Radioimmunotherapy for non-Hodgkin's lymphoma: a review for radiation oncologists

PURPOSE: The aim of this study was to review advances in radioimmunotherapy (RIT) for non-Hodgkin's lymphoma (NHL) and to discuss the role of the radiation oncologist in administering this important new form of biologically targeted radiotherapy. METHODS AND MATERIALS: A review of articles and abstracts on the clinical efficacy, safety, and radiation safety of yttrium Y 90 (90Y) ibritumomab tiuxetan (Zevalin) and iodine I 131 tositumomab (Bexxar) was performed. RESULTS: The clinical efficacy of RIT in NHL has been shown in numerous clinical trials of 90Y ibritumomab tiuxetan and 131I tositumomab. Both agents have produced significant responses in patients with low-grade, follicular, or transformed NHL, including patients with disease that had not responded or had responded poorly to previous chemotherapy or immunotherapy. Reversible toxicities such as neutropenia, thrombocytopenia, and anemia are the most common adverse events with both agents. CONCLUSIONS: Radioimmunotherapy is safe and effective in many patients with B-cell NHL. 90Y ibritumomab tiuxetan and 131I tositumomab can produce clinically meaningful and durable responses even in patients in whom chemotherapy has failed. Treatment with RIT requires a multispecialty approach and close communication between the radiation oncologist and other members of the treatment team. The radiation oncologist plays an important role in treating patients with RIT and monitoring them for responses and adverse events after treatment.