Citak-Er Fusun, Vural Metin, Acar Omer, Esen Tarik, Onay Aslihan, Ozturk-Isik Esin
Department of Genetics and Bioengineering, Yeditepe University, İnönü Mah., Kayışdağı Cad, 26 Ağustos Yerleşimi, Ataşehir, 34755 Istanbul, Turkey.
Department of Radiology, VKF American Hospital, 34365 Istanbul, Turkey.
Biomed Res Int. 2014;2014:690787. doi: 10.1155/2014/690787. Epub 2014 Dec 2.
This study aimed at evaluating linear discriminant analysis (LDA) and support vector machine (SVM) classifiers for estimating final Gleason score preoperatively using multiparametric magnetic resonance imaging (mp-MRI) and clinical parameters.
Thirty-three patients who underwent mp-MRI on a 3T clinical MR scanner and radical prostatectomy were enrolled in this study. The input features for classifiers were age, the presence of a palpable prostate abnormality, prostate specific antigen (PSA) level, index lesion size, and Likert scales of T2 weighted MRI (T2w-MRI), diffusion weighted MRI (DW-MRI), and dynamic contrast enhanced MRI (DCE-MRI) estimated by an experienced radiologist. SVM based recursive feature elimination (SVM-RFE) was used for eliminating features. Principal component analysis (PCA) was applied for data uncorrelation.
Using a standard PCA before final Gleason score classification resulted in mean sensitivities of 51.19% and 64.37% and mean specificities of 72.71% and 39.90% for LDA and SVM, respectively. Using a Gaussian kernel PCA resulted in mean sensitivities of 86.51% and 87.88% and mean specificities of 63.99% and 56.83% for LDA and SVM, respectively.
SVM classifier resulted in a slightly higher sensitivity but a lower specificity than LDA method for final Gleason score prediction for prostate cancer for this limited patient population.
本研究旨在评估线性判别分析(LDA)和支持向量机(SVM)分类器,以利用多参数磁共振成像(mp-MRI)和临床参数术前估计最终的Gleason评分。
本研究纳入了33例在3T临床MR扫描仪上接受mp-MRI检查并接受根治性前列腺切除术的患者。分类器的输入特征包括年龄、可触及的前列腺异常情况、前列腺特异性抗原(PSA)水平、索引病灶大小,以及由经验丰富的放射科医生估计的T2加权MRI(T2w-MRI)、扩散加权MRI(DW-MRI)和动态对比增强MRI(DCE-MRI)的李克特量表。基于支持向量机的递归特征消除(SVM-RFE)用于特征消除。主成分分析(PCA)用于数据去相关。
在最终Gleason评分分类前使用标准PCA,LDA和SVM的平均敏感性分别为51.19%和64.37%,平均特异性分别为72.71%和39.90%。使用高斯核PCA,LDA和SVM的平均敏感性分别为86.51%和87.88%,平均特异性分别为63.99%和56.83%。
对于这一有限的患者群体,在预测前列腺癌最终Gleason评分方面,SVM分类器的敏感性略高于LDA方法,但特异性较低。