直肠腔内超声在直肠癌术前环周切缘评估中的作用

Value of Endorectal Ultrasound in Preoperative Prediction of Circumferential Resection Margin of Rectal Cancer

目的评估直肠腔内超声(endorectal ultrasound,ERUS)诊断直肠癌环周切缘(circumferential resection margin,CRM)的可行性和准确性。方法回顾性分析2010年5月至2013年12月在北京协和医院行术前ERUS评估的直肠癌患者120例。纳入患者仅采用直肠全系膜切除术切除肿瘤,未采用术前新辅助放化疗治疗。患者行术前ERUS检查时测量CRM,即肿瘤的最外缘与直肠系膜筋膜的最短距离。以病理结果为金标准,比较不同CRM诊断标准下ERUS的诊断价值。分析ERUS对不同位置、距肛缘距离、分期的CRM诊断准确性差异。结果 ERUS可以显示直肠系膜筋膜114例,显示率为95%。采用不同探头频率,直肠系膜筋膜显示的差异存在统计学意义(P=0.034)。以CRM≤2 mm为标准时,ERUS诊断CRM的敏感性、准确性、阴性预测值最高,分别为100%、98.2%、100%。ERUS对不同位置、距肛缘距离、病理分期病灶的诊断准确性差异不具有统计学意义(P>0.05)。结论 ERUS可以准确诊断直肠癌环周切缘,同时具有较高的阴性预测值,可为判断预后及制定临床治疗方案提供可靠依据。

Objective To evaluate the feasibility and accuracy of endorectal ultrasound （ERUS） in pre- dicting the circumferential resection margin （CRM） of rectal cancer. Methods Between May 2010 and Decem- ber 2013, 120 patients with rectal cancer preoperatively evaluated with ERUS in Peking Union Medical College Hospital were retrospectively analyzed. The patients underwent total mesorectal excision without neoadjuvant che- moradiotherapy. CRM was measured with preoperative ERUS, i.e. the shortest distance between the outer edge of tumor and the mesorectal fascia. With pathological results as gold standard, the diagnostic values of ERUS un- der different criteria for CRM were assessed. The diagnostic accuracies of ERUS in predicting CRM among differ- ent positions, distances from the anal verge, and stages were analyzed. Results ERUS showed mesorectal fascia in 114 cases （95%）. The display rates of mesorectal fascia by ERUS with different transducer frequencies were significantly different （P = 0. 034）. With CRM ~〈2 mm as the standard, the sensitivity, accuracy and negative predictive value of ERUS in predicting CRM were the highest （ 100%, 98.2%, 100% ）. The diagnostic accura- cies of ERUS among different positions, distances from the anal verge, and stages were not significantly different （ P 〉 0. 05 ）. Conclusion ERUS can accurately predict CRM, with a high negative predictive value, which can provide reliable information for assessment of prognosis and formulation of clinical treatment plan.