PET Scans in the Staging of Lymphoma: Current Status

Abstract

Abstract Learning Objectives After completing this course, the reader will be able to: Define the role of diagnostic PET in the staging of patients with lymphoma. Discuss the role of PET in the evaluation of residual masses in patients with lymphoma. Explain the limitations of PET scanning and the special situations where PET scanning has been used in the evaluation of patients with lymphoma. Access and take the CME test online and receive one hour of AMA PRA category 1 credit at CME.TheOncologist.com Positron emission tomography (PET) is a novel functional imaging technique that provides several inherent advantages over conventional nuclear scintigraphy. Several studies have suggested a role for PET using the positron emitter fluorine-18 in the diagnosis and follow-up of patients with lymphoma. This review summarizes the existing data evaluating the role of 2-fluoro-2-deoxy-D-glucose (FDG)-PET in both the staging and follow-up of patients with lymphoma. Most studies of PET involve patients with either Hodgkin's disease or diffuse large B-cell non-Hodgkin's lymphoma. PET detects more disease sites above and below the diaphragm on staging of lymphoma than gallium scintigraphy and may have particular utility in the evaluation of the spleen. Moreover, persistently positive PET scans during and after chemotherapy appear to have a high sensitivity for predicting subsequent relapse. A negative PET scan at the end of therapy provides very favorable prognostic information. Persistently positive PET scans at the end of therapy warrant close follow-up or additional diagnostic procedures, since some of those patients may remain in prolonged remission. Clearly, additional studies, including prospective blinded trials and cost-effectiveness analyses, are warranted to determine which subsets of patients with lymphoma ultimately will benefit from this modality.