Mürtz Petra, Penner Arndt-Hendrik, Pfeiffer Anne-Kristina, Sprinkart Alois M, Pieper Claus C, König Roy, Block Wolfgang, Schild Hans H, Willinek Winfried A, Kukuk Guido M
Department of Radiology, University of Bonn, Bonn, Germany.
Onco Targets Ther. 2016 Oct 19;9:6425-6433. doi: 10.2147/OTT.S113909. eCollection 2016.
The aim of this study was to evaluate an intravoxel incoherent motion (IVIM) model-based analysis of diffusion-weighted imaging (DWI) for assessing the response of hepatocellular carcinoma (HCC) to locoregional therapy.
Respiratory-gated DWI (=0, 50, and 800 s/mm) was retrospectively analyzed in 25 patients who underwent magnetic resonance imaging at 1.5 T before and 6 weeks following the first cycle of transarterial chemoembolization therapy, transarterial ethanol-lipiodol embolization therapy, and transarterial radioembolization therapy. In addition to the determination of apparent diffusion coefficient, ADC(0,800), an estimation of the diffusion coefficient, ', and the perfusion fraction, ', was performed by using a simplified IVIM approach. Parameters were analyzed voxel-wise. Tumor response was assessed in a central slice by using a region of interest (ROI) covering the whole tumor. HCCs were categorized into two groups, responders and nonresponders, according to tumor size changes on first and second follow ups (if available) and changes of contrast-enhanced region on the first follow up.
In total, 31 HCCs were analyzed: 17 lesions were assigned to responders and 14 were to nonresponders. In responders, ADC(0,800) and ' were increased after therapy by ~30% (=0.00004) and ~42% (=0.00001), respectively, whereas ' was decreased by ~37% (=0.00094). No significant changes were found in nonresponders. Responders and nonresponders were better differentiated by changes in ' than by changes in ADC(0,800) (area under the curve =0.878 vs 0.819 or 0.714, respectively).
In patients with HCCs undergoing embolization therapy, diffusion changes were better reflected by ' than by conventional ADC(0,800), which is influenced by counteracting perfusion changes as assessed by '.
本研究旨在评估基于体素内不相干运动（IVIM）模型的扩散加权成像（DWI）分析在评估肝细胞癌（HCC）对局部区域治疗反应中的应用。
对25例在接受经动脉化疗栓塞治疗、经动脉乙醇-碘油栓塞治疗和经动脉放射性栓塞治疗的第一个周期之前及之后6周进行1.5T磁共振成像的患者进行了回顾性呼吸门控DWI（=0、50和800 s/mm²）分析。除了测定表观扩散系数ADC(0,800)外，还采用简化的IVIM方法对扩散系数D*和灌注分数f进行了估计。参数按体素进行分析。通过使用覆盖整个肿瘤的感兴趣区域（ROI）在中心层面评估肿瘤反应。根据首次和第二次随访（如有）时的肿瘤大小变化以及首次随访时对比增强区域的变化，将HCC分为两组，反应者和无反应者。
共分析了31个HCC：17个病灶被归为反应者，14个为无反应者。在反应者中，治疗后ADC(0,800)和D分别增加了约30%（P=0.00004）和约42%（P=0.00001），而f降低了约37%（P=0.00094）。在无反应者中未发现显著变化。与ADC(0,800)的变化相比，反应者和无反应者通过D的变化能更好地鉴别（曲线下面积分别为0.878对0.819或0.714）。
在接受栓塞治疗的HCC患者中，扩散变化通过D比通过受D评估的灌注变化抵消影响的传统ADC(0,800)能更好地反映。
