Overall, US-guided FNA 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]. Variant 4: Adult female or male or transfeminine (male-to-female) or transmasculine (female-to-male). Known breast cancer, clinically node-positive. Axillary evaluation prior to neoadjuvant chemotherapy. Initial imaging. Digital Breast Tomosynthesis Diagnostic There is no relevant literature to support the use of DBT in the initial imaging evaluation of the axilla before NAC. Mammography or DBT is performed for initial diagnosis of the primary breast cancer. This procedure incompletely images the axilla, although pathologically enlarged stage I and II nodes may be included on the lateral and mediolateral oblique projections. FDG-PET/CT Skull Base to Mid-Thigh FDG-PET/CT may be useful for staging and restaging clinically node-positive patients undergoing NAC [4]. In node-positive patients, the decrease in standardize uptake value from pre- to posttreatment scans can be used to monitor response and help predict pCR [116]. This possibly may lead to less aggressive axillary surgery upon completion of chemotherapy rather than complete lymph node dissection [118]. In several studies on detection of nodal disease, including a multicenter study of 360 patients, PET had disparate sensitivities (43%-79%) and specificities (66%-93%), possibly related to differences in tumor size in patient populations [109,110]. Given these limitations, surgical sampling of the axillary nodes remains the standard of care.
Monitoring Response to Neoadjuvant Systemic Therapy for Breast Cancer. Overall, US-guided FNA 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]. Variant 4: Adult female or male or transfeminine (male-to-female) or transmasculine (female-to-male). Known breast cancer, clinically node-positive. Axillary evaluation prior to neoadjuvant chemotherapy. Initial imaging. Digital Breast Tomosynthesis Diagnostic There is no relevant literature to support the use of DBT in the initial imaging evaluation of the axilla before NAC. Mammography or DBT is performed for initial diagnosis of the primary breast cancer. This procedure incompletely images the axilla, although pathologically enlarged stage I and II nodes may be included on the lateral and mediolateral oblique projections. FDG-PET/CT Skull Base to Mid-Thigh FDG-PET/CT may be useful for staging and restaging clinically node-positive patients undergoing NAC [4]. In node-positive patients, the decrease in standardize uptake value from pre- to posttreatment scans can be used to monitor response and help predict pCR [116]. This possibly may lead to less aggressive axillary surgery upon completion of chemotherapy rather than complete lymph node dissection [118]. In several studies on detection of nodal disease, including a multicenter study of 360 patients, PET had disparate sensitivities (43%-79%) and specificities (66%-93%), possibly related to differences in tumor size in patient populations [109,110]. Given these limitations, surgical sampling of the axillary nodes remains the standard of care.