paraffin block, or at least 12 unstained slides from the original diagnostic specimen); >= age 18; PS=0-2; must have bidimensionally measurable disease; must have unilateral or bilateral bone marrow aspirate and biopsy performed w/in 42 days prior to registration; must have a CT scan of the chest/abdomen and pelvis performed w/in 28 days prior to registration; must not have clinical evidence of CNS involvement by lymphoma; must not have a previous diagnosis of indolent lymphoma (histologic transformation are not eligible); must not have received prior chemotherapy, radiation, or antibody therapy for lymphoma; serum LDH must be measured w/in 28 days prior to registration; must have < 20,000 lymphoid cells/mcL w/in 28 days prior to registration; must have a cardiac ejection fraction >= 45% by MUGA scan or an ECHO w/ no significant abnormalities w/in 42 days prior to registration; must not be HIV+ or have a history of solid organ transplantation; must not be requiring continuous supplemental oxygen therapy; no prior malignancy except basal or squamous cell skin cancer, in situ cervical cancer, adequately treated Stage I or II cancer for which the patient is currently in complete remission, or any other cancer for which the patient has been disease-free for >= 5 years; patients of reproductive potential must agree to use an effective contraceptive method from the time of registration to 6 months after receiving the Iodine-131 anti-B1 tositumomab antibody.