多层螺旋CT在直肠癌术前分期中的诊断价值

背景与目的:直肠癌术前分期对选择合理治疗方案和判断预后至关重要。传统的计算机断层扫描(computed tomography,CT)对直肠癌术前分期存在争议,本研究旨在探讨多层螺旋CT(multislice spiral CT,MSCT)对直肠癌术前分期的诊断价值。方法:中山大学肿瘤防治中心2006年3月至2007年2月,经病理证实的直肠癌患者87例,所有患者术前行MSCT平扫及增强扫描,由两位放射科医生独立评价肿瘤的部位、大小、侵犯范围(T)、淋巴结转移(N)及远处转移(M)情况,做出诊断及TNM分期,并与术后病理对照,评价准确性、灵敏度及特异度。结果:MSCT检出了全部87例直肠癌,对直肠癌TNM分期总的准确性为81.6%(71/87)。T、N、M期准确性分别为94.3%(82/87)、82.8%(72/87)、98.9%(86/87)。≤T2、T3、T4期灵敏度分别为90.5%、91.3%、97.7%,特异度分别为98.5%、94.2%、97.7%。N0、N1、N2期灵敏度分别为92.9%、72.0%、82.4%,特异度分别为88.9%、88.5%、91.7%。远处转移的患者仅1例因肝脏转移灶<5mm而漏诊。结论:MSCT能较准确地判断直肠癌的侵犯范围、淋巴结转移及远处转移,是非常有价值的术前分期方法。

Value of multislice spiral CT in preoperative staging of rectal carcinoma

BACKGROUND & OBJECTIVE: Preoperative staging is important for optimal therapy planning and prognosis prediction of rectal carcinoma. The role of conventional computed tomography (CT) in preoperative staging of rectal carcinoma is controversial. This study was to evaluate the value of multislice spiral computed tomography (MSCT) in preoperative staging of rectal carcinoma. METHODS: From Mar. 2006 to Feb. 2007, 87 patients with pathologically proved rectal cancer underwent preoperative plain and enhanced MSCT. Two radiologists evaluated independently tumor location, size, the depth of tumor invasion into the rectal wall (T), the involvement of regional lymph nodes (N) and the presence of distant metastases (M) on CT images. TNM staging was made according to CT findings and compared with the pathologic results. The accuracy, sensitivity, and specificity were assessed. RESULTS: All the 87 cases of rectal carcinoma were detected clearly by MSCT. The accuracy was 81.6% for TNM staging, 94.3% for T staging, 82.8% for N staging, and 98.9% for M staging. The sensitivity was 90.5% for T1-2 staging, 91.3% for T3 staging, and 97.7% for T4 staging. The specificity was 98.5% for T1-2 staging, 94.2% for T3 staging, and 97.7% for T4 staging. The sensitivity was 92.9% for N0 staging, 72.0% for N1 staging, and 82.4% for N2 staging. The specificity was 88.9% for N0 staging, 88.5% for N1 staging, and 91.7% for N2 staging. Only 1 case of distant metastasis was missed due to the liver lesion of less than 5 mm. CONCLUSION: MSCT is an accurate technique for preoperative staging of rectal carcinoma, which can assess the extension to adjacent tissues and the presence of lymph node and distant metastases exactly.