The proposed clinical trial will be an imaging, open label, non-randomized, single site pilot study in patients with locally advanced or metastatic pancreatic carcinoma who will be treated with gemcitabine or other nucleoside analogs. Study participants will receive an IV injection of 2.59 MBq/kg ± 10% of \[18\]F-FLT (range: 100 to 350 MBq). If clinically indicated, dynamic PET scan imaging may start immediately before the injection, followed by half-body or limited frame scanning, using either a PET/CT or PET scanner. The first \[18\]F-FLT PET scan for each subject will occur within 4 weeks prior to commencement of his/her treatment. Study subjects will have a follow-up \[18\]F-FLT-PET scan at the time of disease progression, to a maximum of two \[18\]F-FLT PET scans. The same imaging procedure will be followed for both \[18\]F-FLT PET scans. At the same time as the \[18\]F-FLT PET scans occur, the patients' index tumour lesions will be re-evaluated by the same imaging modality originally used to assess the index lesions. Images will be interpreted by an experienced Nuclear Medicine physician with regard to normal physiological uptake of \[18\]F-FLT (RUS, SUV, and T/B). The location and relative uptake of normal and abnormal \[18\]F-FLT biodistribution patterns will be noted and correlated with time to disease progression and hENT1 expression in biopsy samples, where available. A medical chart review will be done at regular intervals to assess response to treatment, time to disease progression, and overall survival. Disease progression will be determined using the National Cancer Institute's Response Evaluation Criteria In Solid Tumours (RECIST).
