扩散加权成像表观扩散系数预测鼻咽癌同步放化疗疗效

目的 探讨DWI中ADC值预测鼻咽癌同步放化疗疗效的价值。方法 收集经病理证实并于我院接受同步放化疗的鼻咽癌患者65例，于治疗前行MRI及DWI，测量肿瘤平均、最高及最低ADC值，于治疗中（放疗剂量达50 Gy）、治疗末再次行MRI，计算肿瘤消退率。分析治疗前肿瘤ADC值与肿瘤消退率的相关性；比较治疗末完全缓解（CR）患者及非CR患者治疗前ADC值差异；绘制ROC曲线，评估治疗前ADC值预测疗效的效能。结果 治疗前肿瘤平均ADC值、最高ADC值与治疗中消退率呈负相关（r=-0.463、-0.552，P均<0.001）、与治疗末消退率呈负相关（r=-0.504、-0.481，P均<0.001）；CR患者及非CR患者治疗前平均ADC值分别为（0.98±0.12）×10^-3 mm²/s及（1.14±0.13）×10^-3 mm²/s，最高ADC值分别为（1.16±0.21）×10^-3 mm²/s及（1.42±0.23）×10^-3 mm²/s，CR与非CR患者治疗前平均及最高ADC值差异均有统计学意义（P均<0.001）。以肿瘤治疗前平均ADC值1.09×10^-3 mm²/s为界值，其预测同步放化疗后CR的敏感度、特异度及准确率分别为82.5%、76.0%及80.0%，曲线下面积为0.816。结论 治疗前肿瘤平均及最高ADC值可预测鼻咽癌放化疗疗效，有望为个体化治疗鼻咽癌提供依据。

Diffusion-weighted imaging for predicting therapeutic effect of chemoradiotherapy in nasopharyngeal carcinoma

Objective To explore the value of ADC in DWI for predicting therapeutic effect of chemoradiotherapy in nasopharyngeal carcinoma. Methods Totally 65 patients with nasopharyngeal carcinoma confirmed by pathology received chemoradiotherapy. All the patients underwent MRI and DWI to obtain the mean, maximum and minimum ADC value of the tumor before therapy. MRI was performed again during treatment (radiotherapy dose of 50 Gy) and after treatment to calculate the tumor regression rate. The correlation between pretherapeutic ADC value and tumor regression rate was analyzed. The pretherapeutic ADC value was compared between patients of complete response (CR) and non-CR. ROC was drawn to assess the ability of pretherapeutic ADC in predicting therapeutic effect. Results The mean and maximum ADC before therapy showed negative correlation with tumor regression rate during treatment (r=-0.463 and -0.552, both P<0.001) and after treatment (r=-0.504 and -0.481, both P<0.001). There was statistical difference between patients of CR and non-CR for pretherapeutic mean ADC (×10^-3 mm²/s vs×10^-3 mm²/s, P<0.001) and maximum ADC (×10^-3 mm²/s vs×10^-3 mm²/s, P<0.001). ROC curve showed that the sensitivity, specificity, and accuracy of pretherapeutic mean ADC value in predicting CR was 82.5%, 76.0% and 80.0% respectively, with the cut-off value of 1.09×10^-3 mm²/s, and the area under curve was 0.816. Conclusion Pretherapeutic mean and maximum ADC value of tumor can predict therapeutic effect of chemoradiotherapy in nasopharyngeal carcinoma, potential to be helpful to individualized therapy.