剪切波弹性成像技术定量评价乳腺癌新辅助化疗疗效的价值

Accuracy of ultrasound shear-wave elastography in predicting pathologic response after neoadjuvant chemotherapy for breast cancer

目的探讨剪切波弹性成像（SWE）技术定量评价乳腺癌新辅助化疗疗效的价值。方法2012年10月至2013年6月解放军总医院经穿刺活检组织病理学确诊的原发性浸润性乳腺癌患者43例，共44个病灶。所有患者均接受规范化疗，并最终行外科手术切除。43例乳腺癌患者行新辅助化疗4-8个周期。应用SWE技术测量新辅助化疗前后乳腺癌最大弹性值的变化率。乳腺癌新辅助化疗疗效组织病理学评价标准采用Miller＆Payne分级。定义弹性值降低率≥30％为新辅助化疗有效[完全缓解（CR）＋部分缓解（PR）]；弹性值降低率〈30％为新辅助化疗无变化（SD）；定义弹性值增加为乳腺癌进展（PD）。CR＋PR对应病理反应显著（G3＋G4＋G5）；SD＋PD对应病理反应非显著（G1＋G2）。以手术组织病理学结果作为金标准，计算SWE技术评价乳腺癌新辅助化疗疗效的敏感度、特异度、准确性。采用Kappa检验分析SWE技术与组织病理学判断乳腺癌新辅助化疗疗效的一致性。采用配对样本t检验分别比较病理反应显著、病理反应非显著乳腺癌新辅助化疗前后最大弹性值差异；采用独立样本t检验分别比较新辅助化疗前、化疗后病理反应显著与病理反应非显著乳腺癌最大弹性值差异。结果根据Miller＆Payne分级，本组44个乳腺癌新辅助化疗后手术组织病理学结果为G1级3个，G2级6个，G3级24个，G4级8个，G5级3个，即病理反应显著35个，病理反应非显著9个；最大弹性值降低率〈30％共11个，最大弹性值降低率≥30％共33个，即无变化或进展（SD＋PD）11个，有效（CR＋PR）33个。SWE技术评价乳腺癌新辅助化疗疗效的敏感度为88．6％，特异度为77．8％，准确性为8613％。SWE技术与组织病理学评价乳腺癌新辅助化疗疗效的一致性较好，Kappa值为0．61。新辅助化疗前、化疗后病理反应显著与病理反应非显著乳腺癌最大弹性值差异均无统计学意义[（180．6±51．7）kPaw（144．2±66．1）kPa，t=1．431，P=0．338：（76．5±45．3）kPa坩（109．6±47．4）kPa，t=-1．372，P=0．189]；病理反应非显著乳腺癌新辅助化疗前后最大弹性值差异也无统计学意义[（144．2±66．1）kPaW（109．6±47．4）kPa，t=-3．353，P=0．028]，但病理反应显著乳腺癌新辅助化疗前后最大弹性值差异有统计学意义[（144．2±66．1）kPaVS（109．6±47．4）kPa，t=-3．353，P=0．028]。结论SWE技术分析新辅助化疗前后乳腺癌硬度变化方便、快捷，准确性较高，是间接评价乳腺癌新辅助化疗疗效的有效方法。

Objective To assess the value of using shear-wave elastography （SWE） to predict response of patients with breast cancer following neoadjuvant chemotherapy （NAC）. Methods Between Oct. 2012 to Jun. 2013, 43 patients with 44 invasive breast cancer tumors diagnosed by ultrasound guided core needle biopsy （CNB） were retrospectively reviewed. All the 43 patients underwent 4-8 periods of standard NAC and the rates of max stiffness values estimated by SWE was compared with histological findings. Pathologic response in breast cancer was classified into five grades according to Miller ＆ Payne histopathological grading system. The response of NAC was defined as effective （CR ＋ PR）, the reduction rate of max SWE value ≥ 30%; stable disease （SD）, the reduction rate of max SWE value 〈 30%; progressive disease （PD）, SWE value increase. CR ＋ PR correlated with the major pathologic response （G3 ＋ G4 ＋ G5）; SD ＋ PD correlated with the minor pathologic response （G1 q- G2）. The sensitivity, specificity and agreement rate of SWE value was determined by comparing with the final surgical hispathological results which was the gold standard. The agreement of NAC response between SWE and surgical hispathological results was measured using Kappa statistics. The difference of max SWE value between before and after NAC of both groups of major and minor pathologic response was measured using paired t tests. The difference of max SWE value before and after NAC was measured respectively between group of major and minor pathologic response using independence t tests. Results According to Miller＆ Payne histopathological grading system, pathological response of all the 44 breast tumors underwent NAC was： 3 G1, 6 02, 24 G3, 8 G4 and 3 G5 （35 major pathologic responses and 9 minor pathologic response）. The reduction rate of max SWE value 〈 30% （SD ＋ PD） was 11 in 44 cases and the reduction rate of max SWE value ≥30% （CR ± PR） was 33 in 44 cases. The SWE values of all the tumors decreased. The sensitivity, specificity and accordance rate of SWE to predict response to NAC was 88.6%, 77.8% and 86.3%. The agreement between SWE results and surgical excision findings was satisfied and Kappa value was 0.61. The max SWE value before and after NAC have no differences between groups of major and minor pathologic response [（180.6±51.7） kPa vs （144.2±66.1） kPa, t=1.431, P=0.338; （76.5±45.3） kPa vs （109.6±47.4） kPa, t=1.372, P=0.189] . There was also no difference between max SWE value before and after NAC of group of minor pathologic response E（144.2±66.1） kPa vs （109.6±47.4） kPa, t=3.353, P=0.028] . However, there was significant difference between max SWE value before and after NAC of group of major pathologic response [（180.6±51.7） kPa vs （76.5±45.3） kPa, t=-7.906, P=-0.000] . Conclusion SWE was a convenient, accurate methods in predicting responds to NAC in patients with breast cancer.