Liu Li-Heng, Zhou Guo-Feng, Lv Han, Wang Zhen-Chang, Rao Sheng-Xiang, Zeng Meng-Su
Department of Radiology, Zhongshan Hospital, Fudan University, No. 180 Fenglin Road, Shanghai, China.
Multi-Disciplinary Team of Colorectal Cancer, Zhongshan Hospital, Fudan University, Shanghai, China.
Eur Radiol. 2021 Aug;31(8):5640-5649. doi: 10.1007/s00330-020-07647-2. Epub 2021 Jan 15.
Response evaluation criteria in solid tumors (RECIST) often fail to identify clinically meaningful response to bevacizumab-containing therapy in colorectal liver metastasis (CRLM). This study aimed to develop RECIST by combining contrast-enhanced and diffusion-weighted magnetic resonance imaging (MRI).
A total of 126 patients with CRLM who underwent hepatic resection after bevacizumab-containing chemotherapy were split into initial analyses cohort (N = 42, with 76 indexed liver metastases) and validation cohort (N = 84). In lesion-based analyses, percentage decrease of arterial enhancement area and percentage increase of apparent diffusion coefficient (ADC) value from baseline to post-chemotherapy were measured. Their optimal cutoff values for distinguishing pathology-confirmed major and minor response were determined. Then, the developed RECIST (D-RECIST) was established by combining functional and size-based items. Survival relevance of D-RECIST and RECIST was examined in the validation cohort.
Percentage decrease of arterial enhancement area and increase of ADC value significantly differed between lesions of pathologic major or minor response, with optimal cutoffs of approximately 33% and 19%, respectively. Patients defined as responders by D-RECIST had a significantly longer median disease-free survival (DFS) than non-responders (p = 0.021; 12.9 versus 8.6 months). No significant difference was observed with RECIST (p = 0.524). In a Cox regression model, D-RECIST- but not RECIST-defined responses independently predicted the DFS (p = 0.034 and 0.811).
D-RECIST-defined responses provided significant prognostic information, and thus may serve as a better response evaluation approach than RECIST in CRLM treated with bevacizumab-containing therapy.
• Changes in arterial enhancement area and apparent diffusion coefficient value are associated with pathological response in colorectal liver metastases treated with bevacizumab. • The MRI-based response criteria developed by combining size-based and functional features can provide significant prognostic information.
实体瘤疗效评价标准（RECIST）常常无法识别结直肠癌肝转移（CRLM）患者接受含贝伐单抗治疗后的临床有意义的反应。本研究旨在通过结合对比增强和扩散加权磁共振成像（MRI）来制定RECIST。
共有126例接受含贝伐单抗化疗后行肝切除术的CRLM患者被分为初始分析队列（N = 42，有76个索引肝转移灶）和验证队列（N = 84）。在基于病灶的分析中，测量从基线到化疗后动脉强化面积的减少百分比和表观扩散系数（ADC）值的增加百分比。确定它们区分病理证实的主要和次要反应的最佳临界值。然后，通过结合基于功能和大小的指标建立了改良的RECIST（D-RECIST）。在验证队列中检查D-RECIST和RECIST与生存的相关性。
病理主要或次要反应的病灶之间，动脉强化面积的减少百分比和ADC值的增加有显著差异，最佳临界值分别约为33%和19%。被D-RECIST定义为有反应的患者的无病生存期（DFS）中位数显著长于无反应者（p = 0.021；12.9个月对8.6个月）。RECIST则未观察到显著差异（p = ．524）。在Cox回归模型中，D-RECIST定义的反应而非RECIST定义的反应独立预测DFS（p = 0.034和0.811）。
D-RECIST定义的反应提供了显著的预后信息，因此在接受含贝伐单抗治疗的CRLM中，可能是比RECIST更好的反应评估方法。
• 动脉强化面积和表观扩散系数值的变化与接受贝伐单抗治疗的结直肠癌肝转移的病理反应相关。• 通过结合基于大小和功能特征制定的基于MRI的反应标准可提供显著的预后信息。
