经直肠超声在早期直肠癌诊断中应用初步探讨

Preliminary clinical experience of transrectal ultrasonography in early rectal cancer

目的总结TRUS对直肠癌浸润深度诊断准确性，分析探讨TRUS在早期直肠癌诊断中的应用。方法2002年1月至2007年10月163例直肠癌患者术前行TRUS检查，参考国际抗癌联盟有关直肠癌分期标准进行浸润深度分期诊断，并与手术病理结果对照。163例直肠癌中经病理检查证实16例为早期癌。研究病例术前均未接受放化疗。结果TRUS对早期直肠癌（pT1）诊断灵敏性为87．5％（14／16），特异性达98．6％（145／147），阳性预测值为87．5％（14／16）。对早期癌浸润深度进一步分析，TRUS对黏膜癌及黏膜下层癌诊断灵敏性分别为85．7％（6／7）、66．7％（6／9）。16例早期癌（pT1）经肛门注水充盈直肠后再次行TRUS检查，病变均显示清晰，14例正确诊断为pT1期；未充盈直肠的情况下，仅6例病变显示清晰，仅3例诊断正确。早期癌声像图表现分为二型：隆起型、溃疡型，以隆起型多见，占81．6％（13／16）。结论TRUS在早期直肠癌的诊断中是一项有价值的影像学方法，经肛门注水充盈直肠后，明显提高了早期癌病变显示率及诊断准确性。

Objective To evaluate the accuracy of transrectal uhrasonography （TRUS） in the assessment of the invasion depth of rectal cancer, and analyze the value of TRUS in diagnosis of early rectal cancer. Methods TRUS was performed preoperatively in 163 patients with rectal cancer, and the results was compared with the postoperative pathological findings according to TNM staging. The early rectal cancer was diagnosed if the lesion was limited to mucosa and submncosa. The tumor located in mucosa was defined as mucosal cancer, while as submucosal cancer when the tumor invading into submucosa. Sixteen cases were confirmed as early cancer by pathology after the operation. No patients received chemotherapy and radiotherapy before operation. Results The sensitivity of TRUS in the staging of the early rectal cancer was 87. 5% （14/16）, specificity was 98.6% （145/147）, and the positive predictive value was 87.5% （14/16）. The sensitivity of TRUS in predicting mucosal and submueosal cancer was 85.7% （ 6/7 ） and 66.7% （6/9）, respectively. Sixteen patients with early rectal cancer were examined before and after filling rectum with water. After filling rectum, all tumors were visualized clearly, while 14 tumors were correctly diagnosed as early rectal cancer. Before filling rectum, only 6 tumors were visualized clearly, and 3 tuomrs were staged correctly. The ultrasonographic appearance of early rectal cancer manifested in two kinds： protruded and ulcerative, and most were protruded （81.6%）. Conclusions TRUS is a valuable imaging examination for diagnosis of early rectal cancer preoperatively. Visualization rate and diagnostic accuracy of early rectal cancer are improved dramatically after filling rectum with water.