Stereotactic-guided Vacuum-assisted Breast Biopsy: Safety and Efficacy in the Asian Population
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.
中文摘要
立體定位引導真空輔助乳腺活檢：在亞洲人口中的安全性和有效性
尹宇瀚、黎爾德、盧成瑋、黃慧中、邱麗珊
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。
結果：連續41名患者的43個病灶被列入研究範圍；其中兩名患者有雙側病變。針對微小鈣化灶的分級如下：90.7%（39例）屬性質不定、7.0%（3例）屬可疑惡性、2.3%（1例）屬高度可疑惡性。微小鈣化灶的最常見位置是在右乳房上外象限（48.8%）。有25.6%的患者（11例）使用12毫米針芯，其餘74.4%（32例）則使用20毫米針芯。除1例外，所有病例均採用外內位（97.7%，42例）；餘下的1例（2.3%）則採用頭尾位。所有活檢標本X光片呈微小鈣化的徵象，技術成功率達100%。無病例需重複進行活檢。大多數併發症均屬輕微，包括血管迷走性暈厥（1例）、輕微出血（5例）、臨床輕微血腫（3例）、輕度挫傷（4例）和乳房硬結（1例）。所有併發症均自行緩解，無需額外干預治療。VAB組織學發現62.8%（27例）的乳腺病變為良性，另37.2%（16例）為惡性或與惡性腫瘤相關的病變。良性鈣化主要見於纖維囊性改變（13例），而惡性或與惡性相關的病變則包括浸潤性導管癌（1例）、乳腺導管原位癌（7例）、非典型性導管增生（6例）、非典型小葉增生（1例）和非典型柱狀細胞增生（1例）。按VAB診斷為惡性或與惡性相關病變多數經外科手術切除（5/7，71.4%），VAB與術後組織學之間呈一致性。整體低估率為5.9%（2/34）。原位導管癌的低估率為14.3%（1/7）。總體而言，真陽性病例有7個、假陽性病例有0個、真陰性病例有26個、假陰性病例有1個。所以VAB的敏感性為87.5%，特異性為100%。陽性預測值為100%，陰性預測值為96.3%。有10名患者以前曾經接受惡性乳腺疾病的治療，其中有較高的比例（7例，70%）顯示惡性復發或惡性病變相關的病理，1例為原位復發，其餘為對側乳腺復發。
結論：針對臨床不可觸及且鉬靶片上有微小鈣化灶的乳腺病變，利用9G真空探針進行立體定位引導下VAB是安全和有效的，亦是手術乳房活檢一個最可靠的替代法。尤其是對於之前有乳腺病變的患者，因微鈣化灶運用VAB的臨界標準應調低。