Objective: The purpose of this study was to compare the outcome of sonographically guided core biopsies performed with the 14-gauge automated gun with the outcome of those performed with the 11-gauge vacuum-assisted device. Outcome was defined in terms of missed tumors, the need (both immediate and delayed) for a second biopsy, histologic underestimation, and complication rates.
Materials and methods: We retrospectively reviewed all sonographically guided core biopsies performed between January 1997 and August 2001. Before February 2000, biopsies were performed using the 14-gauge automated gun and after that time, with either the 14-gauge automated gun or the 11-gauge vacuum-assisted device. During the study period, 181 biopsies were performed with the 14-gauge automated gun and 100 with the 11-gauge vacuum-assisted device.
Results: The histologic results of the core biopsies were similar for the group who underwent biopsy with the 14-gauge automated gun and the group who underwent biopsy with the 11-gauge vacuum-assisted device: malignant, 19% versus 19%; benign, 78% versus 79%; and high-risk lesion or other, 3% versus 2%, respectively (p > 0.7). Complications were rare and similar for both methods: 2% for the 14-gauge automated gun and 3% for the 11-gauge vacuum-assisted device (p = 0.46). A second biopsy was recommended immediately after the first in 14% of the patients who underwent biopsy with the 14-gauge automated gun versus 17% of those who underwent biopsy with the 11-gauge vacuum-assisted device (p = 0.47). Recommendation for delayed rebiopsy due to interval change occurred in 2.5% of the patients who underwent biopsy with the 14-gauge automated gun method and 3% of those who underwent biopsy with the 11-gauge vacuum-assisted device (p = 0.94).
Conclusion: No significant differences were found in the outcomes of sonographically guided core biopsies performed with the automated gun compared with those performed with the vacuum-assisted device in terms of missed cancers, underestimation, complications, or the need (immediate or delayed) for a second biopsy.