Comparison of automated versus vacuum-assisted biopsy methods for sonographically guided core biopsy of the breast

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.     

Nonpalpable breast lesions: stereotactic automated large-core biopsies.

One hundred two patients with mammographically suspicious, nonpalpable lesions underwent stereotactic breast biopsy with a biopsy gun and an automated 14-gauge cutting needle. After biopsy, a localization wire was placed and surgical biopsy performed. There was agreement of the histologic results from the gun biopsy and the surgical biopsy specimens in 98 cases (96%), including 22 of 23 carcinomas (96%) (kappa = 0.936). The gun biopsy yielded findings that led to the correct diagnosis in two cases involving lesions that were missed at surgical biopsy; two lesions found at surgery were missed at gun biopsy. The results of this study suggest that the use of 14-gauge needles improves agreement between surgical and needle core biopsy findings and that stereotactic biopsy with an automated needle and gun can be an acceptable alternative to surgical biopsy in women with mammographically suspicious breast lesions.     

Sonographically Guided Core Biopsy of the Breast: Comparison of 14-Gauge Automated Gun and 11-Gauge Directional Vacuum-Assisted Biopsy Methods

Objective

To compare the outcomes of 14-gauge automated biopsy and 11-gauge vacuum-assisted biopsy for the sonographically guided core biopsies of breast lesions.

Materials and Methods

We retrospectively reviewed all sonographically guided core biopsies performed from January 2002 to February 2004. The sonographically guided core biopsies were performed with using a 14-gauge automated gun on 562 breast lesions or with using an 11-gauge vacuum-assisted device on 417 lesions. The histologic findings were compared with the surgical, imaging and follow-up findings. The histologic underestimation rate, the repeat biopsy rate and the false negative rates were compared between the two groups.

Results

A repeat biopsy was performed on 49 benign lesions because of the core biopsy results of the high-risk lesions (n = 24), the imaging-histologic discordance (n = 5), and the imaging findings showing disease progression (n = 20). The total underestimation rates, according to the biopsy device, were 55% (12/22) for the 14-gauge automated gun biopsies and 36% (8/22) for the 11-gauge vacuum-assisted device (p = 0.226). The atypical ductal hyperplasia (ADH) underestimation (i.e., atypical ductal hyperplasia at core biopsy and carcinoma at surgery) was 58% (7/12) for the 14-gauge automated gun biopsies and 20% (1/5) for the 11-gauge vacuum-assisted biopsies. The ductal carcinoma in situ (DCIS) underestimation rate (i.e., ductal carcinoma in situ upon core biopsy and invasive carcinoma found at surgery) was 50% (5/10) for the 14-gauge automated gun biopsies and 41% (7/17) for the 11-gauge vacuum-assisted biopsies. The repeat biopsy rates were 6% (33/562) for the 14-gauge automated gun biopsies and 3.5% (16/417) for the 11-gauge vacuum-assisted biopsies. Only 5 (0.5%) of the 979 core biopsies were believed to have missed the malignant lesions. The false-negative rate was 3% (4 of 128 cancers) for the 14-gauge automated gun biopsies and 1% (1 of 69 cancers) for the 11-gauge vacuum-assisted biopsies.

Conclusion

The outcomes of the sonographically guided core biopsies performed with the 11-gauge vacuum-assisted device were better than those outcomes of the biopsies performed with the 14-gauge automated gun in terms of underestimation, rebiopsy and the false negative rate, although these differences were not statistically significant.     

Stereotactic breast biopsy of noncalcified lesions: a cost-minimization analysis comparing 14-gauge multipass automated core biopsy to 14- and 11-gauge vacuum-assisted biopsy

A decision model was used to compare the relative costs of the 14-gauge automated gun technique to the 14-gauge and 11-gauge vacuum-assisted techniques for stereotactic biopsy of noncalcified breast lesions. Probability and cost variables were estimated from clinical experience with 76 automated gun biopsies, seventy-eight 14-gauge vacuum-assisted biopsies and thirty-nine 11-gauge vacuum-assisted biopsies. The 14-gauge automated gun was the preferred strategy from a cost standpoint: the 14-gauge vacuum technique was 1.19 times more expensive, and the 11-gauge was 1.22 times more expensive.     

