FROM THE RSNA REFRESHER COURSES - PERFORMING A BREAST BIOPSY WITH A DIRECTIONAL, VACUUM-ASSISTED BIOPSY INSTRUMENT

A recently developed method of minimally invasive breast biopsy involv es use of a directional, vacuum-assisted instrument. Use of this instr ument requires some changes in techniques and applications of breast b iopsy, but it enables confident biopsy of breast lesions under both ul trasound (US) and stereotactic guidance. The device uses vacuum to pul l tissue into the probe and to remove the specimen without withdrawing the probe each time. For stereotactic biopsy, to target the lesion, t he probe is placed anterior or posterior to the lesion and stereotacti c positioning views are obtained; for a US-guided procedure, the probe is advanced posterior to the lesion. Next, the direction that the pro be aperture must be rotated to face the lesion is determined. Tissue s amples are obtained at consecutive clock positions of 1 1/2-hour inter vals to achieve contiguous sampling. At least 15 samples are obtained with an 11-gauge probe to acquire a minimum of 1,500 mg of tissue. If postbiopsy images reveal that the lesion has been removed, a percutane ous clip is placed to mark the biopsy site for follow-up examination a nd possible further treatment. Patients are examined the next day and given the biopsy results and treatment considerations, if needed; they are followed up approximately 1 week later to detect any complication s leg, discomfort, ecchymosis). By learning how to perform a direction al, vacuum-assisted biopsy with either stereotactic or US guidance, th e radiologist has an additional, valuable tool for bringing accurate b reast biopsy to his or her community.