The role of 18F-FDG PET/CT in the imaging of patients with breast cancer.

Diagnosis of the Primary Tumor In initial diagnosis, 18F-FDG PET/CT has questionable clinical value and, for this reason, is not used in routine practice to evaluate potential primary breast tumors. It has low sensitivity but high positive predictive value (PPV) (PPV 81%-100%). So, if increased uptake is found on 18F-FDG PET/CT in a breast lesion as an incidental finding, there is a high probability that it is due to malignancy. The sensitivity of 18F-FDG PET/CT depends on tumor size, histological type (invasive ductal carcinoma has a higher SUVmax than lobular carcinoma, and hormone receptor expression.