Agreement and Diagnostic Accuracy of Ultrasonography versus Computed Tomography in Detecting Axillary and Extra‐Axillary Lymphadenopathy in Metastatic Breast Cancer

ABSTRACT Purpose This study aimed to compare the performance of ultrasonography (US) and computed tomography (CT) in identifying axillary and extra‐axillary lymphadenopathy in patients with metastatic breast cancer (BC). Methods This cross‐sectional study included 40 patients who underwent US and CT for nodal staging as part of their diagnostic workup. CT served as the reference standard to calculate sensitivity, specificity, positive and negative predictive value (PPV/NPV), and accuracy. Results US demonstrated very good diagnostic performance at the axillary level I (sensitivity, specificity, PPV, NPV, and accuracy = 1.00). However, sensitivity declined at axillary levels II (0.67) and III (0.57), and further in extra‐axillary regions, though specificity and PPV remained high across all regions (≥ 0.89). CT identified more yet statistically insignificant positive nodes in the deeper axillary and extra‐axillary regions. Correlation in lymph node counts was very high at axillary level I, moderate at level II, and fair at level III (intraclass correlation coefficient = 0.91, 0.78, and 0.55, respectively). Conclusion US is reliable for superficial axillary level staging, but may underestimate deeper axillary or extra‐axillary regions. While US alone may be sufficient in patients who require only initial axillary assessment, CT should be considered when comprehensive staging across is required.