*NOTE: Patients receive indium In 111 ibritumomab tiuxetan IV over 10 minutes on days 1 and 8. Patients undergo whole-body gamma camera imaging, single-photon emission computed tomography/CT scans, and blood sampling after each dose of indium In 111 ibritumomab tiuxetan to determine biodistribution. If biodistribution is acceptable, patients receive yttrium Y 90 ibritumomab tiuxetan.