FDG-PET/CT Skull Base to Mid-Thigh FDG-PET/CT is not routinely used for initial imaging of the clinically node-negative axilla before NAC because of its low sensitivity and specificity for detecting nodal disease [4]. 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. However, when an FDG-avid axillary node is seen on a pretreatment PET/CT scan, this is highly predictive of metastasis [111]. Mammography Diagnostic There is no relevant literature to support the use of diagnostic mammography in 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. MRI Breast Without and With IV Contrast There is robust evidence to support MRI for determining the extent of disease in the breast, both before and after NAC [1,4,31,32,35,36,43,63-66]. Although the axillary lymph nodes are included on MRI, it is only moderately sensitive for the detection of axillary nodal metastasis before and after therapy [4,112,113]. Therefore, MRI is not typically obtained solely for the purpose of staging the clinically node-negative axilla before NAC [4]. MRI Breast Without IV Contrast There is no relevant literature to support the use of MRI breast without IV contrast in initial imaging evaluation of the axilla before NAC. US Axilla Current National Comprehensive Cancer Network practice guidelines recommend considering axillary US and possible biopsy before starting NAC, even in clinically node-negative patients [115,116].
Monitoring Response to Neoadjuvant Systemic Therapy for Breast Cancer. FDG-PET/CT Skull Base to Mid-Thigh FDG-PET/CT is not routinely used for initial imaging of the clinically node-negative axilla before NAC because of its low sensitivity and specificity for detecting nodal disease [4]. 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. However, when an FDG-avid axillary node is seen on a pretreatment PET/CT scan, this is highly predictive of metastasis [111]. Mammography Diagnostic There is no relevant literature to support the use of diagnostic mammography in 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. MRI Breast Without and With IV Contrast There is robust evidence to support MRI for determining the extent of disease in the breast, both before and after NAC [1,4,31,32,35,36,43,63-66]. Although the axillary lymph nodes are included on MRI, it is only moderately sensitive for the detection of axillary nodal metastasis before and after therapy [4,112,113]. Therefore, MRI is not typically obtained solely for the purpose of staging the clinically node-negative axilla before NAC [4]. MRI Breast Without IV Contrast There is no relevant literature to support the use of MRI breast without IV contrast in initial imaging evaluation of the axilla before NAC. US Axilla Current National Comprehensive Cancer Network practice guidelines recommend considering axillary US and possible biopsy before starting NAC, even in clinically node-negative patients [115,116].