Stereotactic histologic biopsy with patients prone: technical feasibility in 98% of mammographically detected lesions

OBJECTIVE: The purpose of this retrospective study was to determine which mammographically detected lesions in need of imaging-guided biopsy could undergo prone, stereotactic biopsy. MATERIALS AND METHODS: From July 1991 through June 2001, 1687 consecutive patients (age range, 29-94 years; median age, 58 years) with 1894 lesions were referred by clinicians in a multispecialty clinic. The patients underwent stereotactic, prone, histologic biopsy of 1851 lesions (98%) and needle-localized breast biopsy of 43 lesions (2%). We performed stereotactic biopsies successively with 14-gauge automated large-core devices and 14- or 11-gauge vacuum-assisted devices. We evaluated lesions by patient, breast, lesion, and procedural variables to determine why stereotactic biopsy was not performed. RESULTS: Of 1851 lesions referred for stereotactic biopsy, biopsies were canceled in 42 lesions (2%) not considered suspicious enough to warrant biopsy. Of 1809 lesions in which stereotactic biopsy was considered to be warranted, stereotactic biopsy was canceled for technical reasons in 29 lesions (2%). Of 43 lesions referred for surgical biopsy, stereotactic biopsy was thought to be technically problematic in five (12%). Inability to accomplish a stereotactic biopsy in 34 (2%) of 1852 lesions needing a biopsy was due to proximity to the chest wall (n = 10, 29%), inadequate lesion visualization unrelated to lesion depth (n = 19, 56%), and patient factors (n = 5, 15%). CONCLUSION: Stereotactic biopsy had a technical success rate of 98% (1780/1809) and was used for histologic diagnosis in 96% (1780/1852) of mammographically detected lesions. Inadequate lesion visualization accounted for 85% (29/34) of stereotactic biopsy failures.     

Atypical ductal hyperplasia and ductal carcinoma in situ as revealed by large-core needle breast biopsy: results of surgical excision

OBJECTIVE: This investigation compares the frequency of histologic underestimation of breast carcinoma that occurs when a large-core needle biopsy reveals atypical ductal hyperplasia or ductal carcinoma in situ with the automated 14-gauge needle, the 14-gauge directional vacuum-assisted biopsy device, and the 11-gauge directional vacuum-assisted biopsy device. SUBJECTS AND METHODS: Evaluation of 428 large-core needle biopsies yielding atypical ductal hyperplasia (139 lesions) or ductal carcinoma in situ (289 lesions) was performed. The results of subsequent surgical excision were retrospectively compared with the needle biopsy results. RESULTS: For lesions initially diagnosed as ductal carcinoma in situ, underestimation of invasive ductal carcinoma was significantly less frequent using the 11-gauge directional vacuum-assisted biopsy device when compared with the automated 14-gauge needle (10% versus 21%, p < 0.05) but was not significantly less frequent when compared with the 14-gauge directional vacuum-assisted device (10% versus 17%, p > 0.1). For lesions diagnosed initially as atypical ductal hyperplasia, underestimation of ductal carcinoma in situ and invasive ductal carcinoma was significantly less frequent using the 11-gauge directional vacuum-assisted biopsy device compared with the 14-gauge directional vacuum-assisted device (19% versus 39%, p = 0. 025) and with the automated 14-gauge needle (19% versus 44%, p = 0. 01). CONCLUSION: The frequency of histologic underestimation of breast carcinoma in lesions initially diagnosed as atypical ductal hyperplasia or ductal carcinoma in situ using large-core needle biopsy is substantially lower with the 11-gauge directional vacuum-assisted device than with the automated 14-gauge needle and with the 14-gauge directional vacuum-assisted device.     

Stereotactic biopsy of ductal carcinoma in situ of the breast using an 11-gauge vacuum-assisted device: persistent underestimation of disease.

