<qa>  What is the name of the yttrium Y 90 ibritum- Determine the progression-free and overall survival of patients age 60 and over with previously untreated diffuse large B-cell lymphoma treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone R-CHOP combined with yttrium Y 90 ibritumomab tiuxetan. 