RESUMEN
Many patients with breast cancer are candidates for breast conservation therapy. This group includes individuals with small nonpalpable tumors detected at screening mammography and those with sufficient tumor shrinkage after neoadjuvant chemotherapy. Breast conservation surgery often requires the use of an imaging-guided preoperative localization procedure, during which a device is placed within or adjacent to the target lesion to guide the surgeon intraoperatively. For decades, wire localization has been the standard for preoperative localization in breast imaging. With this method, a wire is placed in the breast percutaneously, with the distal wire segment positioned adjacent to the abnormality and the proximal wire segment remaining outside the breast. Because of the external component of the wire, the patient must be compliant, and care must be taken to not disturb the wire's position before surgery. Scheduling flexibility is also limited because the wire localization must be performed on the same day as the subsequent surgery. More recently, the available options for performing preoperative localization have expanded greatly and now include the use of nonwire devices such as radioactive and magnetic seeds, radar reflectors, and radiofrequency identification tags. Nonwire localization devices can be placed days in advance of the surgery, at the patient's convenience, to avoid wire-related challenges and complications. They are placed percutaneously within or adjacent to the target breast lesion and detected intraoperatively by using a probe outside the breast.©RSNA, 2019.