Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio", Chieti, Italy.
ITAB Institute of Advanced Biomedical Technologies, University "G. d'Annunzio", Via Luigi Polacchi, 11 66100, Chieti, Italy.
Abdom Radiol (NY). 2018 Sep;43(9):2221-2230. doi: 10.1007/s00261-018-1457-8.
The purpose of the article is to determine whether changes in apparent diffusion coefficient (ADC) values of locally advanced rectal cancer (LARC) obtained 2 weeks after the beginning of chemoradiation therapy (CRT) allow to predict treatment response and whether correlate with tumor histopathologic response.
Forty-three patients receiving CRT for LARC and 3.0T magnetic resonance imaging with diffusion-weighted sequences before treatment, 2 weeks during, and 8 weeks post the completion of CRT were included. ADC values were calculated at each time point and percentage of ADC changes at 2 weeks (ΔADC during) and 8 weeks (ΔADC post) were assessed. Data were correlated to surgical results and histopathologic tumor regression grade (TRG), according to Mandard's classification. ADC values and ΔADCs of complete responders (CR; TRG1) and non-complete responders (non-CR; TRG 2-5) were compared. Receiver-operating characteristic curve (ROC) analysis was used to assess diagnostic accuracy of ΔADC for differentiating CR from non-CR. The correlation with TRG was investigated using Spearman's rank test.
ΔADC during and ΔADC post were significantly higher in CR (33.9% and 57%, respectively) compared to non-CR (13.5% and 2.2%, respectively) group (p = 0.006 and p < 0.001, respectively). ROC analysis revealed the following diagnostic performances: ΔADC during: AUC 0.78 (0.08), p = 0.004, cut-off 20.6% (sensitivity 75% and specificity 76.5%); ΔADC post: AUC 0.94 (0.04), p ≤ 0.001, cut-off 22% (sensitivity 95% and specificity 82.4%). Significant moderate and good negative correlation was found between ΔADC during and ΔADC post and TRG (r = - 0.418, p = 0.007; r = - 694, p ≤ 0.001, respectively).
ΔADC at 2 weeks after the beginning of CRT is a reliable tool to early assess treatment response.
本文旨在确定局部晚期直肠癌（LARC）患者在接受放化疗（CRT）2 周后，表观扩散系数（ADC）值的变化是否能够预测治疗反应，以及与肿瘤组织病理学反应是否相关。
本研究共纳入 43 例接受 CRT 治疗的 LARC 患者，所有患者在治疗前、治疗 2 周时和治疗结束后 8 周时均接受 3.0T 磁共振成像扩散加权序列检查。在每个时间点计算 ADC 值，并评估治疗 2 周时（ΔADC 期间）和 8 周时（ΔADC 后）的 ADC 变化百分比。根据 Mandard 分类，将数据与手术结果和肿瘤组织学消退分级（TRG）相关联。比较完全缓解（CR；TRG1）和非完全缓解（非-CR；TRG 2-5）患者的 ADC 值和 ΔADC。采用受试者工作特征曲线（ROC）分析评估 ΔADC 对区分 CR 和非-CR 的诊断准确性。采用 Spearman 等级相关检验分析与 TRG 的相关性。
CR 组的ΔADC 期间（33.9%）和 ΔADC 后（57%）显著高于非-CR 组（分别为 13.5%和 2.2%）（p=0.006 和 p<0.001）。ROC 分析显示以下诊断性能：ΔADC 期间：AUC 为 0.78（0.08），p=0.004，截断值为 20.6%（敏感性 75%，特异性 76.5%）；ΔADC 后：AUC 为 0.94（0.04），p≤0.001，截断值为 22%（敏感性 95%，特异性 82.4%）。ΔADC 期间和 ΔADC 后与 TRG 之间存在显著中度和良好的负相关（r=-0.418，p=0.007；r=-694，p≤0.001）。
CRT 开始后 2 周时的 ΔADC 是评估治疗反应的可靠工具。
