Sentinel node biopsy for breast cancer: past, present, and future.

Sentinel node biopsy has replaced axillary lymph node dissection as the standard of care in early breast cancers. Sentinel node biopsy represents a highly accurate and less-morbid axillary staging, which allows most patients to avoid unnecessary axillary lymph node dissection and its morbidity. This review provides information including several issues which are still under debate, such as clinical significance of micrometastases, avoidance of axillary lymph node dissection for patients with positive sentinel nodes, accuracy and timing of sentinel node biopsy in patients undergoing neoadjuvant chemotherapy, and how many sentinel nodes are sufficient for removal. Finally, a new topic is introduced: superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging for the detection of metastases in sentinel nodes localized by computed tomography (CT)-lymphography (CT-LG) in patients with breast cancer. SPIO-enhanced MR imaging is a useful method of detecting metastases in sentinel nodes localized by CT-LG in patients with breast cancer. Patients with clinically negative nodes may be spared even sentinel node biopsy when the sentinel node is diagnosed as disease free using SPIO-enhanced MR imaging.