FDG PET and FES PET Predict PFS on Endocrine Therapy—Letter

With great interest, we read the article by Kurland and colleagues ([1][1]) that investigates the value of 18F-fluoroestradiol (FES) and 18F-fluorodeoxyglucose (FDG) PET for the prediction of progression-free survival (PFS) in 84 patients with advanced, estrogen receptor (ER)–positive breast