多排CT对早期胃癌术前评估的价值

The significance of multidetector-row computed tomography in the preoperative evaluation of early gastric carcinoma

目的:探讨多排CT(multidetector-row computed tomography,MDCT)对早期胃癌术前评估的价值。方法:对725例胃癌病人(包括115例早期胃癌)术前行MDCT检查,并将其结果与病理检查结果相对照。结果:MDCT对早期和进展期胃癌的检出率分别为74.8%(86/115)和99.0%(604/610),二者间存在显著差异(P=0.000)。MDCT检出的早期胃癌瘤体明显大于未被检出者(2.8cm比1.6cm,P=0.000),并且其淋巴结转移率显著高于后者(20.9%比3.4%,P=0.040)。MDCT鉴别早期和进展期胃癌的总准确率达94.2%(683/725)。在86例MDCT检出原发灶的早期胃癌病人中,59例得到准确分期,而其余27例均被过度分期为T2或T3期,两组在大体类型(P=0.007)和分层方式(P=0.000)间存在显著差异;多因素分析显示仅分层方式与MDCT对早期胃癌T分期的判断准确率相关。MDCT对早期胃癌淋巴结转移判断的敏感度、特异度和准确率分别为73.7%(14/19)、85.4%(82/96)和83.5%(96/115);对<4枚转移淋巴结的判断敏感度为66.7%(10/15),对≥4枚者的敏感度达100.0%(4/4)。在MDCT未检出转移淋巴结的5例早期胃癌病人中,其肿瘤均≥2cm,2例属凹陷型黏膜内癌。1例早期胃癌兼有位于左肝内<1cm的转移灶未被MDCT检出,其余114例早期胃癌均被准确判断为M0期。结论:MDCT对早期胃癌术前评估的临床应用价值较大,对于被MDCT检出原发灶的早期胃癌病人,由于其淋巴结转移率高且肿瘤较大,不宜行微创治疗。此外,由于多数早期胃癌病人的转移淋巴结少于4枚,且MDCT对其判断的敏感度相对较低,所以在考虑对早期胃癌病人行微创治疗时,仍应高度重视淋巴结转移之相关临床病理因素对淋巴结状况评估的作用。

Objective To investigate the significance of muhidetector-row computed tomography （MDCT） in the preoperative evaluation of early gastric carcinoma （EGC）. Methods A total of 725 gastric carcinoma patients （including 115 patients with EGC） underwent preoperative MDCT examination. The results of MDCT were compared with corresponding pathological findings. Results The detection rate of primary tumor by MDCT was 74.8% （86/115） for EGC, and 99.2% （604/610） for advanced gastric carcinoma （AGC）, respectively; there existed a significant difference （P=0.000）. The tumor size of EGC patients whose primary tumor was detected by MDCT was larger than that of patients whose tumor was not detected by the same means（2.8 cm vs. 1.6 cm, P=0.000）. Moreover, the incidence of lymph node（LN） metastasis in the former group was higher than that in the latter （20.9% vs. 3.5%, P=0.040）. The accuracy of MDCT in differentiating EGC from AGC was 94.2% （683/725）. Among those 86 EGC patients whose primary tumor was detected by MDCT, 59 cases were correctly staged, while the remaining 27 patients were overstaged as T2 or T3. There existed a significant difference between the two groups in terms of macroscopic typing （P=0.007） and layered pattern （P=0.000）. Multivariate analysis by logistic regression showed that only layered pattern was closely related to the accuracy of MDCT in determining the T staging of EGC. The diagnostic sensitivity, specificity and accuracy of MDCT for determining LN metastasis of EGC were 73.7% （14/19）, 85.4% （82/96）, and 83.5% （96/115）, respectively. The diagnostic sensitivity of MDCT for determining LN metastasis was 66.7% （10/15） in EGC patients with 〈4 metastatic LNs, while it was 100.0% （4/ 4） in those with 〉14 metastatic LNs. In 5 EGC cases of LN metastasis not detected by MDCT, their tumor sizes were all ≥ 2 cm; and in 2 of the cases belonging to mucosal carcinomas, both were of the depressed types. In one EGC patient, a solitary metastasis smaller than 1 cm in the left liver was undetected by MDCT, while all the remaining 114 EGC patients were correctly staged as M0. Conclusions The clinical value of MDCT in the preoperative assessment of EGC is relatively high. Patients whose primary tumor has been detected by MDCT may be unfit to undergo minimally invasive therapy because of their higher incidence of LN metastasis and larger primary tumor size. In addition, because the diagnostic sensitivity of MDCT in determining LN metastasis is relatively low in patients with less than 4 metastatic LNs, the pay greater attention to LN metastasis-associated clinicopathological parameters in predicting the LN status shoud be pa, especially when minimally invasive therapy is being considered for these patients.