Focal Hepatic Fluorodeoxyglucose Uptake Mimics Liver Metastasis Following External Beam Radiation for Gastroesophageal Cancers: A Case and Review of the Literature

Patients with locally advanced gastroesophageal cancers frequently undergo concurrent chemotherapy and radiation (CRT). 18-fluorodeoxyglucose-positron emission tomography ( 18 FDG-PET) in combination with computed tomography is used for disease staging and assessing response to therapy. 18 FDG-PET interpretation is subject to confounding influences including infectious/inflammatory conditions, serum glucose, and concurrent medications. Radiotherapy induces tissue damage, which may be associated with FDG-avidity; however, few reports have described the focal areas of hepatic uptake following concurrent chemoradiation (CRT). Distinguishing hepatic FDG uptake from disease progression represents an important clinical scenario. Here, we present two cases of unexpected FDG uptake in the liver after CRT and review the literature describing incidental liver uptake on FDG-PET.