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

Normalization of Liver Physiological Uptake as a Response Marker to Treatment in Prostate Cancer Liver Metastases Appearing as Photopenic on Baseline 18F-Fluorocholine PET/CT

ABSTRACT

In a 54-year-old patient referred for 18F-fluorocholine (FCH) baseline PET/CT before chemotherapy for biopsy-proven liver metastases, FCH PET/CT demonstrated multiple hypodense hepatic lesions with no FCH uptake and 2 positive bone metastases. FCH PET/CT performed after 6 cycles of docetaxel demonstrated a near normalization of the physiological uptake in the area of the sterilized liver metastases, which was confirmed by a drop in prostate-specific antigen and a complete metabolic response in the bone metastases. The present case demonstrates a new pattern of response defined by a reverse phenomenon from photopenic to normal uptake in responding liver metastases.

Incidental Serous Cystadenoma Presenting as a Photopenic Pancreatic Defect on 18F-Fluciclovine PET/CT

ABSTRACT

18F-fluciclovine (Axumin) PET/CT has been widely used for the evaluation of biochemically recurrent prostate cancer following prior treatment. While lymph node and visceral organ metastases typically show increased radiotracer uptake, altered patterns of normal physiologic activity may also provide insight into other disease processes. We present a case of an incidental pancreatic head mass presenting as a photopenic defect on a staging 18F-fluciclovine PET/CT, which was subsequently confirmed to be a benign serous cystadenoma using multisequence MRI.