Diagnostic performance of preoperative 18F-FDG PET/CT in detecting axillary lymph node metastasis in breast cancer

Objective: To evaluate the diagnostic performance of axillary lymph node SUVmax measured on preoperative 18F-FDG PET/CT in predicting pathological axillary metastasis and to investigate clinicopathological and imaging factors associated with axillary involvement in breast cancer. Methods: This single-center retrospective study included 62 selected patients who underwent clinically indicated preoperative PET/CT between 2021 and 2025 and had postoperative axillary pathological evaluation. Histopathology was accepted as the reference standard. Demographic, clinical, and imaging variables were analyzed. The optimal SUVmax cut-off was determined using ROC analysis, and variables associated with axillary metastasis were explored using multivariable logistic regression.Results: Pathological axillary metastasis was detected in 34 patients (54.8%). Advanced T stage was significantly associated with metastasis (p=0.009). Axillary lymph node short-axis diameter and SUVmax were significantly higher in the metastasis-positive group (p