Stereotactic breast biopsy: comparison of 14- and 11-gauge Mammotome probe performance and complication rates

The purpose of this study was to compare specimen weights, tissue acquisition times, and complication rates for 14- and 11-gauge Mammotome probes during stereotactic breast biopsy. Three hundred forty stereotactic Mammotome breast biopsies were reviewed for complications; 269 (79%) of these biopsies were performed with the 14-gauge Mammotome probe, and 71 (21%) with the 11-gauge probe. Aggregate specimen weights and tissue acquisition times were measured in 248 out of 340 stereotactic Mammotome breast biopsies. Of these 248 lesions, 186 (75%) were performed with the 14-gauge probe, and 62 (25%) with the 11-gauge probe. Complication rates were essentially the same for each probe: 1.1 per cent for the 14-gauge probe and 1.4 per cent for the 11-gauge probe (not significant). More total aggregate breast tissue was obtained during the biopsies performed with the 11-gauge Mammotome probes than with the 14-gauge probes (1730 versus 1067 mg; P < or = 0.0001). The number of specimens acquired was smaller during the 11-gauge biopsy sessions (18 versus 27; P < or = 0.0001). The average per-specimen weight was significantly higher with the 11-gauge probe: 96 versus 40 mg per specimen (P < or = 0.0001). The average tissue harvesting time was approximately the same with each probe size, 15.6 minutes for the 11-gauge probe and 15.4 for the 14-gauge probe (not significant). Consequently, the harvesting rate (mg of tissue obtained per minute) was 111 mg/minute with the 11-gauge probe versus 69 with the 14-gauge probe (P < or = 0.0001). The per-specimen breast tissue yield, using the 11-gauge probe, was more than two times greater than the yield using the 14-gauge probe. There was no increase in procedure time, and there were no additional complications.