Assessment of the axilla before and after NAC with US can help guide surgical management. US permits routine visualization of stage I and II nodes. By identifying subclinical metastases in clinically node-negative patients, US-guided fine-needle aspiration (FNA) or core needle biopsy (CNB) may select patients who require axillary lymph node dissection [116]. However, a study of 402 patients with a clinically negative axilla demonstrated that half of patients with abnormal lymph nodes on pretreatment imaging did not require axillary lymph node dissection [116]. Therefore, pretreatment imaging of the axilla in clinically node-negative patients remains controversial [4]. US-Guided Core Biopsy Axillary Node There is no evidence to support US-guided sampling as the initial imaging test for axillary lymph node evaluation. However, US-guided axillary lymph node sampling is typically the next study performed when axillary imaging is suspicious for metastatic disease. Overall, US-guided biopsy offers a minimally invasive option to obtain histopathologic proof of axillary nodal involvement for suspicious findings, although a negative biopsy does not reliably exclude metastatic disease, and therefore surgical pathology remains the reference standard. When US- guided biopsy confirms metastatic disease in pathologic-appearing nodes, it can obviate the need for pretreatment sentinel node biopsy, because the completion of axillary surgery is typically performed after therapy [2,117]. US-Guided Fine Needle Aspiration Biopsy Axillary Node There is no evidence to support US-guided sampling as the initial imaging test for axillary lymph node evaluation. However, US-guided axillary lymph node sampling is typically the next study performed when axillary imaging is suspicious for metastatic disease.
Monitoring Response to Neoadjuvant Systemic Therapy for Breast Cancer. Assessment of the axilla before and after NAC with US can help guide surgical management. US permits routine visualization of stage I and II nodes. By identifying subclinical metastases in clinically node-negative patients, US-guided fine-needle aspiration (FNA) or core needle biopsy (CNB) may select patients who require axillary lymph node dissection [116]. However, a study of 402 patients with a clinically negative axilla demonstrated that half of patients with abnormal lymph nodes on pretreatment imaging did not require axillary lymph node dissection [116]. Therefore, pretreatment imaging of the axilla in clinically node-negative patients remains controversial [4]. US-Guided Core Biopsy Axillary Node There is no evidence to support US-guided sampling as the initial imaging test for axillary lymph node evaluation. However, US-guided axillary lymph node sampling is typically the next study performed when axillary imaging is suspicious for metastatic disease. Overall, US-guided biopsy offers a minimally invasive option to obtain histopathologic proof of axillary nodal involvement for suspicious findings, although a negative biopsy does not reliably exclude metastatic disease, and therefore surgical pathology remains the reference standard. When US- guided biopsy confirms metastatic disease in pathologic-appearing nodes, it can obviate the need for pretreatment sentinel node biopsy, because the completion of axillary surgery is typically performed after therapy [2,117]. US-Guided Fine Needle Aspiration Biopsy Axillary Node There is no evidence to support US-guided sampling as the initial imaging test for axillary lymph node evaluation. However, US-guided axillary lymph node sampling is typically the next study performed when axillary imaging is suspicious for metastatic disease.