Jia Jemianne Bautista, Houshyar Roozbeh, Verma Sadhna, Uchio Edward, Lall Chandana
University of California, Irvine School of Medicine, 101 The City Drive South, Orange, CA 92868, United States.
Radiological Sciences University of California, Irvine School of Medicine, 101 The City Drive South, Orange, CA 92868, United States.
Eur J Radiol. 2016 Jan;85(1):261-267. doi: 10.1016/j.ejrad.2015.10.013. Epub 2015 Oct 24.
Multi-parametric prostate magnetic resonance imaging (MRI) is considered the current imaging standard for detection and staging of prostate cancer. The combination of anatomical and functional imaging provided in this exam significantly increases the accuracy of prostate cancer detection. Computed tomography (CT) imaging has so far been found to be lacking in this regard, however observations at our academic institution as well as evidence present in the literature support the proposition that CT could indeed be helpful in detecting prostate abnormalities that correspond to neoplasm. The purpose of this study was to prove that areas of focal mass-like enhancement on CT imaging directly correlate with prostate neoplasms as revealed on multi-parametric MRI and follow-up targeted biopsy.
This was a single institution retrospective study with 27 male subjects. Inclusion criteria required subjects to have a multi-parametric MRI of the prostate between January 1, 2014 and June 1, 2015 and a pelvic venous phase contrast-enhanced CT study between January 1, 2000 and June 1, 2015. Two blinded Radiologists read subjects' CT scans for any abnormalities of the prostate. CT and multi-parametric MRI results were compared and were considered concordant if focal or mass like enhancement to a greater degree than the background parenchyma was detected in the same areas of the prostate on CT scan as areas of decreased T2 signal, perfusion abnormalities, and restricted diffusion on multi-parametric MRI.
CT results were directly compared to multi-parametric MRI findings and biopsy results. The overall agreement of MRI and CT is 85.19% (95% CI: 67.52-94.08%). The positive percent agreement is 78.95% (95% CI: 54.43-93.95%) and the negative percent agreement is 100.0% (95% CL: 63.06-100.0%). When CT results are directly compared to biopsy results, sensitivity and specificity of CT are 63.64% (95% CI: 30.79-89.07%) and 100.0% (95% CI: 47.82-100.0%). The positive predictive value (PPV) is 100.0% (95% CI: 59.04-100.0%) and the negative predictive value (NPV) is 55.56% (95% CI: 21.2-86.3%). When compared to MRI, CT has a lower sensitivity and a higher specificity, as well as a higher PPV and NPV. Logistic regression analysis did not show a significant relationship between concordance of MRI and CT and Gleason score, time between studies, age, and Prostate-specific antigen (PSA) level.
Incidental focal areas of mass-like enhancement in the peripheral prostate detected on venous phase contrast-enhanced CT imaging may indeed correlate with prostate neoplasm and it would be prudent to suggest further work-up with PSA and perhaps multi-parametric MRI, especially in high-risk patients.
多参数前列腺磁共振成像（MRI）被认为是目前前列腺癌检测和分期的影像学标准。该检查提供的解剖学和功能成像相结合，显著提高了前列腺癌检测的准确性。然而，迄今为止发现计算机断层扫描（CT）成像在这方面有所欠缺，不过我们学术机构的观察结果以及文献中的证据支持这样一种观点，即CT确实有助于检测与肿瘤相对应的前列腺异常。本研究的目的是证明CT成像上的局灶性肿块样强化区域与多参数MRI及后续靶向活检所显示的前列腺肿瘤直接相关。
这是一项在单一机构进行的回顾性研究，涉及27名男性受试者。纳入标准要求受试者在2014年1月1日至2015年6月1日期间进行过前列腺多参数MRI检查，并在2000年1月1日至2015年6月1日期间进行过盆腔静脉期对比增强CT检查。两名不知情的放射科医生阅读受试者的CT扫描片，以查找前列腺的任何异常情况。将CT和多参数MRI结果进行比较，如果在CT扫描中前列腺的相同区域检测到比背景实质更大程度的局灶性或肿块样强化，且在多参数MRI上该区域表现为T2信号减低、灌注异常和扩散受限，则认为两者结果一致。
将CT结果与多参数MRI结果及活检结果直接进行比较。MRI和CT的总体一致性为85.19%（95%可信区间：67.52 - 94.08%）。阳性百分比一致性为78.95%（95%可信区间：54.43 - 93.95%），阴性百分比一致性为100.0%（95%可信区间：63.06 - 100.0%）。当将CT结果与活检结果直接比较时，CT的敏感性和特异性分别为63.64%（95%可信区间：30.79 - 89.07%）和100.0%（95%可信区间：47.82 - 100.0%）。阳性预测值（PPV）为100.0%（95%可信区间：59.04 - 100.0%），阴性预测值（NPV）为55.56%（95%可信区间：21.2 - 86.3%）。与MRI相比，CT的敏感性较低，特异性较高，PPV和NPV也较高。逻辑回归分析未显示MRI与CT的一致性与Gleason评分、两次检查之间的时间、年龄和前列腺特异性抗原（PSA）水平之间存在显著关系。
在静脉期对比增强CT成像中检测到的前列腺外周偶然出现的局灶性肿块样强化区域可能确实与前列腺肿瘤相关，对于高危患者，建议进一步进行PSA检查，或许还应进行多参数MRI检查，这是谨慎之举。
