BACKGROUND Differentiating glioma recurrence from treatment-related changes can be challenging on conventional imaging. We evaluated the efficacy of quantitative parameters measured by dual-energy spectral computed tomographic (CT) for this differentiation. METHODS Twenty-eight patients were examined by dual-energy spectral CT. The effective and normalized atomic number (Zeff and Zeff-N, respectively); spectral Hounsfield unit curve (λHU) slope; and iodine and normalized iodine concentration (IC and ICN, respectively) in the post-treatment enhanced areas were calculated. Pathological results or clinicoradiologic follow-up of ≥2 months were used for final diagnosis. Nonparametric and t-tests were used to compare quantitative parameters between glioma recurrence and treatment-related changes. Sensitivity, specificity, positive and negative predictive values (PPV and NPV, respectively), and accuracy were calculated using receiver operating characteristic (ROC) curves. Predictive probabilities were used to generate ROC curves to determine the diagnostic value. RESULTS Examination of pre-contrast λHU, Zeff, Zeff-N, IC, ICN, and venous phase ICN showed no significant differences in quantitative parameters (P > 0.05). Venous phase λHU, Zeff, Zeff-N, and IC in glioma recurrence were higher than in treatment-related changes (P < 0.001). The optimal venous phase threshold was 1.03, 7.75, 1.04, and 2.85 mg/cm3, achieving 66.7, 91.7, 83.3, and 91.7% sensitivity; 100.0, 77.8, 88.9, and 77.8% specificity; 100.0, 73.3, 83.3, and 73.3% PPV; 81.8, 93.3, 88.9, and 93.3% NPV; and 86.7, 83.3, 86.7, and 83.3% accuracy, respectively. The respective areas under the curve (AUCs) were 0.912, 0.912, 0.931, and 0.910 in glioma recurrence and treatment-related changes. CONCLUSIONS Glioma recurrence could be potentially differentiated from treatment-related changes based on quantitative values measured by dual-energy spectral CT imaging.

中文翻译：

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从治疗相关变化中区分脑胶质瘤复发的双能谱CT定量参数：初步研究。

背景技术区分神经胶质瘤复发与与治疗相关的改变对常规成像可能是具有挑战性的。我们评估了通过双能谱计算机断层扫描（CT）测量的定量参数对这种区分的功效。方法对28例患者进行双能谱CT检查。有效原子数和归一化原子数（分别为Zeff和Zeff-N）；谱Hounsfield单位曲线（λHU）斜率; 计算了治疗后增强区的碘和标准化碘浓度（分别为IC和ICN）。≥2个月的病理结果或临床放射学随访用于最终诊断。非参数和t检验用于比较神经胶质瘤复发与治疗相关变化之间的定量参数。敏感性，特异性，正和负预测值（分别为PPV和NPV）和准确性是使用接收器工作特征（ROC）曲线计算的。使用预测概率来生成ROC曲线以确定诊断值。结果对比前的λHU，Zeff，Zeff-N，IC，ICN和静脉相ICN的检查在定量参数上没有显着差异（P> 0.05）。胶质瘤复发的静脉期λHU，Zeff，Zeff-N和IC高于治疗相关变化（P <0.001）。最佳静脉相位阈值为1.03、7.75、1.04和2.85 mg / cm3，达到66.7、91.7、83.3和91.7％的灵敏度；100.0、77.8、88.9和77.8％的特异性；PPV为100.0、73.3、83.3和73.3％；NPV分别为81.8、93.3、88.9和93.3％；精度分别为86.7％，83.3％，86.7和83.3％。胶质瘤复发和治疗相关变化的曲线下面积（AUC）分别为0.912、0.912、0.931和0.910。结论根据双能谱CT成像测量的定量值，可以将胶质瘤复发与治疗相关变化区分开。