Evaluation of axillary status in patients with breast cancer using thin-section CT

Background. In recent years, the surgical management of patients with breast cancer has shifted to a locoregional approach, and evaluating the patient's axillary lymph node status is of the greatest importance in determining the appropriate treatment strategy. We evaluated on the efficacy of preoperative axillary staging using contrast-enhanced computed tomography (CE-CT). Methods. Between 2000 and 2003, 235 patients with operable breast cancer who underwent CE-CT before surgery and 137 patients who received neoadjuvant chemotherapy (NAC) and underwent CE-CT before NAC and surgery were enrolled in this study. The axillary status was evaluated based on three criteria (short-axis diameter, shape, and enhancement type), and the diagnosis was correlated with the histopathological results. Results. In patients who did not receive NAC, the size criterion of a short-axis diameter of more than 5 mm provided a sensitivity of 78%, a specificity of 75%, and an accuracy of 76% in predicting node-positive status. According to the size criterion of a short-axis diameter of more than 5 mm and the shape criterion of the absence of intranodal fat density, the specificity and accuracy were 90% and 81%, respectively, and according to the enhancement type criterion of early enhancement, the corresponding values were 89% and 78%. Evaluation was more difficult in patients who received NAC and the sensitivity of the size-based criterion in the patients who received NAC was lower than in those who did not. Conclusion. These findings suggest that CE-CT based on size criteria is useful for evaluating the preoperative axillary status of breast cancer patients, but that evaluation is more difficult and the sensitivity is reduced in patients who have received NAC.