Future directions in radioimmunotherapy for B-cell lymphoma.

Rituximab has become a staple in the management of B-cell non-Hodgkin's lymphoma, but it has limited activity as a single agent, with responses in about half of patients with recurrent follicular and low-grade lymphoma. Radioimmunotherapy (RIT) may surmount inherent or acquired antibody resistance by targeting a radionuclide to tumor cells. This strategy is particularly appealing for B-cell lymphoma because CD20 affords an outstanding target and lymphomas are inherently radiosensitive. The efficacy and safety of RIT have been established in the treatment of relapsed or refractory indolent non-Hodgkin's lymphoma, and yttrium 90 ibritumomab tiuxetan (Zevalin; Biogen Idec Inc, Cambridge, MA) was the first RIT agent to be approved by the US Food and Drug Administration. This supplement to Seminars in Oncology seeks to present hematologists and medical oncologists with the most recent developments in RIT with (90)Y ibritumomab tiuxetan for non-Hodgkin's lymphoma, to clarify the role of the medical oncologist in the administration of the ibritumomab tiuxetan regimen, to indicate how and when RIT with (90)Y ibritumomab tiuxetan may most successfully be integrated into the continuum of treatment for patients with B-cell lymphoma, and to describe ongoing clinical trials with (90)Y ibritumomab tiuxetan in B-cell lymphomas.