Breast imaging techniques are used to assess the
tumor response to
neoadjuvant treatment (
NAT), which is increasingly one of the preferred therapeutic options and increases the rate of breast conservation for
breast cancer. Herein, we report a case in which a woman was diagnosed with invasive
ductal carcinoma in the left breast and received
NAT before surgery. Automated breast ultrasound (AB US) was regularly performed before and during the
NAT to evaluate the
tumor response to
NAT by measuring diameter changes and volume reductions of the
tumor. Images showed that the
tumor size was significantly reduced and disappeared after 7 cycles of
NAT, except for macrocalcification. Postoperative histopathological examination confirmed that there were no
residual tumor cells. We found that AB US overcame the limitations of handheld US, such as operator dependence, poor reproducibility and limited field of view, and can be an alternative modality to assess the
tumor response of
NAT in the absence of magnetic resonance imaging (MRI) instruments.