Stereotactic-guided Vacuum-assisted Breast Biopsy: Safety and Efficacy in the Asian Population

Full Article

AYH Wan, AYT Lai, SSW Lo, WWC Wong, JLS Khoo

Hong Kong J Radiol 2014;17:76-86

DOI: 10.12809/hkjr1413201

Objectives: Stereotactic-guided vacuum-assisted breast biopsy (VAB) has gained popularity as a minimally invasive technique for the evaluation of non-palpable breast lesions with microcalcifications. Percutaneous VAB device has been shown to have many advantages over conventional percutaneous biopsy methods and is also a recognised method for complete excision of benign breast lesions. However, analytical studies on the utility of VAB in Asian women are relatively rare, who often have smaller or thinner breasts than the western women. Therefore, the aim of this study was to evaluate the safety and efficacy of a 9-gauge VAB system performed in Asian patients in a conventional mammography unit of a regional hospital in Hong Kong.

Methods: A retrospective review of 41 consecutive patients who received stereotactic-guided VAB of microcalcifications between September 2008 and April 2013 in a regional hospital was conducted. Data on patients’ demographics, pre-procedural mammographic studies graded with reference to the Royal College of Radiologists Breast Group breast imaging classification, biopsy-related technical factors (including the type of needle applied, approach used, and marker deployment), technical success rate, associated complications, and pathological outcomes were evaluated.

Results: A total of 41 consecutive patients with 43 lesions were included in the study; two patients had bilateral lesions. The grading of the microcalcifications was as follows: 90.7% (n=39) as indeterminate, 7.0% (n=3) as suspicious of malignancy, and 2.3% (n=1) as highly suspicious of malignancy. The most common location (48.8%) of the microcalcifications was in the upper outer quadrant of the right breast. A needle aperture of 12 mm was used in 25.6% (n=11) of patients, and a needle aperture of 20 mm was employed in the remaining 74.4% (n=32). A lateral-medial approach was used in all but one case (97.7%, n=42); cranial-caudal approach was used in one patient (2.3%). Technical success rate was 100% with microcalcifications present in all post-biopsy specimen radiographs. None of the cases required a repeated biopsy. Most reported complications were minor and included vasovagal syncope (n=1), mild bleeding (n=5), clinically non-significant haematomas (n=3), mild bruising (n=4), and breast induration (n=1). All these were resolved spontaneously without any additional intervention. The VAB histology was benign in 62.8% (n=27) of the lesions; 37.2% (n=16) were malignant or malignancy-associated lesions. The benign microcalcifications were predominantly due to fibrocystic change (n=13) whereas the malignant or malignancy-associated lesions included invasive ductal carcinoma (n=1), ductal carcinoma in situ (n=7), atypical ductal hyperplasia (n=6), atypical lobular hyperplasia (n=1), and atypical columnar cell hyperplasia (n=1). In the majority of the VAB-diagnosed malignant or malignancy-associated lesions that were surgically excised (71.4%, n=5/7), there was concordance between VAB and postoperative histology. The overall underestimation rate was 5.9% (2/34). The underestimation rate for ductal carcinoma in-situ was 14.3% (1/7). Overall, there were seven true-positive cases, no false-positive case, 26 true-negative cases, and one false-negative case. The sensitivity for VAB was calculated to be 87.5%, while the specificity was 100%. The true-positive predictive value was 100% while the negative predictive value was 96.3%. There were 10 patients with previously treated malignant breast disease. Of these, a relatively high proportion (70%, n=7) showed recurrence of malignant or malignancy-associated pathology — one patient had recurrence at the same site while the remaining patients had recurrent disease in the contralateral breast.

Conclusion: Stereotactic-guided vacuum-assisted breast biopsy with a 9-gauge biopsy system is a safe and effective method for evaluation of non-palpable breast lesions with microcalcifications on mammography, and is the most reliable alternative to surgical breast biopsy. In particular, a lower threshold to utilise VAB for microcalcification in patients with prior breast disease should be used.






目的:作為一種評估臨床不能觸及並含微小鈣化灶的乳腺病變的微創技術,立體定位引導下真空輔助乳房活檢(VAB)已漸漸普及。與傳統的經皮活檢比較,經皮VAB技術有更多優點;其作為完全切除乳腺良性病變的技術也獲認可。亞洲女性的乳房一般比西方婦女較小、腺體亦較薄。VAB在亞洲女性中的效用分析研究相對較少。本研究旨在評估香港一所分區醫院中常規乳腺鉬靶攝影部利用9G VAB系統對亞洲患者進行活檢的安全性和有效性。

方法:回顧分析2008年9月至2013年4月期間在一所分區醫院因發現乳腺微小鈣化灶而接受立體定位引導下VAB 的共41名患者。評估指標包括:患者的人口統計學資料、術前乳腺鉬靶影像分級(依照英國皇家醫學院放射科醫師乳腺組制定的分級標準)、與活檢相關的技術因素(包括應用針的類型、使用方法和標記放置)、技術成功率、併發症和病理結果。