Vos Eline K, Kobus Thiele, Litjens Geert J S, Hambrock Thomas, Hulsbergen-van de Kaa Christina A, Barentsz Jelle O, Maas Marnix C, Scheenen Tom W J
From the Departments of *Radiology and Nuclear Medicine, and †Pathology, Radboud University Medical Center, Nijmegen, the Netherlands.
Invest Radiol. 2015 Aug;50(8):490-7. doi: 10.1097/RLI.0000000000000157.
The aim of this study was to determine and validate the optimal combination of parameters derived from 3-T diffusion-weighted imaging, dynamic contrast-enhanced imaging, and magnetic resonance (MR) spectroscopic imaging for discriminating low-grade from high-grade prostate cancer (PCa).
The study was approved by the institutional review board, and the need for informed consent was waived. Ninety-four patients with PCa who had undergone multiparametric MR imaging (MRI) before prostatectomy were included. Cancer was indicated on T2-weighted images, blinded to any functional data, with prostatectomy specimens as the reference standard. Tumors were classified as low grade or high grade based on Gleason score; peripheral zone (PZ) and transition zone (TZ) tumors were analyzed separately. In a development set (43 patients), the optimal combination of multiparametric MRI parameters was determined using logistic regression modeling. Subsequently, this combination was evaluated in a separate validation set (51 patients).
In the PZ, the 25th percentile of apparent diffusion coefficient (ADC) derived from diffusion-weighted imaging and washout (WO25) derived from dynamic contrast-enhanced MRI offered the optimal combination of parameters. In the TZ, WO25 and the choline over spermine + creatine ratio (C/SC) derived from MR spectroscopic imaging showed the highest discriminating performance. Using the models built with the development set, 48 (74%) of 65 cancer lesions were classified correctly in the validation set.
Multiparametric MRI is a useful tool for the discrimination between low-grade and high-grade PCa and performs better than any individual functional parameter in both the PZ and TZ. The 25th percentile of ADC + WO25 offered the optimal combination in the PZ, and the choline over spermine + creatine ratio + WO25 offered the optimal combination in the TZ. The ADC parameter has no additional value for the assessment of PCa aggressiveness in the TZ.
本研究旨在确定并验证从3T扩散加权成像、动态对比增强成像和磁共振（MR）波谱成像得出的参数的最佳组合，以鉴别低级别与高级别前列腺癌（PCa）。
本研究经机构审查委员会批准，无需知情同意。纳入94例前列腺切除术前接受多参数磁共振成像（MRI）的PCa患者。T2加权图像显示有癌症，对任何功能数据均不知情，以前列腺切除标本作为参考标准。根据Gleason评分将肿瘤分为低级别或高级别；分别分析外周带（PZ）和移行带（TZ）肿瘤。在一个开发集（43例患者）中，使用逻辑回归模型确定多参数MRI参数的最佳组合。随后，在一个单独的验证集（51例患者）中对该组合进行评估。
在PZ中，扩散加权成像得出的表观扩散系数（ADC）的第25百分位数和动态对比增强MRI得出的廓清率（WO25）提供了最佳参数组合。在TZ中，WO25和MR波谱成像得出的胆碱与精胺+肌酸的比值（C/SC）显示出最高的鉴别性能。使用在开发集中构建的模型，验证集中65个癌症病灶中的48个（74%）被正确分类。
多参数MRI是鉴别低级别和高级别PCa的有用工具，在PZ和TZ中均比任何单个功能参数表现更好。ADC的第25百分位数+WO25在PZ中提供了最佳组合，胆碱与精胺+肌酸的比值+WO25在TZ中提供了最佳组合。ADC参数对评估TZ中PCa的侵袭性没有额外价值。
