Dual-Time 18F-FDG PET/CT Imaging in Initial Locoregional Staging of Breast Carcinoma: Comparison with Conventional Imaging and Pathological Prognostic Factors.

The aims of this retrospective study were to consider the diagnostic role of dual-time 18F-fluorodeoxyglucose positron emission tomography and computed tomography (18F-FDG PET/CT) in detection of breast carcinoma and axillary lymph node (ALN) status and to evaluate the primary tumor 18F-FDG uptake pattern. Preoperative staging was performed by 18F-FDG PET/CT in 78 female patients with breast carcinoma. Conventional imaging results were evaluated by breast magnetic resonance imaging (MRI) of 79 lesions in 78 patients, bilateral mammography (MMG) of 40 lesions in 40 patients, and breast ultrasonography (USG) of 47 lesions in 46 patients. The primary tumor detection rate using 18F-FDG PET/CT was higher than those using MRI, USG, and MMG. The sensitivity and specificity of 18F-FDG PET/CT scans for detecting multifocality were higher than those of MRI. The specificity of ALN metastasis detection with MRI was higher than that with 18F-FDG PET/CT, but 18F-FDG PET/CT had higher sensitivity. Higher 18F-FDG uptake levels were detected in patients with ALN metastasis, histologic grade 3, estrogen-progesterone-negative receptor status, lymphatic invasion, and moderate to poor prognostic groups. There was no statistical difference for the retention index in categorical pathological parameters except for progesterone-negative status. In conclusion, 18F-FDG PET/CT scans may be a valuable imaging technique for evaluating primary tumor and axillary status in staging breast carcinoma and 18F-FDG uptake may be a prognostic factor that indicates aggressive tumor biology and poor prognosis. Dual-time imaging in breast carcinoma staging may not be used for predicting pathological criteria and the aggressiveness of primary lesions.