Conventional US combined with acoustic radiation force impulse (ARFI) elastography for prediction of triple-negative breast cancer and the risk of lymphatic metastasis.

PURPOSE: To evaluate the combination of conventional ultrasound (US) and acoustic radiation force impulse (ARFI) elastography in predicting triple-negative breast cancer and the likelihood of lymphatic metastasis. MATERIALS AND METHODS: A total of 178 women presenting from May 2013 to September 2015 with pathologically proven triple-negative (n = 60) or hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative breast cancer (n = 118) were reviewed. Conventional US and ARFI imaging including Virtual touch tissue image (VTI) and Virtual Touch tissue Quantification (VTQ), were performed for each breast nodule. Parameters collected included patient age, lymph node involvement, histological grade, tumor subtype, appearance on conventional US, shear wave velocity (SWV) value, VTI score and the boundary on VTI. The ARFI findings were compared with the pathological findings. RESULTS: Younger age (P < 0.001), higher histological grade (P < 0.001), lymphatic metastasis (P < 0.001), more nodes involved (P = 0.001), larger tumor size (P = 0.008), regular shape (P = 0.032), high VTI score (P = 0.006), unclear VTI boundary (P = 0.033), SWV >= 3.51 m/s (P = 0.015) were significantly associated with triple-negative breast cancer. High VTI score (P = 0.004) and a high SWV >= 4.15 m/s (P = 0.002) were significantly associated with lymphatic metastasis. CONCLUSION: Conventional US combined with ARFI may be used to predict triple-negative breast cancer. Those cancers with higher SWV and the high VTI score have a higher likelihood of lymphatic metastasis.