OBJECTIVE: The purpose of this study was to compare the diagnostic accuracy of 14-gauge automated gun and 11-gauge directional vacuum-assisted biopsy techniques in the diagnosis of ductal carcinoma in situ of the breast. MATERIALS AND METHODS: We retrospectively reviewed 41 consecutive lesions that had been diagnosed as ductal carcinoma in situ using stereotactic needle biopsy. The first 21 lesions had been biopsied using a 14-gauge automated gun; the remaining 20 lesions, using an 11-gauge vacuum-assisted device. Surgical histopathologic results at lumpectomy were compared with the findings at needle biopsy and defined as either concordant, when only ductal carcinoma in situ (i.e., no evidence of invasive carcinoma) was evident at surgery, or discordant, when invasive carcinoma was found. One patient from the automated gun group was lost to follow-up and was not included in the analysis. RESULTS: Invasive carcinoma was found at surgery in seven (35%) of the 20 cases diagnosed using the automated gun compared with three (15%) of the 20 cases diagnosed using the vacuum-assisted device (p = .13). In all three of these discordant vacuum-assisted cases, only microinvasive disease was found at surgery. However, in only two of the seven discordant automated gun cases was only microinvasive disease found at surgery. CONCLUSION: The 11-gauge directional vacuum-assisted biopsy technique may improve the accuracy of ductal carcinoma in situ diagnosis. Underestimation of disease still occurs, however.     

Stereotactic biopsy of noncalcified breast lesions: utility of vacuum-assisted technique compared to multipass automated gun technique

The purpose of this study was to evaluate the stereotactic 14-gauge, vacuum-assisted biopsy technique in diagnosing noncalcified breast lesions. Stereotactic biopsy of 116 noncalcified breast lesions was performed with either 14-gauge, vacuum-assisted technique or multipass, automated large-core technique. The number of core samples and time required for each biopsy were compared. Outcome for each technique was compared based on recommendations after the mammographic-histologic review process. Results from surgical excision and mammographic follow-up were reviewed. The vacuum-assisted technique obtained more tissue cores per lesion than the automated gun technique, showed marginal decrease in number of repeat biopsies for discordant results, and required fewer short-term follow-up mammograms, although the difference did not achieve statistical significance. The vacuum-assisted technique can be used successfully to sample noncalcified breast masses, with marginal improvement over the automated gun technique.     

Calcifications highly suggestive of malignancy: comparison of breast biopsy methods.

OBJECTIVE: The purpose of this study was to compare the usefulness of, and cost of diagnosing with, different breast biopsy methods for women with calcifications highly suggestive of malignancy. MATERIALS AND METHODS: One hundred thirty-nine women with calcifications highly suggestive of malignancy underwent diagnostic biopsy. Of these, 89 women had stereotactic biopsy with a 14-gauge automated needle (n = 25), 14-gauge vacuum-assisted probe (n = 17), or 11-gauge vacuum-assisted probe (n = 47); and 50 women had diagnostic surgical biopsy. Medical records were reviewed. Cost savings for stereotactic biopsy were calculated using Medicare data. RESULTS: The median number of operations was one for women who had stereotactic biopsy versus two for women who had diagnostic surgical biopsy. The likelihood of undergoing a single operation was significantly greater for women who had stereotactic rather than surgical biopsy, among all women (61/89 [68.5%] vs. 19/50 [38.0%], p < 0.001) and among women treated for breast cancer (55/77 [71.4%] vs. 6/37 [16.2%], p = 0.0000001). Stereotactic 11-gauge vacuum-assisted biopsy, as compared with 14-gauge automated core or 14-gauge vacuum-assisted biopsy, was significantly more likely to spare a surgical procedure (36/47 [76.6%] vs. 16/42 [38.1%], p = 0.0005). Stereotactic 11-gauge vacuum-assisted biopsy resulted in the greatest cost reduction, yielding savings of $315 per case compared with diagnostic surgical biopsy; for women with solitary lesions, stereotactic 11-gauge biopsy decreased the cost of diagnosis by 22.2% ($334/$1502). CONCLUSION: For women with calcifications highly suggestive of malignancy, the use of stereotactic rather than surgical biopsy decreases the number of operations. Stereotactic 11-gauge vacuum-assisted biopsy, as compared with 14-gauge automated core or 14-gauge vacuum-assisted biopsy, is significantly more likely to spare a surgical procedure and has the highest cost savings.     

