进展期胃癌NAC后胃癌周围脂肪组织双能CT碘含量的判断

Measuring iodine concentration in perigastric adipose tissue with DECT for judgment of serosa status in patients with advanced gastric cancer after NAC

目的:探讨双能量CT成像测量胃癌周围脂肪组织碘含量判断胃癌NAC后浆膜状况的价值。方法:分析34例T_4进展期胃癌患者NAC前、后双能量图像,根据术后病理分组,比较T降期组(n=10)与未降期组(n=24)胃癌周围脂肪组织碘含量(IC_(胃癌周脂肪))和标准化胃癌周围脂肪组织碘含量(IC_(标准化胃癌周脂肪)),采用ROC曲线法评价其判断NAC后浆膜受侵的能力。结果:与术后病理对照,传统CT判断NAC后浆膜状况的准确性为70.59%。降期组与未降期组NAC前、后IC_(胃癌周脂肪)的变化(△IC_(胃癌周脂肪))及IC_(标准化胃癌周脂肪)的变化(△IC_(标准化胃癌周脂肪))的差异有统计学意义(P均<0.05)。曲线下面积(AUC)为0.908,△IC_(标准化胃癌周脂肪)界值为0.095时,判断NAC后浆膜受侵的敏感性为90.0%,特异性为83.3%,准确性为85.29%。结论:IC_(标准化胃癌周脂肪)是一项可较准确判断NAC后浆膜状况、指导确定手术时机的有效指标。

Objective： To explore the value of measuring iodine concentration （IC） in perigastric adipose tissue with dualenergy CT （DECT） for judgment of serosa status after neoadjuvant chemotherapy （NAC）. Methods： Thirty-four patients with T, advanced gastric cancer who underwent DECT before and after treatment were enrolled. According to the postoperative pathologic results, the patients were divided into two groups： the down-staging group（n=10） and the non-down-staging group（n=24）. IC （ICPAT） and standardized IC （SICpAT） of perigastric adipose tissue were measured in the two groups, respectively. ROC curve was used to evaluate the capability of SICpAT in detecting serosa invasion. Results： Compared with postoperative pathologic resuits, the accuracy of judgment of serosa status was 70.59% by conventional CT after NAC. The differences of the changes of ICpAT （△ICPAT） and SICPAT （△SICpAT） between the two groups were statistically significant （P〈0.05）. With a △SICpAT threshold of 0.095, area under curve （AUC） was 0.908, the sensitivity, specificity and accuracy for detecting serosa invasion were 90.0%, 83.3% and 85.29%, respectively. Conclusion： The SICpAT in perigastric adipose tissue is an effective indicator to determine the serosa status after NAC and to guide the operation time.