From the Department of Oncology, Akershus University Hospital, Epigen, Akershus Universitetssykehus HF, 1478 Lørenskog, Norway (K.M.B., S.M., K.I.G., A.H.R., K.R.R.); Department of Physics (K.M.B., A.B.) and Institute of Clinical Medicine (A.N., A.H.R.), University of Oslo, Oslo, Norway; Department of Diagnostic Physics, Division of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway (E.G., A.B.); Department of Optometry, Radiography and Lighting Design, University of South-Eastern Norway, Drammen, Norway (E.G.); Department of Radiology, Akershus University Hospital, Lørenskog, Norway (A.N., S.H.H.); Sunnmøre MR-Klinikk, Ålesund, Norway (K.I.G.); and Department of Physics, Norwegian University of Science and Technology, Trondheim, Norway (K.R.R.).
Radiology. 2020 Nov;297(2):352-360. doi: 10.1148/radiol.2020200287. Epub 2020 Sep 1.
Background MRI is the standard tool for rectal cancer staging. However, more precise diagnostic tests that can assess biologic tumor features decisive for treatment outcome are necessary. Tumor perfusion and hypoxia are two important features; however, no reference methods that measure these exist in clinical use. Purpose To assess the potential predictive and prognostic value of MRI-assessed rectal cancer perfusion, as a surrogate measure of hypoxia, for local treatment response and survival. Materials and Methods In this prospective observational cohort study, 94 study participants were enrolled from October 2013 to December 2017 (ClinicalTrials.gov: NCT01816607). Participants had histologically confirmed rectal cancer and underwent routine diagnostic MRI, an extended diffusion-weighted sequence, and a multiecho dynamic contrast agent-based sequence. Predictive and prognostic values of dynamic contrast-enhanced, dynamic susceptibility contrast (DSC), and intravoxel incoherent motion MRI were investigated with response to neoadjuvant treatment, progression-free survival, and overall survival as end points. Secondary objectives investigated potential sex differences in MRI parameters and relationship with lymph node stage. Statistical methods used were Cox regression, Student test, and Mann-Whitney test. Results A total of 94 study participants (mean age, 64 years ± 11 [standard deviation]; 61 men) were evaluated. Baseline tumor blood flow from DSC MRI was lower in patients who had poor local tumor response to neoadjuvant treatment (96 mL/min/100 g ± 33 for ypT2-4, 120 mL/min/100 g ± 21 for ypT0-1; = .01), shorter progression-free survival (hazard ratio = 0.97; 95% confidence interval: 0.96, 0.98; < .001), and shorter overall survival (hazard ratio = 0.98; 95% confidence interval: 0.98, 0.99; < .001). Women had higher blood flow (125 mL/min/100 g ± 27) than men (74 mL/min/100 g ± 26, < .001) at stage 4. Volume transfer constant and plasma volume from dynamic contrast-enhanced MRI as well as Δ* peak and area under the curve for 30 and 60 seconds from DSC MRI were associated with local malignant lymph nodes (pN status). Median area under the curve for 30 seconds was 0.09 arbitrary units (au) ± 0.03 for pN1-2 and 0.19 au ± 0.12 for pN0 ( = .001). Conclusion Low tumor blood flow from dynamic susceptibility contrast MRI was associated with poor treatment response in study participants with rectal cancer. © RSNA, 2020
背景 磁共振成像（MRI）是直肠癌分期的标准工具。然而，需要更精确的诊断测试来评估对治疗结果具有决定性的肿瘤生物学特征。肿瘤灌注和缺氧是两个重要的特征，但目前尚无临床应用的可测量这些特征的参考方法。目的 评估 MRI 评估的直肠癌灌注作为缺氧替代指标对局部治疗反应和生存的潜在预测和预后价值。材料与方法 本前瞻性观察队列研究共纳入 94 例 2013 年 10 月至 2017 年 12 月期间经组织学证实的直肠癌患者（ClinicalTrials.gov 注册号：NCT01816607）。所有患者均行常规诊断性 MRI、扩展弥散加权序列和多回波动态对比剂增强序列检查。采用新辅助治疗反应、无进展生存期和总生存期作为终点，评估动态对比增强、动态磁敏感对比（DSC）和体素内不相干运动 MRI 的预测和预后价值。次要目标是研究 MRI 参数与淋巴结分期的潜在性别差异及其相关性。统计方法采用 Cox 回归、Student t 检验和 Mann-Whitney U 检验。结果 共评估了 94 例研究参与者（平均年龄 64 岁±11[标准差]；61 例男性）。DSC MRI 基线肿瘤血流在新辅助治疗局部肿瘤反应不良的患者中较低（ypT2-4 为 96 mL/min/100 g±33，ypT0-1 为 120 mL/min/100 g±21；P=.01），无进展生存期更短（风险比=0.97；95%置信区间：0.96，0.98；P<.001），总生存期更短（风险比=0.98；95%置信区间：0.98，0.99；P<.001）。与男性（74 mL/min/100 g±26）相比，女性（125 mL/min/100 g±27）在 4 期的血流更高（P<.001）。动态对比增强 MRI 的容积转移常数和血浆容量以及 DSC MRI 的 30 秒和 60 秒的Δ*峰值和曲线下面积与局部恶性淋巴结（pN 状态）有关。30 秒曲线下面积的中位数为 0.09 个任意单位（au）±0.03（pN1-2）和 0.19 au±0.12（pN0）（P=.001）。结论 在直肠癌患者中，DSC MRI 肿瘤血流低与治疗反应不良有关。
