The Value of 18 Fluorine-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Imaging in Breast Cancer Staging

BACKGROUND: Accurate staging is important for management decisions in patients with newly diagnosed breast cancer. AIM: This study was conducted to evaluate the value of 18 fluorine-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) imaging in breast cancer staging.. METHODS: A prospective study of 80 patients (1 male and 79 female) mean age 51.13 years with histologically confirmed breast cancer. The staging procedures included history, physical examination, mammography, and CT of neck, chest, abdomen, and pelvis; then, PET/CT was performed in a time interval <30 days. The findings of PET/CT were compared with those of the other conventional methods. RESULTS: The agreement between conventional methods (mammography, breast ultrasound, contrast-enhanced CT of the neck, chest, abdomen, and pelvis) and 18F FDG-PET/CT was 0.6 for assessing the T stage, 0.39 for N stage, and 0.75 for M stage. There was moderate agreement between CT and 18F FDG-PET/CT in the detection of nodal lesions (K=0.6) and pulmonary lesions (K=0.51), while a perfect agreement was noted for detecting osseous (K=0.82) and liver lesions (K=0.81). In total, 50 patients (62.5%) were concordantly staged between the conventional imaging and 18F-FDG PET/CT, while 30 patients (37.5%) showed a different tumor, node, and metastasis stage. The changes were driven by the detection of additional findings (n=26) or exclusion of findings (n=4), mainly at the lymph nodes (LNs) and/or distant sites. Regarding N status, 18F FDG-PET/CT revealed previously unknown regional lymphatic spread in supraclavicular (n=4; 5%), infraclavicular (n=11; 13.7%), and internal mammary (n=12; 15%) lymph node groups. 18F-FDG PET/CT changed M status in a total of four patients (5%); three of them were upstaged by detecting distant metastases, while osseous deposits were excluded in one patient leading to downstaging. CONCLUSION: 18F-FDG-PET/CT is considered a valuable imaging tool in the initial staging of breast cancer, which significantly impacts the overall American Joint Committee on Cancer staging in 37.5% of our study population