Prostate Cancer Liver Metastases Presenting as Relatively Photopenic Lesions on 18F-Fluciclovine PET/CT.

A 66-year-old man with prostate adenocarcinoma status post radical retropubic prostatectomy and bilateral pelvic lymph node dissection, followed by salvage external beam radiation therapy to the prostate bed 1 year after surgery. Over the course of 17 years, the patient underwent multiple lines of systemic treatment for recurrent disease. He was referred for restaging 18F-fluciclovine PET/CT due to rising serum prostate-specific antigen levels. Contrast-enhanced 18F-fluciclovine PET/CT images demonstrated multiple new liver metastases, which were relatively photopenic in comparison with the physiologic radiotracer activity in the surrounding normal liver parenchyma.