Initial Staging of Lymphoma With Positron Emission Tomography and Computed Tomography

Lymphomas represent a diverse range of diseases with manifold presentations, outlook, and therapeutic approaches. Key to the modern management of lymphoma is accurate delineation of the extent of disease. The inability of computed tomography (CT) to identify the involvement of nonenlarged nodes and its relatively poor sensitivity in the detection of extra-nodal sites of involvement limit the performance of noninvasive staging techniques. Functional imaging techniques such as Ga-67 scintigraphy have been used for many years to improve the evaluation of patients with lymphoma. While providing complementary information to CT in many clinical settings, functional imaging has never had sufficient accuracy or localizing ability to seriously challenge conventional primary staging paradigms. ¹⁸F-Fluorodeoxyglucose positron emission tomography (FDG PET), however, has been demonstrated to have both higher sensitivity and specificity than CT in many comparative series. Now that this technology also can be performed at the same time as structural imaging in the form of hybrid PET/CT devices, clinicians are rethinking the methods used to select, plan, and monitor therapy of lymphoma patients. In our institution, FDG PET/CT has become the preferred initial staging tool for patients with lymphoma.