Mammographic Guidewire Localization
Detection of Breast Lesions
Guidewire-directed biopsy is the predominant method of evaluating non palpable breast lesions detected by mammography. It is an accurate and safe procedure for obtaining a histologic evaluation of abnormal tissue, leading to early diagnosis and improved survival rates.
After needle biopsy, some of these lesions may require diagnostic or therapeutic surgical biopsy. If a malignant or indefinite diagnosis is obtained, surgical intervention is indicated. This, in turn, requires accurate localization of the lesion, which is required to ensure correct and adequate removal of the lesions and to minimize the degree of cosmetic disfigurement.
Techniques that involve mammography usually require the upright mammographic attachment on a normal mammographic unit, although localizations with stereotactic prone tables are also available. Before stereotaxy came into use, a grid or holey plate was used to calculate the position of needle placement in the X and Y planes.
Grid technique of localization.
The depth and postion of the needle is calculated from the lateromedial and a cranio caudial projection.
Orthogonal (mediolateral) projection confirms the position of the needle to be placed beyond the cluster of microcalcification.
After successful placement of a guidewire, the patient is then taken to the operating room, where the surgeon commonly makes an incision at the site of the wire insertion and excises the wire and the lesion. Some surgeons place a stiff outer cannula along the wire down to the wire tip and excise the tip along with the lesion.