Women with known or suspected recurrent or metastatic uterine cancer may be eligible for this study. Patients may participate in this study if they are at least 18 years of age, most participants will be receiving care at the clinical practices of the University of Pennsylvania.
\[18F\]fluoroestradiol (FES) PET/CT imaging will be used to evaluate estrogen receptor (ER) activity in areas of disease known by standard of care imaging (e.g. CT, MRI, Bone Scan, FDG PET/CT, ultrasound) or clinical exam. For patients starting a new line of therapy, imaging will occur prior to starting new therapy. For patients who completed an initial scan and are starting new therapy, some patients may also undergo a second FES PET/CT scan at the time of suspected progression of disease to compare for changes in FES uptake measures (prior to initiation of next line therapy). The selection of therapy will be made by a treating physician and will not be affected by participation in this imaging study. Results of the FES PET/CT scan may be shared with the treating physician or subject by request but will not be used to make clinical decisions about treatment.