Positron emission tomography and breast lesions: low FDG activity in early phase imaging is not essentially benign

Abstract

The frequency of malignancy with low FDG uptake is significant and often presents diagnostic challenges. The usefulness of dual-time point FDG-PET/CT imaging (including early "after 45 minutes" and delayed "after 100 minutes," phases after radionuclide administration) for detection of such tumors has been documented. The authors present 2 cases of pathologically proven breast cancer with minimally increased FDG uptake on the initial scan (maximum standardized uptake value; SUVmax <2.5). Detection was improved by performing a dynamic PET study with early and delayed scans. Patients with a poorly visualized breast lesion due to minimal FDG uptake on the initial FDG-PET images should not be considered as benign and deserves further delayed phase imaging.