表观扩散系数直方图对评估前列腺癌包膜外侵犯的附加价值

Added Value of Apparent Diffusion Coefficient Histogram in Predicting Extraprostatic Extension of Prostate Cancer

目的探讨磁共振表观扩散系数(ADC)直方图对评估前列腺癌包膜外侵犯(EPE)的附加价值。资料与方法回顾性连续纳入2021年1月—2022年12月于解放军总医院第一医学中心行根治性前列腺切除术,并于术前行标准多参数MRI扫描的100例前列腺癌患者,由2名放射科医师使用EPE分级系统独立评估图像,协商后确定评分。应用FireVoxel软件在ADC图上勾画全瘤体,进行直方图分析得到ADC平均值、第1、5、10、25、50、75、90、95和99百分位数ADC值(99th ADC)。比较组间差异,应用多因素Logistic回归筛选评估EPE的独立危险因素,并构建联合模型。采用受试者工作特征曲线评估效能,并比较曲线下面积。结果术后病理证实34例(34%)前列腺癌EPE阳性。ADC直方图分析显示EPE阳性与EPE阴性组间各参数差异有统计学意义(P<0.05)。多因素Logistic回归分析显示,99th ADC(OR=0.609,P=0.008)和EPE分级系统(OR=4.158,P<0.001)是评估EPE的独立危险因素。99th ADC、EPE分级系统及联合模型评估EPE的曲线下面积分别为0.756、0.805和0.856,99th ADC和EPE分级系统评估EPE的效能差异无统计学意义,联合模型的评估效能显著优于两者单独应用(Z=2.223、2.208,均P<0.05)。结论ADC直方图对术前评估EPE具有一定附加价值,99th ADC联合EPE分级系统能有效评估EPE。

Purpose To explore the additional value of apparent diffusion coefficient(ADC)histogram in predicting extraprostatic extension(EPE)of prostate cancer.Materials and Methods Consecutive patients undergoing multi-parameter MRI and subsequent radical prostatectomy from January 2021 to December 2022 were retrospectively included in this study.Two radiologists independently estimated EPE by using national cancer institute grading system for extraprostatic extension(EPE grade system),with disagreement resolved by discussion.Histogram metrics were derived from three-dimensional volumes of interest encompassing the entire lesion on ADC maps using FireVoxel,obtaining mean ADC,1st,5th,10th,25th,50th,75th,90th,95th and 99th ADC values.The ADC histograms between the groups with and without EPE were compared.Multivariable Logistic regression analysis was used to identify the independent predictive factors of EPE,and a combined model was developed.Receiver operator characteristic curve was used to evaluate the diagnostic performance,and the area under the curve was calculated and compared.Results Thirty-four patients(34%)had pathologic confirmed EPE after radical prostatectomy.ADC histogram parameters showed significant differences between patients with and without EPE(P<0.05).Multivariate Logistic regression analysis revealed 99th ADC(OR=0.609,P=0.008)and EPE grade system(OR=4.158,P<0.001)were independent predictors of EPE.For predicting EPE,the area under the curve of 99th ADC,EPE grade system and the combined model were 0.756,0.805 and 0.856,respectively.The area under the curve of 99th ADC and the EPE grade system in identifying EPE showed no significant difference.The diagnostic efficacy of combined model was significantly superior to that of 99th ADC or EPE grading system(Z=2.223,2.208,both P<0.05).Conclusion The ADC histogram parameters demonstrate additional value for preoperative prediction of EPE.Combining the 99th ADC histogram parameter with the EPE grade system may improve the diagnostic efficacy of EPE.