Patients With Low-Grade Non-Hodgkin's Lymphoma Previously Treated With Iodine I 131 Tositumomab

This is a multi-center study for the long-term follow-up of surviving patients who are expected to complete or who have completed at least two years of follow-up after treatment with Iodine I 131 Tositumomab (BEXXAR) on Studies CP-97-011, CP-98-025, CP-99-032, or CP-99-036. All patients will be assessed for survival and disease status, including subsequent therapy for NHL, and for long-term safety. Additionally Laboratory evaluations consisting of a TSH level and a complete blood cell (CBC) count with a differential and platelet count will be obtained annually. Additionally, patients who remain in long-term response following Iodine I 131 Tositumomab treatment will be followed for response and progression.