比较DWI体素不相干运动模型与单指数模型对乳腺癌新辅助化疗疗效评估的应用价值研究

目的通过DWI单指数模型与体素内不相干运动(intravoxel incoherent m o t i o n,I V I M)模型相关参数的比较,探讨二者评估乳腺癌新辅助化疗(neoadjuvant chemotherapy,NAC)疗效的应用价值。材料与方法选取30例经穿刺活检病理证实为乳腺癌并接受NAC治疗的病人进行研究,根据MillerPayne病理反应分级标准将其分为有效组(19例)与无效组(11例)。回顾性分析所有病例NAC前、第二疗程末及第四疗程末MR影像学资料并获得DWI单指数模型表观弥散系数(apparent diffusion coefficient,ADC)、IVIM参数单纯弥散系数(Ds)、灌注相关弥散系数(Df)和灌注分数(f)。采用两独立样本t检验对NAC前有效组与无效组间各参数进行比较分析;通过ROC曲线对不同参数的诊断效能进行比较分析;采用配对样本t检验分别对第二、四疗程末与NAC前各参数进行比较分析。结果 NAC前有效组ADC值、Ds值显著高于无效组;ADC值、Ds值在NAC前预测疗效的敏感度、特异度等未见明显差异;NAC第二疗程末ADC值、第二、四疗程末Ds值较NAC前显著升高;第四疗程末f值较NAC前降低。结论 ADC值和Ds值有助于治疗前预测NAC疗效,且其诊断效能相当,在NAC治疗过程中,ADC、Ds及f值对判断NAC疗效有一定的作用,单指数模型是一种较好的评估乳腺癌NAC疗效的方法。

Comparison of DWI IVIM model and mono-exponential model in evaluating the response of neoadjuvant chemotherapy for breast cancer

Objective:To analyze the value of intravoxel incoherent motion (IVIM) model and DWI mono-exponential model in evaluating the response of neoadjuvant chemotherapy (NAC) for breast cancer by comparing the parameters of two models. Materials and Methods:Thirty patients confirmed breast cancer by needle biopsy who received NAC were enrolled in the study. The patients were divided into responders (n=19) and nonresponders (n=11) according to the pathological classification of Miller& Payne. ADC, Ds, Df, f and MR imaging data of patients before, after 2 and 4 cycles of NAC were analyzed retrospectively. Two independent samplest test were used to compare the parameters between the responder and nonresponders. The diagnostic efficacy of different parameters was analyzed by receiver operating characteristics (ROC) curves. The paired samplest test was used to compare the parameters after 2, 4 cycles of NAC to parameters before NAC respectively.Results:ADC and Ds before NAC were significantly higher in responders than those in the nonresponders; the sensitivity and specificity of ADC and Ds were about the same. ADC after 2 cycles of NAC was significantly higher than that before NAC Ds after 2 and 4 cycles of NAC was significantly lower than that before NAC. f after 4 cycles of NAC was significantly lower than that before NAC.Conclusions:ADC value and Ds value are helpful to predict the response to NAC before treatment, and ADC value and Ds value are equivalent in predicting the response of NAC. During the NAC course, ADC, Ds and f values play a certain role in predicting the response of NAC. Mono-exponential model is a better method to evaluate the response of NAC in breast cancer.