Description:

The purpose of this study to compare two types of cancer imaging scans to see which is better at detecting and monitoring metastatic ILC. This study will compare PET/CT (positron emission tomography/computed tomography) scans using the radiotracer fluorine 18 (18F)-fluoroestradiol (FES) with a standard imaging approach for detecting and monitoring ILC, PET/CT scans using the radiotracer 18F-fluorodeoxyglucose (FDG). These scans will be referred to as FES PET/CT scans and FDG PET/CT scans.