Liver Abscess With High 18F-FDG Uptake and No 18F-Fluorothymidine Uptake

18F-FDG accumulates not only in malignant lesions but also in infectious and inflammatory ones. 3'-deoxy-3'-18F-fluorothymidine (FLT) has been investigated as a promising PET tracer for evaluating tumor proliferating activity. We report a case of liver abscess during therapy of pancreatic cancer that underwent FDG PET/CT and FLT PET/CT studies. Although FDG PET/CT demonstrated several regions of increased uptake in the liver, FLT PET/CT showed no increased uptake in the liver.