Departments of Radiology (A.M.A., D.S., C.M.B., M.M.M., A.D.S., D.E.M.) and Biostatistics (Y.L.), University of Alabama at Birmingham, 619 19th St S, JTN 338, Birmingham, AL 35294-2172.
Radiol Imaging Cancer. 2020 Jul 17;2(4):e190074. doi: 10.1148/rycan.2020190074. eCollection 2020 Jul.
To investigate the prognostic value of differential enhancement on baseline dual-energy CT images in patients with treatment-naive pancreatic ductal adenocarcinoma (PDAC), with a focus on tumor-host interface characterization.
This was a retrospective, institutional review board-approved, Health Insurance Portability and Accountability Act-compliant study of 158 consecutive adult patients (mean age, 68 years; age range, 40.9-88.9 years; 50% women) with histopathologically proven, treatment-naive PDAC, who had undergone multiphasic pancreatic dual-energy CT from December 2011 to March 2017. Regions of interest in tumor core, tumor border, pancreas border with tumor, nontumoral pancreas, and aorta were recorded on pancreatic parenchymal phase (PPP) dual-energy CT 70-keV, 52-keV, and iodine material density (MD) images, plus portal venous phase (PVP) conventional CT images. Enhancement gradient (delta) across the tumor-pancreas interface was calculated. Delta was evaluated combining the dual-energy CT values with the PVP values and as individual predictors. Receiver operating characteristic analysis with logistic regression was used to determine the optimal cut point for each dual-energy CT delta to predict disease outcome based on highest Youden index. Survival curves were generated using Kaplan-Meier method, and comparison between two independent groups (high and low delta) was evaluated with log-rank test. Clinical outcomes included overall survival and distant metastasis-free survival. Three independent blinded radiologists visually scored tumor conspicuity (subjective delta score) on a 1-5 scale, and agreement was evaluated with κ statistic.
Ninety-three patients had advanced stage (50 locally advanced and 43 metastatic) and 65 had lower stage (48 resectable and 17 borderline resectable) tumors. Patients with high delta tumors (≥ 40 HU) on either 70-keV PPP images or conventional PVP images had significantly shorter overall survival compared with those with low delta tumors (< 40 HU) in both early stage PDAC (13.5 months vs 23.3 months; hazard ratio [HR], 1.87; 95% confidence interval [CI]: 1.01, 3.5; = .04) and advanced stage PDAC (10.8 months vs 18.0 months; HR, 2.1; 95% CI: 1.28, 3.6; = .003). Qualitative visual scoring of tumor conspicuity also showed shorter overall survival in patients with more conspicuous tumors. Highest interreader agreement for subjective delta score was 0.73 and 0.60 using iodine MD and 52-keV images, respectively.
Increased quantitative and qualitative border conspicuity (high delta) is associated with shorter survival in patients with PDAC. Agreement on the subjective qualitative characterization of PDAC borders is best achieved using iodine MD and lower-energy simulated monoenergetic images at pancreatic protocol dual-energy CT. Abdomen/GI, CT, CT-Dual Energy, CT-Quantitative, Pancreas© RSNA, 2020.
探讨基线双能 CT 图像上的差分增强在未经治疗的胰腺导管腺癌（PDAC）患者中的预后价值，重点是肿瘤-宿主界面的特征。
这是一项回顾性的、机构审查委员会批准的、符合健康保险流通与责任法案的研究，纳入了 158 例经组织病理学证实的未经治疗的 PDAC 成年患者（平均年龄 68 岁；年龄范围 40.9-88.9 岁；50%为女性），这些患者于 2011 年 12 月至 2017 年 3 月期间在胰腺双能 CT 多期扫描时接受了胰腺实质期（PPP）双能 CT 70keV、52keV 和碘物质密度（MD）图像以及门静脉期（PVP）常规 CT 图像。在胰腺实质期双能 CT 70keV、52keV 和碘 MD 图像上，在肿瘤核心、肿瘤边界、肿瘤与胰腺交界、非肿瘤胰腺和主动脉上记录感兴趣区。计算肿瘤-胰腺界面的增强梯度（delta）。结合双能 CT 值和 PVP 值，以及作为单独的预测因素，对 delta 进行评估。使用逻辑回归的受试者工作特征分析，确定基于最高 Youden 指数的每个双能 CT delta 值预测疾病结局的最佳截断点。使用 Kaplan-Meier 法生成生存曲线，并使用对数秩检验比较两组（高 delta 和低 delta）之间的差异。临床结局包括总生存期和远处转移无进展生存期。三位独立的盲法放射科医生对肿瘤的显影程度（主观 delta 评分）进行 1-5 分的评分，并使用κ 统计评估一致性。
93 例患者为晚期（50 例局部晚期和 43 例转移性），65 例为早期（48 例可切除和 17 例边界可切除）。无论是在 70keV PPP 图像上还是在常规 PVP 图像上，Delta 值较高（≥40 HU）的患者，与 Delta 值较低（＜40 HU）的患者相比，早期 PDAC（13.5 个月比 23.3 个月；危险比 [HR]，1.87；95%置信区间 [CI]：1.01，3.5； =.04）和晚期 PDAC（10.8 个月比 18.0 个月；HR，2.1；95% CI：1.28，3.6； =.003）的总生存期均明显缩短。肿瘤显影程度较高的患者，定性视觉评分也显示出较短的总生存期。碘 MD 和 52keV 图像的主观 delta 评分的最高观察者间一致性分别为 0.73 和 0.60。
在 PDAC 患者中，定量和定性边界显影程度增加（高 delta）与较短的生存期相关。使用碘 MD 和较低能量模拟单能图像在胰腺双能 CT 协议中对 PDAC 边界的主观定性特征的一致性最佳。腹部/GI、CT、CT-双能量、CT-定量、胰腺。
