A new lateral guidance device for stereotactic breast biopsy using an add-on unit to an upright mammography system

Stereotactic breast biopsy (SBB) is the gold standard for noninvasive breast cancer diagnosis. Current systems rely on one of two methods for needle insertion: a vertical-approach (from above the breast compression plate) or a lateral-approach (parallel to the compression plate). While the vertical-approach is more commonly used, it is not feasible in patients with thin breasts (less than 3 cm thickness after compression) or with superficial lesions. We present a novel design of lateral guidance device for SBB which addresses these limitations of the vertical-approach, and provides improvements over existing lateral guidance hardware. This device incorporates spherical linkages to allow two degrees of rotational freedom in the needle trajectory for increased targeting flexibility, as well as an adjustable rigid needle support to minimize needle deflection within the tissue. Needle placement error in SBB experiments is compared using both the new lateral guidance device and a commercial lateral guidance device in agar phantoms. The effect of elevation angle on needle placement accuracy using the new lateral guidance device is also assessed. Finally, a biopsy accuracy experiment is presented using a certified SBB phantom to compare the new design and the commercial lateral guidance device. In these experiments, SBB performed using the new lateral guidance device resulted in improved needle placement error and biopsy accuracy, while increasing targeting flexibility and maintaining procedural workflow.