Ability of contrast-enhanced ultrasonography to determine clinical responses of breast cancer to neoadjuvant chemotherapy

We aimed to determine whether contrast-enhanced ultrasonography can predict the effects of neoadjuvant chemotherapy on breast cancer. The clinical responses of 63 consecutive patients with breast cancer (T1-4, N0-1, M0) to neoadjuvant chemotherapy between October 2012 and May 2015 were assessed using contrast-enhanced magnetic resonance imaging, positron emission tomography/computed tomography and contrast-enhanced ultrasonography. Perfusion parameters for contrast-enhanced ultrasonography were created from time-intensity curves based on enhancement intensity and temporal changes to objectively evaluate contrast-enhanced ultrasonography findings. The sensitivity, specificity and accuracy of contrast-enhanced ultrasonography, magnetic resonance imaging and positron emission tomography/computed tomography to predict a pathological complete response were compared after confirming the pathological findings of surgical specimens. Twenty-three (36.5%) of the 63 patients achieved pathological complete response. The sensitivity, specificity and accuracy of contrast-enhanced ultrasonography for predicting pathological complete response were 95.7% (82.5-99.2%), 77.5% (69.9-79.5%) and 84.1% (74.5-86.7%). The sensitivity of contrast-enhanced ultrasonography was significantly greater than that of magnetic resonance imaging (95.7 vs. 69.6%, P = 0.047). The specificity and accuracy were significantly greater and tended to be greater, respectively, for contrast-enhanced ultrasonography than positron emission tomography/computed tomography (specificity, 77.5 vs. 52.5%, P = 0.02; accuracy, 84.1 vs. 69.8%, P = 0.057). Contrast-enhanced ultrasonography might serve as a new diagnostic modality when planning therapeutic strategies for patients with breast cancer after neoadjuvant chemotherapy.