Contrast-enhanced MRI for T Restaging of Locally Advanced Rectal Cancer Following Neoadjuvant Chemotherapy and Radiation Therapy
Contrast-enhanced MRI for T Restaging of Locally Advanced Rectal Cancer Following Neoadjuvant Chemotherapy and Radiation Therapy
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对比增强 MRI 用于新辅助化疗和放疗后局部晚期直肠癌 T 再分期
DOI：
10.1148/radiol.212905
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发表时间：
2022
期刊：
影响因子：
19.7
通讯作者：
Ying-Shi Sun
中科院分区：
文献类型：
--
作者：
Qiao-Yuan Lu;Zhen Guan;Xiao-Yan Zhang;Xiao-Ting Li;Rui-Jia Sun;Qing-Yang Li;Ying-Shi Sun
在新辅助化疗和放射治疗(NCRT)后，准确的直肠癌再分期是选择局部切除的关键。常规的T2加权成像和扩散加权成像(DWI)相结合的方法在诊断直肠癌NCRT后的病理分期方面具有局限性。目的通过与T2加权成像和弥散加权成像(DWI)的比较，探讨增强MRI对NCRT后直肠癌病理分期ypT0-1和ypT2-4的诊断价值。以手术病理标本作为参考标准。材料与方法本研究对北京大学肿瘤医院(北京，北京，中国)2014年1月至2018年10月。所有在NCRT前后获得的MRI特征都由两位经验丰富的放射科医生独立评估，对个人、临床和组织病理学信息视而不见。NCRT后YT分期根据第一轮T2加权成像(方案1)和第二轮对比度增强MRI扫描(方案2)的高值(b=1000秒/mm2)DWI进行分配。比较两种方案在区分肿瘤病理分期ypT0-1和ypT2-4方面的准确性。结果共纳入328例患者(平均年龄57岁±10岁；男性227例，占69%)。MRI增强扫描方案预测T0-1肿瘤病理分期的受试者工作特征曲线下面积为0.81(95%CI：0.77，0.85)，优于T2加权DWI方案(0.66；95%CI：0.60，0.71；P<；.001)。多变量Logistic回归分析显示，MRI增强扫描NCRT后的YT分期是唯一独立预测肿瘤病理分期的因素(P<；结论MRI增强扫描能准确区分新辅助化疗和放疗后的ypT0-1和ypT2-4肿瘤。
BackgroundAccurate restaging of rectal cancer is crucial in the selection of candidates for local excision after neoadjuvant chemotherapy and radiation therapy (NCRT). The conventional approach of combined T2-weighted imaging and diffusion-weighted imaging (DWI) at MRI has been found to have limitations in restaging.PurposeTo determine the diagnostic performance of contrast-enhanced MRI in distinguishing between pathologic stage ypT0–1 and ypT2–4 rectal cancer after NCRT compared with T2-weighted imaging and DWI by using surgical pathologic specimens as the reference standard.Materials and MethodsThis retrospective study evaluated MRI scans in all consecutive patients with locally advanced rectal cancer who underwent total mesorectal excision after NCRT in Peking University Cancer Hospital (Beijing, China) from January 2014 to October 2018. All MRI features obtained before and after NCRT were evaluated by two experienced radiologists, independently and blinded to personal, clinical, and histopathologic information. The post-NCRT yT stage was assigned based on highbvalue (b= 1000 sec/mm2) DWI with T2-weighted imaging (protocol 1) in the first round and on contrast-enhanced MRI scans (protocol 2) in a second round. The diagnostic accuracies for the differentiation of pathologic stage ypT0–1 from ypT2–4 tumors with the two protocols were compared. Multivariable regression analysis was used to explore the independent predictors of pathologic stage ypT0–1 tumors.ResultsA total of 328 patients (mean age, 57 years ± 10 [SD]; 227 men; 69%) were enrolled. The area under the receiver operating characteristic curve of the contrast-enhanced MRI protocol in predicting pathologic stage ypT0–1 tumors was 0.81 (95% CI: 0.77, 0.85), which was better than that of the T2-weighted DWI protocol (0.66; 95% CI: 0.60, 0.71;P< .001). Multivariable logistic regression analysis showed that yT stage after NCRT on contrast-enhanced MRI scans was the only independent predictor of pathologic stage ypT0–1 tumors (P< .001).ConclusionContrast-enhanced MRI provides accurate differentiation of ypT0–1 from ypT2–4 tumors after neoadjuvant chemotherapy and radiation therapy.© RSNA, 2022See also the editorial by Zins and Santiago in this issue.