From the Departments of Radiology (N.T., X.W., F.X., G.W.).
Radiation and Medical Oncology (Y.Z., L.C.), Zhongnan Hospital of Wuhan University, Wuhan University, Hubei, China.
AJNR Am J Neuroradiol. 2019 Feb;40(2):326-333. doi: 10.3174/ajnr.A5925. Epub 2019 Jan 10.
The prediction of treatment response is important in planning and modifying the chemoradiation therapy regimen. This study aimed to explore the quantitative histogram indices for treatment-response prediction of nasopharyngeal carcinoma based on diffusional kurtosis imaging compared with a standard ADC value (ADC).
Thirty-six patients with an initial diagnosis of locoregionally advanced nasopharyngeal carcinoma and diffusional kurtosis imaging acquisitions before and after neoadjuvant chemotherapy were enrolled. Patients were divided into respond-versus-nonrespond groups after neoadjuvant chemotherapy and residual-versus-nonresidual groups after radiation therapy. Histogram parameters of diffusional kurtosis imaging-derived parameters (ADC, ADC coefficient corrected by the non-Gaussain model [D], apparent kurtosis coefficient without a unit [K]) were calculated. The ADC was calculated on the basis of intravoxel incoherent movement data. The intraclass correlation coefficient, Kolmogorov-Smirnov test, Student test or Mann-Whitney test, and receiver operating characteristic analysis were performed.
Most of the parameters had good-to-excellent consistency (intraclass correlation coefficient = 0.675-0.998). The pre-ADC, pre-ADC (10th, 25th, 50th percentiles), pre-D (10th, 25th, 50th percentiles), and pre-K were significantly different between the respond and nonrespond groups, while the pre-ADC, pre-K, post-ADC, post-K, post-K, and the percentage change of parameters before and after neoadjuvant chemotherapy (▵ADC%) were significantly different between the residual and nonresidual groups (all < .05). Receiver operating characteristic analysis indicated that setting pre-D = 0.875 × 10mm/s as the cutoff value could result in optimal diagnostic performance for neoadjuvant chemotherapy response prediction (area under the curve = 0.814, sensitivity = 0.70, specificity = 0.92), while the post-K = 1.035 (area under the curve = 0.829, sensitivity = 0.78, specificity = 0.72), and▵ADC% = 0.253 (area under the curve = 0.833, sensitivity = 0.94, specificity = 0.72) were optimal for radiation therapy response prediction.
Histogram analysis of diffusional kurtosis imaging may potentially predict the neoadjuvant chemotherapy and short-term radiation therapy response in locoregionally advanced nasopharyngeal carcinoma, therefore providing evidence for modification of the treatment regimen.
预测治疗反应对于规划和修改放化疗方案非常重要。本研究旨在探讨扩散峰度成像的定量直方图指标在预测局部晚期鼻咽癌治疗反应方面的作用，并与标准 ADC 值（ADC）进行比较。
本研究纳入了 36 例初诊为局部晚期鼻咽癌并接受新辅助化疗前后扩散峰度成像采集的患者。新辅助化疗后，根据患者的治疗反应将其分为有效组和无效组；放疗后，根据肿瘤残留情况将患者分为残留组和非残留组。计算扩散峰度成像衍生参数的直方图参数（ADC、校正非高斯模型的 ADC 系数[D]、无单位的表观峰度系数[K]）。ADC 是基于体素内不相干运动数据计算的。采用组内相关系数、柯尔莫哥洛夫-斯米尔诺夫检验、Student t 检验或曼-惠特尼 U 检验和受试者工作特征分析进行分析。
大多数参数的一致性较好（组内相关系数=0.675-0.998）。有效组和无效组间的治疗前 ADC、治疗前 ADC（10 百分位、25 百分位、50 百分位）、治疗前 D（10 百分位、25 百分位、50 百分位）和治疗前 K 有显著差异，而治疗后 ADC、治疗后 K、治疗前后 ADC 的变化百分比（△ADC%）在残留组和非残留组间有显著差异（均<0.05）。受试者工作特征分析表明，以治疗前 D=0.875×10mm/s 作为截断值，对新辅助化疗反应的预测具有最佳诊断性能（曲线下面积=0.814，灵敏度=0.70，特异度=0.92），而治疗后 K=1.035（曲线下面积=0.829，灵敏度=0.78，特异度=0.72）和△ADC%=0.253（曲线下面积=0.833，灵敏度=0.94，特异度=0.72）对预测放疗反应最佳。
扩散峰度成像的直方图分析可能有助于预测局部晚期鼻咽癌的新辅助化疗和短期放疗反应，为治疗方案的调整提供依据。
