Stereotactic localization biopsy
Stereotactic localization biopsy is a newer approach that relies on a three-dimensional x-ray to guide the needle biopsy of a nonpalpable mass. With one type of equipment, the patient lies face down on an examining table with a hole in it that allows the breast to hang through; the x-ray machine and the maneuverable needle "gun" are set up underneath. Alternatively, specialized stereotactic equipment can be attached to a standard mammography machine.
The breast is x-rayed from two different angles and a computer plots the exact position of the suspicious area. (Because only a small area of the breast is exposed to the radiation, the doses are similar to those from standard mammography.) Once the target is clearly identified, the radiologist positions the gun and advances the biopsy needle into the lesion.