Figure 2.

Transaxial fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET)-computed tomography (CT) images obtained from a 72-year-old male (patient 21) following external beam radiotherapy for prostate cancer. The patient’s series prostate-specific antigen (PSA) levels were unremarkable until two years later when the PSA level was 7.8 ng/ml. FDG PET-CT demonstrated an FDG-avid lesion in the left-side of the prostate (indicated by the arrows), which was confirmed as recurrent adenocarcinoma by transrectal biopsy.