基于体素的肿瘤疗效影像学早期评估方法  

A Voxel-wise imaging analysis method for early evaluation of tumor treatment response

作　　者：陈琳[1,2] 夏威[1] 高欣[1] 

机构地区：[1]中国科学院苏州生物医学工程技术研究所医学影像室,苏州215163 [2]南京理工大学电子工程与光电技术学院,南京210094

出　　处：《生物医学工程学杂志》2016年第3期538-544,共7页Journal of Biomedical Engineering

基　　金：国家自然科学基金资助项目(81571772);中国科学院科研装备研制资助项目

摘　　要：针对基于肿瘤形态学或肿瘤整体平均参数的方法无法对肿瘤治疗进行早期疗效评估的问题,提出了一种基于体素的肿瘤疗效影像学早期评估方法。该方法借助动态增强磁共振成像(DCE-MRI)技术,采用弹性结合刚性配准的方法使治疗前和治疗早期的DCE-MRI肿瘤区域每个体素一一对应;根据药代动力学模型计算基于体素的容积转移常数(Ktrans),设计阈值以得到治疗早期Ktrans显著增加、显著减少与无明显变化的体素的体积分数(F+、F-与F0);利用线性回归方法获取体积分数与病理学肿瘤细胞坏死率(TCNR)的相关性,此外,根据受试者工作特征(ROC)曲线确定体积分数对治疗效果的评估能力。我们采用10例软组织肉瘤病例在治疗前与治疗早期(2周)的DCE-MRI图像数据以及治疗后的病理学肿瘤细胞坏死率进行实验,实验结果表明,F-与TCNR呈显著负相关(R2=0.832 8,P=0.000 2),F0与TCNR呈显著正相关(R2=0.788 4,P=0.000 6);而且,F-(AUC=0.905,P=0.053)与F0(AUC=0.857,P=0.087)对治疗效果具有较好的评估能力,因此我们认为F-和F0可作为一种有效的影像学生物标记物用于肿瘤疗效的早期评估。To solve the problem that the method based on tumor morphology or overall average parameters of tumor cannot conduct the early evaluation of tumor treatment response, we proposed a voxel-wise method. The voxel-wise method uses the method combining rigid and elastic registration algorithm to align the tumor area before and after treatment on the images which are acquired by the dynamic contrast enhanced magnetic resonance imaging （DCEMRI）. We calculated voxel-wise volume transport constant （K^trans）using pharmacokinetic model, and designed a threshold d to get the volume fraction of voxels which K^trans increased significantly （F＋）, K decreased significantly （F-） or had no significant change （F0）. Linear regression analysis was performed to get the correlation between volume fractions and pathological tumor cell necrosis rate （TCNR）. We then determined the ability of volume fractions to evaluate treatment response at early stage by receiver operating characteristic （ROC） curve analysis. We performed experiments on 10 patients with soft tissue sarcomas. The results indicated that F- had significant negative correlation with TCNR （R^2 = 0. 832 8, P = 0. 000 2）, F0 has significant positively correlation with TCNR （R^2 = 0. 788 4, P=0. 000 6）. In addition, F- （AUC=0. 905,P=0. 053）, F0（AUC=0. 857,P=0. 087） had a good ability in early tumor treatment response evaluation. Therefore, F- and F0 can be used as effective imaging biomarkers for early evaluation of tumor treatment.

关 键 词：肿瘤疗效早期评估 体素分析 动态增强磁共振成像 影像学生物标记物 

分 类 号：R445.2[医药卫生—影像医学与核医学] R730.44[医药卫生—诊断学]