S0313 Cyclophosphamide, Doxorubicin, Vincristine, Prednisone, and Radiation Therapy Followed By Rituximab and Yttrium Y 90 Ibritumomab Tiuxetan in Treating Patients With Stage I or Stage II Non-Hodgkin's Lymphoma

DISEASE CHARACTERISTICS: * Histologically confirmed aggressive non-Hodgkin's lymphoma of 1 of the following subtypes: * Diffuse large B-cell * Mantle cell * High-grade B-cell, Burkitt's, or Burkitt-like * Anaplastic large cell (B-cell phenotype only) * Stage I, IE, or non-bulky\* stage II or IIE disease by Ann Arbor classification * Patients who have bulky stage II or IIE disease are ineligible even if, after resection, the measurements are less than 10.0 cm NOTE: \*Non-bulky disease defined as any tumor measuring less than 10.0 cm or occupying less than 1/3 of the chest diameter * CD20-expressing disease by flow cytometry or immunoperoxidase staining * Aggressive lymphomas must have at least 1 of the following adverse prognostic factors: * Non-bulky stage II or IIE disease * At least 60 years of age * Zubrod performance status of 2 * Lactic dehydrogenase greater than upper limit of normal * All disease must be encompassable in a single radiation port (including any site of resected disease) NOTE: A new classification scheme for adult non-Hodgkin's lymphoma has been adopted by PDQ. The terminology of "indolent" or "aggressive" lymphoma will replace the former terminology of "low", "intermediate", or "high" grade lymphoma. However, this protocol uses the former terminology. PATIENT CHARACTERISTICS: Age * Over 18 Performance status * Zubrod 0-2 Life expectancy * Not specified Hematopoietic * Not specified Hepatic * Not specified Renal * Not sp…