Comparison of rebiopsy rates after stereotactic core needle biopsy of the breast with 11-gauge vacuum suction probe versus 14-gauge needle and automatic gun

OBJECTIVE: The 11-gauge vacuum suction probe is an alternative to the 14-gauge needle and automatic gun for performing stereotactic core needle biopsies. This study compares rebiopsy rates after stereotactic core needle biopsies that were performed with the two methods. The study also assesses the outcomes of those repeat biopsies. MATERIALS AND METHODS: Five hundred ninety-two stereotactic core needle biopsies using a 14-gauge needle and automatic gun and 354 using an 11-gauge vacuum suction probe were performed consecutively. Excluding malignancies, the number of cases requiring rebiopsy and the reasons for rebiopsy were determined for each group. The histologic diagnoses of the repeat biopsies were assessed. RESULTS: The rebiopsy rate was significantly lower with the 11-gauge vacuum suction probe (9.0%) than with the 14-gauge needle and automatic gun (14.9%) (p = .013). Significant reductions were found in cases of insufficient sampling (probe, 1.7%; needle, 4.4%; p = .042) and mammographic-pathologic discrepancy (probe, 0.8%; needle, 3.4%; p = .026). The rebiopsy rate for masses was 6.1% with the vacuum probe versus 10.7% with the 14-gauge needle (p = .12) and for calcifications was 11.6% with the vacuum probe versus 23.7% with the 14-gauge needle (p = .003). After rebiopsy, the percentage of cases in which malignancy was found was 18.5% with the vacuum probe versus 13.7% with the 14-gauge needle. On rebiopsy, the percentage of malignancies found in each category were atypical hyperplasia: probe 26.7%, needle 20.0%; insufficient sample: probe 0%, needle 9.5%; pathologist recommendation: probe 50.0%, needle 12.5%; and lobular carcinoma in situ: probe 0%, needle 100%. CONCLUSION: Use of the 11-gauge vacuum-assisted device significantly decreases but does not eliminate the need for rebiopsy after stereotactic core needle biopsy. The rebiopsy rate for calcifications was significantly reduced by using the vacuum suction probe rather than the 14-gauge needle; however, the rate for masses was reduced only slightly. On rebiopsy, malignancies were found in both groups.     

Comparison of stereotactic fine needle aspiration cytology and core needle biopsy in 522 non-palpable breast lesions

Purpose: 
To compare the accuracy of stereotactic fine needle aspiration cytologies (S-FNAC) and stereotactic core needle biopsies (S-CNB) in non-palpable breast lesions. Material and Methods: 
Between May 1993 and December 2000, 696 patients with mammographically detected lesions were biopsied both with S-FNAC and S-CNB. S-FNAC was performed with spinal needle 22- or 20-gauge and S-CNB with an automated 14-gauge gun. Results: 
Of the 696 patients, 522 (75%) underwent breast surgery with postoperative histopathology. In all, 448 of these 522 women (86%) had malignant and 74 (14%) had benign lesions. S-FNAC revealed cancer in 254 (57%) and probable cancer in 48 (11%) (sensitivity 68%, specificity 99.6%) and S-CNB revealed cancer in 388 (87%) and probable cancer in 18 (4%) (sensitivity 90%, specificity 98.8%) of these 448 patients. Conclusion: 
S-CNB was more accurate than S-FNAC in the diagnosis of non-palpable breast cancer.     

