Lymphomas

Hodgkin’s and non-Hodgkin’s lymphomas are lymphoid neoplasms arising from B cells, T cells, or NK (natural killer) cells. [¹⁸F]FDG PET/CT is more accurate for the primary staging of lymphoma particularly because it can detect disease in normal sized lymph nodes, the liver, spleen and bone marrow. A major advantage of [¹⁸F]FDG PET in determining the outcome of therapy is distinguishing active lymphoma from fibrosis/necrosis in residual masses. Posttherapy [¹⁸F]FDG PET provides important prognostic information and has been incorporated into the currently used criteria for evaluating response to therapy in lymphoma (revised International Workshop Criteria—IWC). Interim [¹⁸F]FDG PET/CT also provides prognostic information and is being evaluated for “risk-adapted therapy” in setting of clinical trials. Radioimmunotherapy with the anti-CD20 monoclonal antibodies, 90 Y-ibritumomab and 131 I-tositumomab, is effective therapy for non-Hodgkin’s lymphoma. Currently, radioimmunotherapy is used in the relapsed/refractory setting and also for consolidation after front-line chemotherapy in low-grade follicular lymphoma. Optimal usage of radioimmunotherapy and additional indications are areas of ongoing active investigations.