Current clinical status of 18F-FLT PET or PET/CT in digestive and abdominal organ oncology.

Positron emission tomography (PET) or PET/computed tomography (CT) using 18F-3'-fluoro-3'-deoxythymidine (18F-FLT) offers noninvasive assessment of cell proliferation in human cancers in vivo. The present review discusses the current status on clinical applications of 18F-FLT-PET (or PET/CT) in digestive and abdominal oncology by comparing with 18F-fluorodeoxyglucose (18F-FDG)-PET (or PET/CT). The results of this review show that although 18F-FLT uptake is lower in most cases of digestive and abdominal malignancies compared with 18F-FDG uptake, 18F-FLT-PET can be used to detect primary tumors. 18F-FLT-PET has shown greater specificity for N staging than 18F-FDG-PET which can show false-positive uptake in areas of inflammation. However, because of the high background uptake in the liver and bone marrow, it has a limited role of assessing liver and bone metastases. Instead, 18F-FLT-PET will be a powerful tool for monitoring response to treatment and provide prognostic information in digestive and abdominal oncology.