Stereotactic-guided Biopsy of Mammographic Microcalcifications: When Shall We Use Digital Add-on Unit Instead of Prone Table Machine?
CY Lee, WS Wan, CY Lui
Hong Kong J Radiol 2014;17:152-61
DOI: 10.12809/hkjr1413224
Objective: To identify mammographic features for cases in which stereotactic-guided biopsy for breast microcalcifications failed on a prone table machine but were successful with a digital add-on unit.
Methods: Stereotactic-guided biopsies performed with a digital add-on unit after failure on a prone table machine between 1 January 2009 and 30 June 2013 and consecutive stereotactic-guided biopsies performed on prone table machine from 1 January 2012 to 31 March 2012 as controls were retrieved. The electronic patient records, preprocedural mammograms, stereotactic data, radiology reports, specimen characteristics, and histology of these cases were studied and the mammographic features were reviewed. Comparisons between the two groups were made using Chi-square test and independent T-test.
Results: A total of 54 cases performed with a digital add-on unit (mean age, 50 years) and 101 cases performed on a prone table machine (mean age, 53 years) were included. All patients were females. Five mammographic features were significantly (p < 0.05) associated with successful retrieval of calcification in stereotactic-guided biopsies performed with a digital add-on unit versus that on a prone table machine. These included (1) distance of microcalcification clusters from pectoralis muscle of <15 mm (35% vs. 20%), (2) size of the microcalcification clusters of ≤5 mm (57% vs. 34%), (3) number of microcalcifications of <10 (43% vs. 24%), (4) predominant microcalcification morphology of intermediate or suspicious nature (74% vs. 44%), and (5) faint density of microcalcifications (63% vs. 29%). Breast density did not demonstrate any statistically significant difference in the two groups. Similar results were obtained on comparing the two groups after only including cases with visible calcification in pathological specimens. Indication of biopsy, radiological grading, technical details, and histological outcomes showed no statistically significant difference between the two groups.
Conclusion: In centres where both machines are available, performing stereotactic-guided biopsy directly with a digital add-on unit should be considered for cases which demonstrate any of the five specific mammographic features described above. Further randomised trials are warranted to confirm the significance of the identified characteristics.
中文摘要
乳腺微鈣化的立體定位穿刺活檢：何時使用數碼式附加組件來代替俯臥式立體定位切片機？
李芷茵、溫詠雪、呂振英
目的：探討立體定位穿刺活檢乳腺微鈣化點時，俯臥式立體定位切片機檢測失敗而在數碼式附加組件上成功檢測的病例的乳腺X線片特徵。
方法：兩組接受立體定位穿刺活檢的病人被納入本研究，其中一組於2009年1月1日至2013年6月30日期間未能在俯臥式立體定位切片機，而只有在數碼式附加組件上成功進行活檢的病人。另一組則於2012年1月1日至2012年3月31日期間所有在俯臥式立體定位切片機上成功活檢的病人。研究比較兩組病人以下的資料：電子病歷、檢測前乳房X光片、立體定向數據、放射學報告、標本特點和病例的組織學；並回顧她們的乳腺X線片特徵。採用卡方檢驗和獨立樣本T檢驗進行組間比較。
結果：使用數碼式附加組件的有54例，病人的平均年齡為50歲；而使用俯臥式立體定位切片機的有101例，病人的平均年齡為53歲。所有患者均為女性。比較數碼式附加組件和俯臥式立體定位切片機兩種方式，有五個乳腺X線片特徵與成功取樣鈣化點顯著相關（p < 0.05），它們分別是：微鈣化簇與胸大肌的距離少於15毫米（35%比20%）、微鈣化簇為5毫米或以下（57%比34%）、微鈣化數量少於10（43%比24%）、中度或疑似惡性性質的以微鈣化為主的形態學（74%比44%），以及微鈣化密度低而模糊（63%比29%）。兩組的乳房密度並無任何統計學顯著差異。如果只將病理標本中可見鈣化點的病例納入研究範圍，兩組之間的比較亦得到相似的結果，即活檢指徵、放射學分級、技術細節和組織學結果均無統計學的顯著差異。
結論：如果中心同時有俯臥式立體定位切片機和數碼式附加組件，而病例乳腺X線片上出現上述五項特徵的其中任何一項時，便應考慮使用數碼式附加組件進行立體定位穿刺活檢。須進行更多研究來確認這些特徵的重要性。