To investigate the diagnostic value of diffusion kurtosis magnetic resonance imaging (DKI) and conventional diffusion-weighted imaging (DWI) for evaluating the response to first-line chemotherapy in unresectable pancreatic cancer. We retrospectively analyzed 21 patients with clinically and pathologically confirmed unresected pancreatic cancer who received palliative chemotherapy. Three-tesla MRI examinations containing DWI sequences with b values of 0, 100, 700, 1400, and 2100 s/mm2 were performed before and after chemotherapy. Parameters included the apparent diffusion coefficient (ADC), mean diffusion coefficient (MD), and mean diffusional kurtosis (MK). The performances of the DWI and DKI parameters in distinguishing the response to chemotherapy were evaluated by the area under the curve (AUC) of the receiver operating characteristic (ROC) curve. Overall survival (OS) was calculated from the date of first treatment to the date of death or the latest follow-up date. The ADCchange and MDchange were significantly higher in the responding group (PR group) than in the nonresponding group (non-PR group) (ADCchange: 0.21 ± 0.05 vs. 0.11 ± 0.09, P = 0.02; MDchange: 0.37 ± 0.24 vs. 0.10 ± 0.12, P = 0.002). No statistical significance was shown when comparing ADCpre, ADCpost, MKpre, MKpost, MKchange, MDpre, and MDpost between the PR and non-PR groups. The ROC curve analysis indicated that MDchange (AUC = 0.898, cutoff value = 0.7143) performed better than ADCchange (AUC = 0.806, cutoff value = 0.1369) in predicting the response to chemotherapy. The ADCchange and MDchange demonstrated strong potential for evaluating the response to chemotherapy in unresectable pancreatic cancer. The MDchange showed higher specificity in the classification of PR and non-PR than the ADCchange. Other parameters, including ADCpre, ADCpost, MKpre, MKpost, MKchange, MDpre, and MDpost, are not suitable for response evaluation. The combined model SUMchange demonstrated superior performance compared to the individual DWI and DKI models. Further experiments are needed to evaluate the potential of DWI and DKI parameters in predicting the prognosis of patients with unresectable pancreatic cancer.

中文翻译：

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弥散峰度磁共振成像和传统弥散加权成像评估不可切除胰腺癌一线化疗疗效的价值

探讨弥散峰度磁共振成像（DKI）和传统弥散加权成像（DWI）对评估不可切除胰腺癌一线化疗反应的诊断价值。我们回顾性分析了 21 例临床和病理证实的接受姑息化疗的未切除胰腺癌患者。化疗前后均进行b值为0、100、700、1400、2100 s/mm2的DWI序列的三特斯拉MRI检查。参数包括表观扩散系数 (ADC)、平均扩散系数 (MD) 和平均扩散峰度 (MK)。通过受试者工作特征（ROC）曲线的曲线下面积（AUC）评估DWI和DKI参数在区分化疗反应方面的表现。总生存期（OS）是从首次治疗日期到死亡日期或最近随访日期计算的。有反应组（PR组）的ADCchange和MDchange显着高于无反应组（非PR组）（ADCchange：0.21±0.05 vs. 0.11±0.09，P = 0.02；MDchange：0.37±0.24 vs. 0.10） ± 0.12，P = 0.002）。比较 PR 组和非 PR 组之间的 ADCpre、ADCpost、MKpre、MKpost、MKchange、MDpre 和 MDpost 时，没有显示出统计学意义。ROC曲线分析表明，MDchange（AUC = 0.898，cutoff值= 0.7143）在预测化疗反应方面优于ADCchange（AUC = 0.806，cutoff值= 0.1369）。ADCchange 和 MDchange 在评估不可切除的胰腺癌化疗反应方面表现出强大的潜力。MDchange 在 PR 和非 PR 分类方面表现出比 ADCchange 更高的特异性。其他参数，包括 ADCpre、ADCpost、MKpre、MKpost、MKchange、MDpre 和 MDpost，不适合响应评估。与单独的 DWI 和 DKI 模型相比，组合模型 SUMchange 表现出了卓越的性能。需要进一步的实验来评估 DWI 和 DKI 参数在预测不可切除胰腺癌患者预后方面的潜力。