The goals of needle localization are to assist the surgeon in removing a nonpalpable breast mass that is suspicious or highly suggestive of malignancy and to minimize the amount of tissue that must be sacrificed in the process. Although a variety of techniques can be used for needle localization, today it is most commonly performed with hook wires or retractable curved wires. Imaging guidance for localization may be provided by mammography or ultrasound.
To perform mammographic-guided hook-wire localization, the patient usually sits with the breast in a fenestrated compression paddle with an alphanumeric grid. An image is obtained, coordinates of the lesion in two dimensions are determined, and a needle is placed to the appropriate depth as determined from review of the films taken prior to the procedure. Following needle placement, two orthogonal views are obtained. When the needle is in good position, the wire is deployed and the needle is removed. Two orthogonal views are obtained, labeled and sent with the patient for use in the operating suite. Removal of the lesion should be confirmed with specimen radiography.
The most common complication of needle localization is vasovagal reaction, which occurred in 27 of 370 (7%) patients who underwent needle localization or fine-needle aspiration in a series by Helvie et al.
Vasovagal reactions may range from lightheadedness to syncope (the latter occurred in 2 of 370=1% cases in the study of Helvie et al ). Prolonged bleeding occurred in 3 of 370 (1%) cases and pain in 2 of 370 (1%). Pneumothorax is exceedingly rare in localizations performed parallel to the chest wall. Other complications such as migration of wire fragments are also extremely unusual. Retention of wire fragments following localization has been reported but is thought to be of no clinical consequence.
The incidence of “missed lesions” at needle localization has ranged in published series from 0-18%. Jackman et al recently reviewed findings in 280 consecutive nonpalpable breast lesions that underwent needle localization.
Biopsy failed in 7 (2.5%) of 280 lesions. Unsuccessful needle localization was more likely with two lesions per breast, small lesions, small specimens and microcalcifications. Removal of more than one tissue specimen converted failure to success in 14 (67%) of 21 initially missed microcalcification lesions.
Image-Guided Percutaneous Breast Biopsy
Percutaneous image-guided breast biopsy is being used increasingly as an alternative to surgical biopsy for the evaluation of lesions that can be seen with mammography or ultrasound. Percutaneous biopsy methods differ with respect to the method of imaging guidance (most commonly stereotaxis or ultrasound) and the tissue-acquisition device (fine needle, automated core needle, directional vacuum-assisted biopsy probe, biopsy cannula, and others).
Laura Liberman and Timothy L. Feng
Breast cancer detection demonstration project: five-year summary report. CA 2003