Benign breast lesions: minimally invasive vacuum-assisted biopsy with 11-gauge needles patient acceptance and effect on follow-up imaging findings

PURPOSE: To evaluate patient acceptance of stereotactic or ultrasonographically (US) guided directional vacuum-assisted 11-gauge needle biopsy of breast lesions and short- and long-term changes at mammography and US resulting from the procedure. MATERIALS AND METHODS: For 91 benign lesions that had been sampled at either stereotactic or US-guided directional vacuum-assisted breast biopsy performed with 11-gauge needles, clinical, mammographic, and US changes were evaluated 1 week after biopsy; 6-month follow-up findings were available for 74 lesions. The subjective outcome of the procedure and patient satisfaction were assessed on the basis of a patient-completed questionnaire that incorporated a multistage scoring system. Statistical analysis of scores for condition for both biopsy methods was performed with the chi2 test. RESULTS: Adverse events occurred during the procedure in four patients. Clinically visible hematomas were observed at 1-week follow-up in 79% of patients. Densities were observed on mammograms in 46% of patients 1 week after biopsy; hematomas with a maximum diameter of 2 cm were seen on sonograms in 74%. Six months after biopsy, mammography revealed discrete architectural changes in one case. No abnormalities were found at 6-month follow-up US. Fifteen patients had various complaints during the procedure; six reported feeling constrained during the first few days after biopsy, and one patient was not satisfied with the cosmetic result. No patient reported a retrospective preference for surgical biopsy instead of directional vacuum-assisted biopsy. Analysis of scores for the stereotactic and US-guided methods revealed a significant difference (P <.001) in favor of the stereotactic method for condition during biopsy, while scores for condition in the first days after biopsy were more equally distributed between the two methods (P =.386). CONCLUSION: Directional vacuum-assisted 11-gauge needle biopsy of the breast is well accepted by patients and rarely produces changes that may alter the mammographic or sonographic appearance of the breast at 6-month follow-up.     

Stereotactic breast biopsy with a biopsy gun

One hundred three patients underwent stereotactic breast biopsy with an 18-, 16-, or 14-gauge cutting needle and a biopsy gun. After biopsy, a localization wire was placed and surgical biopsy performed. There was agreement of the histologic results in 89 cases (87%) including 14 of 16 cancers (87%) (kappa = 0.806). The gun biopsy yielded the correct diagnosis in four cases involving a lesion (including one cancer) that was missed at the surgical biopsy. Nine cases in which the lesion was missed at gun biopsy can be related to insufficient needle size, the greater difficulty in using one of the two stereotactic devices, and early inexperience with the technique. A 14-gauge needle was used in the last 29 biopsies, the results of which agreed with the surgical pathologic findings in 28 cases (97%). With greater experience, stereotactic-guided large-gauge automated percutaneous biopsy may prove to be an acceptable alternative to surgical biopsy in women with breast masses suspected at mammography.     

Metallic marker placement after stereotactic core biopsy of breast calcifications: comparison of two clips and deployment techniques

OBJECTIVE: Two methods of deployment of metallic clips at the site of stereotactic core biopsy for breast calcifications are compared retrospectively. MATERIALS AND METHODS: One hundred nineteen clips deployed through an 11-gauge vacuum-assisted biopsy probe at core biopsy sites were compared with 109 vascular ligating clips deployed at biopsy sites using an 18-gauge spinal needle. The distance of each clip from the position of the target calcification was assessed using stereotactic coordinates in 52 sequential cases and was measured on mammograms before and after biopsy in 108 clips deployed through an 11-gauge probe and 98 clips deployed using an 18-gauge needle. Variance in clip position between postbiopsy and follow-up mammograms was measured in 43 clips placed with an 11-gauge probe and in 44 clips placed with an 18-gauge needle. Comparable measurements of variance in position of fat necrosis calcifications between screening mammograms were used as controls. RESULTS: Ninety-seven percent of the clips placed with an 11-gauge probe and 98% of the clips placed using an 18-gauge needle were within 1 cm of the target calcifications using stereotactic coordinates. On mammograms obtained after biopsy, 70% of the clips placed with an 11-gauge probe and 63% of the clips placed using an 18-gauge needle were within 1 cm of the target calcifications, and the position of 91% of the clips placed with an 11-gauge probe and 90% of the clips placed using an 18-gauge needle varied less than 15 mm on follow-up mammograms. Both clips provided accurate targets for wire-localized excisions. The cost of the 11-gauge needle and clip is $320. The 14-gauge probe, vascular clip, and 18-gauge spinal needle cost $191.58. CONCLUSION: A vascular ligating clip delivered to a stereotactic core biopsy site by an 18-gauge spinal needle is comparable in apparent accuracy and stability to a clip deployed through an 11-gauge probe. This technique allows core biopsies to be performed with instruments smaller than 11-gauge and at a 40% savings in equipment cost.     

