Role of stereotactic biopsy in diagnosing breast cancer.

Only 10% to 20% of nonpalpable breast lesions are malignant, yet all suspicious lesions must undergo biopsy. For many women with breast abnormalities, needle biopsy is a less expensive, quicker and better tolerated alternative to surgical excisional biopsy. Localization techniques that may be used during needle biopsy include clinical guidance, the grid coordinate system, ultrasound guidance and stereotactic guidance. Of these four options, only stereotactic guidance permits localization of a lesion in three dimensions. This article explains the principles behind stereotactic localization and discusses the equipment and personnel involved in the stereotactic breast biopsy procedure. It also discusses patient positioning techniques and sampling technique during stereotactic breast biopsy, with particular emphasis on the mammographer's role throughout the procedure.