However, these studies were performed by breast radiologists with extensive experience in sonographic locoregional staging of breast cancer, and it is not clear to what degree these results would be reproducible in other centers. Therefore, although staging of the axilla via US is recommended, there is no evidence to support whole-breast US for locoregional staging in pregnant patients at this time. US Axilla Sonographic evaluation of the axilla is often performed to stage pregnant patients who are diagnosed with breast cancer. In a study of 23 pregnant patients undergoing neoadjuvant chemotherapy for newly diagnosed breast cancer, 15 of 18 axillary metastases were correctly diagnosed by sonographic evaluation of the axilla [50]. MRI Breast It is well established that IV gadolinium chelates cross the placenta and enter the fetal circulation. Although there are no reported adverse fetal effects due to IV gadolinium in the pregnant mother, there is the potential for the dissociation of free toxic gadolinium ion with limited data in this patient population. Guidelines regarding gadolinium administration during pregnancy are outlined in detail in the ACR Manual on Contrast Media [33]. Because of the concerns regarding gadolinium crossing the placenta and limited data regarding its safety in this setting, breast DCE-MRI is therefore not recommended in pregnant women. However, immediately following delivery or pregnancy termination, breast MRI is recommended for locoregional staging. A small series evaluating PABC on breast MRI showed that 23% of patients had pathologically proven greater extent of disease than was identified with mammography and breast US. This study showed variable background parenchymal enhancement with 58% of patients demonstrating moderate or marked enhancement. Despite increased background parenchymal enhancement, this study showed 98% sensitivity for PABC [19].
Breast Imaging of Pregnant and Lactating Women. However, these studies were performed by breast radiologists with extensive experience in sonographic locoregional staging of breast cancer, and it is not clear to what degree these results would be reproducible in other centers. Therefore, although staging of the axilla via US is recommended, there is no evidence to support whole-breast US for locoregional staging in pregnant patients at this time. US Axilla Sonographic evaluation of the axilla is often performed to stage pregnant patients who are diagnosed with breast cancer. In a study of 23 pregnant patients undergoing neoadjuvant chemotherapy for newly diagnosed breast cancer, 15 of 18 axillary metastases were correctly diagnosed by sonographic evaluation of the axilla [50]. MRI Breast It is well established that IV gadolinium chelates cross the placenta and enter the fetal circulation. Although there are no reported adverse fetal effects due to IV gadolinium in the pregnant mother, there is the potential for the dissociation of free toxic gadolinium ion with limited data in this patient population. Guidelines regarding gadolinium administration during pregnancy are outlined in detail in the ACR Manual on Contrast Media [33]. Because of the concerns regarding gadolinium crossing the placenta and limited data regarding its safety in this setting, breast DCE-MRI is therefore not recommended in pregnant women. However, immediately following delivery or pregnancy termination, breast MRI is recommended for locoregional staging. A small series evaluating PABC on breast MRI showed that 23% of patients had pathologically proven greater extent of disease than was identified with mammography and breast US. This study showed variable background parenchymal enhancement with 58% of patients demonstrating moderate or marked enhancement. Despite increased background parenchymal enhancement, this study showed 98% sensitivity for PABC [19].