Learning curve for stereotactic breast biopsy: how many cases are enough?
OBJECTIVE
The objective of this study was to evaluate the learning curve for stereotactic breast biopsy.


METHODS
Retrospective review was performed of 923 consecutive lesions that underwent stereotactic breast biopsy performed by one of six radiologists. Four hundred fourteen lesions had 14-gauge automated core biopsy, and 509 subsequent lesions had vacuum-assisted biopsy (14-gauge in 163 and 11-gauge in 346). Medical records were reviewed to determine the technical success rate and false-negative rate as a function of operator experience.


RESULTS
For 14-gauge automated core biopsy, a significantly lower technical success rate was seen for the first five cases of each radiologist than for subsequent cases (25/30 = 83.3% versus 366/384 = 95.3%, p < 0.02) and for the first 20 cases than for subsequent cases (90/100 = 90% versus 284/296 = 95.9%, p < 0.05). For 11-gauge vacuum-assisted biopsy, a significantly lower technical success rate was seen for the first five cases than for subsequent cases (17/20 = 85.0% versus 310/322 = 96.3%, p < 0.05) and for the first 15 cases than for subsequent cases (54/60 = 90.0% versus 273/283 = 96.5%, p = 0.03). The false-negative rate was higher for the first 15 cases compared with subsequent cases both for stereotactic 14-gauge automated core biopsy (4/31 = 12.9% versus 3/115 = 2.6%, p < 0.04) and for stereotactic 11-gauge vacuum-assisted biopsy (2/27 = 7.4% versus 0/85 = 0%, p < 0.06).


CONCLUSIONS
A learning curve exists for stereotactic breast biopsy. Significantly higher technical success rates and lower false-negative rates were observed after the first five to 20 cases for 14-gauge automated core biopsy and after the first five to 15 cases for 11-gauge vacuum-assisted biopsy. Even after a radiologist has experience with stereotactic biopsy, changes in equipment may result in a new learning curve.
Breast Imaging Section, Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave., New York, NY 10021, USA.
L
L
Liberman
C L
CL
Benton
D D
DD
Dershaw
A F
AF
Abramson
L R
LR
LaTrenta
E A
EA
Morris
D001707:Biopsy, Needle / Q000379:methods*; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000473:pathology; D002983:Clinical Competence; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D015641:Radiography, Interventional; D012189:Retrospective Studies; D013048:Specimen Handling