体素内不相干运动MRI预测鼻咽癌放疗化疗敏感性的初步研究

To investigate the sensitivity of chemoradiotherapy on nasopharyngeal carcinoma using intravoxel incoherent motion MRI

目的探讨体素内不相干运动磁共振(IVIM-MRI)在预测鼻咽癌(NPC)放、化疗敏感性的应用价值。方法本研究为回顾性临床和影像资料分析。搜集我院2011年12月1日至2018年12月30日初治的,经病理确诊的TNM分期3期(30例)或4期(38例)的鼻咽癌患者共68例。所有患者接受标准方案同期放化疗后,根据实体瘤疗效评价标准(RECIST)分为敏感组(45例)、不敏感组(23例)。放、化疗前后所有患者行3.0T常规MRI及13个b值(区间0~800s/mm^2)IVIM检查。由2名有经验的影像诊断医师分别独立分析图像并选取病灶区ROIs通过后处理软件计算IVIM各参数值,包括真实扩散系数(D值)、灌注相关扩散系数(D*值)、灌注分数(f值)和ADC值。采用组内相关系数(ICC)评估2名医师测量数值的一致性,敏感组与不敏感组间IVIM参数值的比较采用Mann-WhitneyU检验。结果2名医师测量数值的一致性好,D值、f值、D*值、ADC值的ICC分别为0.937、0.922、0.902、0.893。敏感组D值、D*值分别为(0.69±0.06)、(161.33±11.50)×10^-3mm^2/s,不敏感组分别为(0.52±0.10)、(126.96±10.27)×10^-3mm^2/s,差异均有统计学意义(U值分别为51.5、18.0,P值均<0.01);敏感组f值(16.68±1.94)%、ADC值(1.23±0.11)×10^-3mm^2/s,不敏感组分别为(16.40±1.11)%、(1.25±0.10)×10^-3mm^2/s,两组差异均无统计学意义(U值分别为434.5、427.0,P值均>0.05)。结论IVIM对鼻咽癌放、化疗敏感性的预测临床实用性较高。D值及D*值高提示鼻咽癌患者对放化疗敏感,且D*值高表明鼻咽癌病灶内肿瘤新生血管丰富及肿瘤实质部分血流灌注增加。

Objective To investigate the application value of intravoxel incoherent motion (IVIM) MRI for evaluating the sensitivity of chemoradiotherapy on nasopharyngeal carcinoma (NPC). MethodsSixty eight consecutive patients newly diagnosed with NPC in the stage of T3 (30 patients) or T4 (38 patients) were retrospectively enrolled. They were divided into effective group (45 patients) and poor-effective group (23 patients) clinically after a standard chemoradiotherapy according to the RECIST criteria. IVIM with 13 b-values (range,0 to 800 s/mm^2) and general MRI were performed at 3.0 T MR scanner before and after chemoradiotherapy. Two radiologists major in MRI diagnose analyzed all images independently and placed regions of interest (ROIs). Intraclass correlation coefficient (ICC) was used to evaluate intra-observer and inter-observer agreement. And Mann-Whitney test was used to assess the differences between the two groups. ResultsThe reproducibility between intra-observer and inter-observer was relatively good. Statistically,D [(0.69±0.06)×10^-3 mm^2/s vs.(0.52±0.10)×10^-3 mm^2/s;U=51.5, P<0.01)]and D*[(161.33±11.50)×10^-3 mm^2/s vs.(126.96±10.27)×10^-3 mm^2/s;U=18.0, P<0.01] were significantly higher in effective group than those in poor-effective group,whereas the difference of f (16.68±1.94% vs. 16.40±1.11%, U=434.5, P=0.282) and ADC (1.23±0.11)×10-3 mm2/s vs.(1.25±0.10)×10-3 mm2/s, U=427.0, P=0.240) could not reach statistical significance between the 2 groups (P>0.05). ConclusionsIVIM may be potentially useful in assessing the chemoradiotherapy on NPC. The higher D value combined with higher D* value might indicate the chemoradiotherapy on NPC is more sensitive,and the higher D* value might reflect increased blood vessel generation and parenchymal perfusion in NPC.