Can computed tomography predict nodal metastasis in breast cancer patients?

Background: Axillary lymph node metastasis is considered one of the main prognostic factors clinically used for the evaluation of breast cancer patient. Also, an accurate diagnosis of axillary lymph node metastasis has a significant effect on the tumor staging and treatment planning. Ultrasonography is a noninvasive, available imaging modality that is capable of giving a real-time evaluation of axillary lymph nodes in breast cancer cases. On the other hand, multi-detector-row computed tomography is increasingly preferred by clinicians to preoperatively evaluate regional lymph node status in many cancers. The aim of this study was to compare the diagnostic performance of computed tomography against ultrasound in detecting axillary lymph node status in breast cancer patients. Results: One hundred and fifty breast cancer patients were included in this prospective study. According to the final pathological results, 79/150 (52.7%) lymph nodes were metastatic, while 71/150 (47.3%) lymph nodes were benign with no evidence of metastases. Ultrasound examination has achieved a sensitivity of 76.4% and a specificity of 60.8% with overall diagnostic accuracy of 68.7%. Computed tomography (CT) examination has achieved a much higher sensitivity of 98.6%, a much lower specificity of 35.4%, and overall diagnostic accuracy of 65.3%. In our study, CT examination was superior on ultrasound in the determination of the level of lymph node affection, and this may be attributed to the dependency of ultrasound examination on the operator's experience. Conclusions: CT is not routinely used in the assessment of nodal stage. However, if used in proper clinical setting, it may increase our confidence in excluding nodal metastasis owing to its high sensitivity. Despite its low specificity, it may act as road map for the surgeon, providing the ability to assess all groups of lymph nodes as well as the number of the suspicious lymph nodes.