Treatment recommendations for radioimmunotherapy in follicular lymphoma: a consensus conference report

Thomas E. Witzig*a, Paul Fishkinb, Leo I. Gordonc, Stephanie A. Gregoryd, Samuel Jacobse, Roger Macklisf, Peter Mclaughling, Oliver Pressh & Andrew D. Zelenetzia Mayo Clinic, Rochester, MN, USAb Illinois Cancer Care, Peoria, IL, USAc Northwestern University Feinberg School of Medicine, Chicago, IL, USAd Rush University Medical Center, Chicago, IL, USAe University of Pittsburgh Medical Center, Pittsburgh, PA, USAf Cleveland Clinic, Cleveland, OH, USAg M. D. Anderson Cancer Center, Houston, TX, USAh Fred Hutchinson Cancer Research Center, Seattle, WA, USAi Memorial Sloan-Kettering Cancer Center, New York, NY, USACorrespondence: Thomas E. Witzig, MD, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA. Tel: 507-284-0527. E-mail: witzig.thomas@mayo.eduRadioimmunotherapy (RIT) with 90Y-ibritumomab tiuxetan or 131I-tositumomab combines a radiation-emitting radionuclide with an antibody targeting CD20 to treat B-cell non-Hodgkin lymphoma. Multiple studies demonstrate favorable RIT efficacy and safety profiles in follicular lymphoma (FL). The primary toxicity is reversible myelosuppression. Various FL treatment options include single-agent immunotherapy, radiation, chemoimmunotherapy, and RIT. Examining RIT clinical effects and position within treatment algorithms is important to optimal patient benefit. Clinical studies support using single-agent RIT in relapsed/refractory FL, in selected patients with new, untreated FL, and as consolidation after induction chemotherapy or chemoimmunotherapy. RIT as consolidation enhances response rates (with conversion of partial to complete responses following induction therapy) and prolongs disease control versus observation. The overall response rate is 60–80% in the relapsed setting. Time to progression is longer with low-bulk disease, fewer prior therapies, and retained rituximab sensitivity. RIT apparently does not preclude subsequent therapies or increase risk of secondary malignancies compared with chemotherapy's known risk. This article summarizes consensus recommendations for RIT and presents RIT treatment algorithms developed by hematologists/oncologists who regularly treat patients with FL. Maximizing RIT benefit requires healthcare providers to utilize algorithms assisting with treatment decisions.