OBJECTIVES: I. Assess two year progression free survival after treatment with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) plus rituximab followed by radiotherapy in patients with stage I, IE, or non-bulky stage II or IIE high risk localized intermediate or high grade non-Hodgkin's lymphoma. II. Determine the toxicity of this treatment in these patients.