Cost-effectiveness of stereotactic 11-gauge directional vacuum-assisted breast biopsy

OBJECTIVE: The purpose of our study was to determine the frequency with which stereotactic 11-gauge directional vacuum-assisted breast biopsy obviated a surgical procedure and to calculate cost savings attributable to that biopsy method. MATERIALS AND METHODS: We retrospectively reviewed 200 consecutive solitary nonpalpable lesions on which stereotactic 11-gauge directional vacuum-assisted breast biopsy was performed. Cost savings were calculated using Medicare reimbursements. Mammograms, histologic findings, and medical records were reviewed. RESULTS: Stereotactic 11-gauge directional vacuum-assisted biopsy obviated a surgical procedure in 151 (76%) of 200 lesions, including 112 (73%) of 154 calcific lesions and 39 (85%) of 46 masses. Reasons for not obviating a surgical procedure in 49 lesions (25%) included recommendation for surgical biopsy in 35 lesions (18%), small carcinomas treated by excision in 10 lesions (5%), and histologic underestimation in four lesions (2%). Stereotactic 11-gauge directional vacuum-assisted biopsy decreased the cost of diagnosis by S264 per case, a 20% ($264/$1289) decrease in the cost of diagnosis compared with surgical biopsy. Of 200 lesions that had stereotactic 11-gauge directional vacuum-assisted biopsy, 106 (53%) would not have been amenable to 14-gauge automated core biopsy because of their small size, their superficial location, or inadequate breast thickness. CONCLUSION: Stereotactic 11-gauge directional vacuum-assisted breast biopsy obviated a surgical procedure in 76% of lesions, yielding a 20% decrease in cost of diagnosis compared with surgical biopsy. Although savings per case are modest, 11-gauge directional vacuum-assisted biopsy expands the spectrum of lesions amenable to stereotactic biopsy, increasing cost savings in the population.     

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. MATERIALS AND 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). CONCLUSION: 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.     

Scar formation after stereotactic vacuum-assisted core biopsy of benign breast lesions

AIM: To evaluate scar formation of impalpable breast lesions with benign histological outcome using stereotactic 11-gauge vacuum-assisted core biopsy (VACB). MATERIALS AND METHODS: Two hundred and ten lesions with benign histology for which follow-up mammograms were available, were assessed for scar formation at the biopsy site. All biopsies were performed using stereotactic VACB with 11-gauge needle. The incidence of post-biopsy scar formation and the number of specimens removed were determined. RESULTS: In 4.3% (9/210) of the lesions for which a biopsy was performed with 11-gauge directional vacuum-assisted technique, the follow-up mammogram revealed a scar formation. Of these, six were minimal scars, two were moderate scars and one was a marked scar. Minimal and moderate scars were diagnosed on imaging only. However, the case with marked scar formation required tissue diagnosis to rule out malignancy. CONCLUSION: Although uncommon, scar formation can be seen in the follow-up mammograms after percutaneous breast biopsies. It is important that the radiologist interpreting follow-up mammograms is aware of the features of this lesion and its relationship to the biopsy procedure.     

