A Rare Case of Radiation-Induced Liver Disease in Treated Abdominal Lymphoma Showing High [¹⁸F]FDG Avidity and Low EOB Uptake Proportional to the Irradiation Dose

A 44-year-old woman presented with high [18F]FDG uptake liver lesion after six courses of R-CHOP and radiotherapy for abdominal DLBCL, which was misdiagnosed as a hepatic invasion. EOB–MRI showed slight T2 hyperintensity, low-intensity DWI, and decreased EOB uptake in the hepatocellular phase. Compared with the pretreatment planning CT, the liver lesion coincided with the area of >40.5 Gy, resulting in the diagnosis of RILD. At the follow-up [18F]FDG PET/CT 7 months after irradiation, the abnormal liver uptake disappeared. Comparing [18F]FDG PET/CT, EOB–MRI, and planning CT can lead to the correct diagnosis of RILD and avoid unnecessary biopsies and treatment changes.