Value of [18F]Fluorodeoxyglucose–Positron Emission Tomography in Managing Adults with Aggressive Non-Hodgkin's Lymphoma

An increased glucose metabolic rate is observed with various degrees of intensity in different subtypes of aggressive lymphomas. [18F]Fluorodeoxyglucose (FDG)–positron emission tomography (PET; FDG-PET) allows functional imaging of this phenomenon through 3-dimensional tomographic slices, which are now easily fused with computed tomography (CT) images. [18F]Fluorodeoxyglucose–positron emission tomography staging appears superior to conventional staging modalities for detecting nodal and extranodal lymphoma. When performed after first-line chemotherapy, FDG-PET is more efficient than CT and conventional diagnostic methods to predict the disease outcome. Some studies have reported that the relapse rate is 100% in patients with positive PET findings after treatment and 17% in patients with negative PET findings. This imaging modality can also assess early response after 1-2 cycles of chemotherapy, thus identifying responders from patients whose cancer will fail to respond to first-line therapy or will relapse shortly after having exhibited a partial or complete remission. [18F]Fluorodeoxyglucose–PET also seems useful for an accurate selection of patients who will benefit from highly intensive treatment.