直肠腔内超声在直肠癌术前分期的应用价值

Value of Endorectal Ultrasonography in Preoperative Staging of Rectal Cancer

目的评价直肠腔内超声(ERUS)对直肠癌术前分期诊断的准确性以及探讨影响ERUS分期诊断准确性的因素。方法对我院2008年9月至2009年11月期间94例直肠癌患者术前行ERUS检查,观察肿块大小、形态、回声、位置、浸润深度及邻近组织脏器受累情况。参考TNM分期标准进行术前分期诊断,并与术后病理结果对照。结果 ERUS诊断94例直肠癌浸润深度的总准确性为63.8%(60/94),术后病理分期pT1、pT2、pT3及pT4各期的诊断准确性分别为87.2%(82/94)、76.6%(72/94)、76.6%(72/94)及97.9%(92/94)。ERUS对进展期直肠癌(pT3+pT4)的诊断敏感性、特异性及准确性分别为70.8%(34/48)、78.3%(36/46)及74.5%(70/94)。对94例直肠癌淋巴结转移的诊断敏感性、特异性及准确性分别为75.0%(42/56)、42.1%(16/38)及61.7%(58/94)。对不同位置的直肠癌浸润深度的诊断准确性差异无统计学意义(P=0.495)。对浸润深度分期准确性随检查者经验的丰富而提高,完成94例直肠癌检查后,对浸润深度的诊断准确性由早期的40.0%提高到了81.3%(P=0.026)。结论 ERUS对直肠癌浸润深度及转移淋巴结的诊断准确性较高,可作为直肠癌术前分期诊断的可靠手段。

Objective To determine the accuracy of endorectal ultrasonography （ERUS） in preoperative staging of rectal cancer and investigate the limitations and pitfalls of ERUS. Methods Ninety-four patients with rectal cancer were examined preoperatively by ERUS between September 2008 and November 2009 in this hospital. The size,shape,echo pattern,infiltration depth,and extra-rectal invasion of lesions were observed. The results of ERUS staging were compared with histopathology findings of the resected specimens. Results The overall accuracy of ERUS in T staging was 63.8% （60/94）. The accuracies of ERUS for pT1,pT2,pT3,and pT4 tumor were 87.2% （82/94）,76.6% （72/94）,76.6% （72/94）,and 97.9% （92/94）,respectively. The sensitivity,specificity,and accuracy of ERUS for advanced rectal cancer （pT3＋pT4） were 70.8% （34/48）,78.3% （36/46）,and 74.5% （70/94）,respectively. The sensitivity,specificity,and accuracy of ERUS in lymph node metastasis were 75.0% （42/56）,42.1% （16/38）,and 61.7% （58/94）,respectively. There was no significant difference of accuracy among various tumor locations above anocutaneous line （P=0.495）. The accuracy of ERUS for T staging improved with experience,the T staging accuracy improved from 40.0% after assessment of 30 cases to 81.3% after 94 cases were examined （P=0.026）. Conclusions The ERUS provides a good accuracy rate for assessment of the depth of tumor invasion and lymph node metastasis of rectal cancer,and has become an important imaging tool for preoperative staging rectal cancer. The operator experience,peritumoral inflammation mainly influences the accuracy of ERUS.