Mammographic abnormalities caused by percutaneous stereotactic biopsy of histologically benign lesions evident on follow-up mammograms

OBJECTIVE: The purpose of our study was to evaluate how often a mammographic abnormality thought to be produced by the biopsy procedure was evident on the initial follow-up mammogram after percutaneous biopsy of impalpable histologically benign lesions. We compared three stereotactic percutaneous biopsy methods. CONCLUSION: A mammographic density seen well only in the projection parallel to the biopsy needle tract was evident in 2% (5/226) of the lesions for which 11-gauge directional vacuum-assisted biopsy was used, 0% (0/96) of the lesions for which 14-gauge directional vacuum-assisted biopsy was used, and 0% (0/422) of the lesions for which 14-gauge automated large-core biopsy was used. No mammographic abnormalities assessed as BI-RADS categories 3, 4, or 5 (according to the American College of Radiology's Breast Imaging Reporting and Data System) and thought to be produced by the biopsy procedure were evident after any of the biopsy methods.     

Two-year follow-up of stereotactically guided 9-G breast biopsy: a multicenter evaluation of a self-contained vacuum-assisted device

PurposeTo evaluate the performance of a self-contained, battery-driven, vacuum-assisted breast biopsy (VABB) system for the sampling of clustered breast microcalcifications and masses under stereotactic guidance.Methods and materialsA total of 144 patients (median age: 56 years; range: 21–87 years) in four European breast centers underwent percutaneous 9-gauge (G), stereotactic-guided VABB. The median lesion size was 11 mm (range 2–60 mm). Patients were biopsied in the prone (n=125) or upright position (n=19). All patients were followed up for at least 24 months.ResultsThe stereotactic procedure was successful in 142 (98.6%) of 144 cases, with two cases cancelled due to either severe patient motion (one case) or failure to detect faint calcifications (one case). A median of 12 specimens per procedure was obtained. In 39 cases (27.5%), the suspicious lesion could no longer be detected mammographically after the biopsy procedure. The histological diagnosis was malignancy in 45 (31.7%) cases. One case of atypical ductal hyperplasia diagnosed preoperatively was upgraded to ductal carcinoma in situ (DCIS) at operation, giving an overall sensitivity of 97.7% for the vacuum-assisted biopsy procedure. In two cases where DCIS was diagnosed at vacuum-assisted biopsy, the malignant tissue was apparently completely removed and could no longer be found at operation. No serious complications occurred. During the follow-up period, no breast cancers appeared at the location of biopsy. Six patients dropped out during the follow-up period.ConclusionThe self-contained, vacuum-assisted biopsy device is well suited for stereotactically guided breast biopsies, having demonstrated excellent sensitivity and specificity in the preoperative workup of mammographically detected breast lesions after 2 years of follow-up.     

Stereotactic 11-gauge vacuum-assisted breast biopsy: a validation study

OBJECTIVE: The aim of our study was to determine the false-negative rate of stereotactic 11-gauge vacuum-assisted biopsy in a validation study of lesions that had subsequent surgical excision. MATERIALS AND METHODS: Retrospective review was performed of 318 lesions that underwent stereotactic 11-gauge vacuum-assisted biopsy and subsequent surgical excision. A false-negative case was defined as a pathologically proven cancer in which stereotactic biopsy yielded benign results without atypia. Medical records, imaging studies, and histologic findings were reviewed. RESULTS: False-negative findings were encountered at stereotactic 11-gauge vacuum-assisted biopsy in 3.3% (7/214) of pathologically proven cancers. False-negative findings occurred in 3.5% (4/115) of malignant calcification lesions versus 3.0% (3/99) of malignant masses (p = 1.0). The seven false-negative findings included five Breast Imaging Reporting and Data System (BI-RADS) category 5 lesions that yielded benign results at biopsy, one BI-RADS category 4 mass that benign breast tissue, and one BI-RADS category 4 cluster of calcifications in which no calcifications were retrieved. The false-negative rate was 10.0% (6/60) for radiologists who performed 15 or fewer previous stereotactic vacuum-assisted biopsy procedures versus 0.6% (1/154) for radiologists who performed more than 15 previous stereotactic vacuum-assisted biopsy procedures (p = 0.002). CONCLUSION: Stereotactic 11-gauge vacuum-assisted biopsy had a false-negative rate of 3.3% that diminished to 0.6% with experience. All false-negative findings could be prospectively identified because of failure to sample calcifications or imaging-histologic discordance.