Impact of the integration of proton magnetic resonance imaging spectroscopy to PI-RADS 2 for prediction of high grade and high stage prostate cancer

Abstract Objective: To compare the predictions of dominant Gleason pattern ≥ 4 or non-organ confined disease with Prostate Imaging Reporting and Data System (PI-RADS v2) with or without proton magnetic resonance spectroscopic imaging (1H-MRSI). Materials and Methods: Thirty-nine men underwent 3-tesla endorectal multiparametric MRI including 1H-MRSI and prostatectomy. Two radiologists assigned PI-RADS v2 and 1H-MRSI scores to index lesions. Statistical analyses used logistic regressions, receiver operating characteristic (ROC) curves, and 2x2 tables for diagnostic accuracies. Results: The sensitivity and specificity of 1H-MRSI and PI-RADS v2 for high-grade prostate cancer (PCa) were 85.7% (57.1%) and 92.9% (100%), and 56% (68.0%) and 24.0% (24.0%). The sensitivity and specificity of 1H-MRSI and PI-RADS v2 for extra-prostatic extension (EPE) were 64.0% (40%) and 20.0% (48%), and 50.0% (57.1%) and 71.4% (64.3%). The area under the ROC curves (AUC) for prediction of high-grade prostate cancer were 0.65 and 0.61 for PI-RADS v2 and 0.72 and 0.70 when combined with 1H-MRSI (readers 1 and 2, p = 0.04 and 0.21). For prediction of EPE the AUC were 0.54 and 0.60 for PI-RADS v2 and 0.55 and 0.61 when combined with 1H-MRSI (p > 0.05). Conclusion: 1H-MRSI might improve the discrimination of high-grade prostate cancer when combined to PI-RADS v2, particularly for PI-RADS v2 score 4 lesions, but it does not affect the prediction of EPE.

摘要
研究目的：对比单独使用或联合氢质子磁共振波谱成像（1H-MRSI）的前列腺影像报告和数据系统（Prostate Imaging Reporting and Data System，PI-RADS v2），对主要格里森分型≥4的病灶及非器官局限性病变的预测效能。

材料与方法：纳入39名男性受试者，均接受包含1H-MRSI的3特斯拉直肠内多参数磁共振成像检查，并接受根治性前列腺切除术。两名放射科医师对靶病灶分别进行PI-RADS v2评分及1H-MRSI评分。统计分析采用逻辑回归分析、受试者工作特征（Receiver Operating Characteristic，ROC）曲线及四格表法评估诊断效能。

结果：针对高级别前列腺癌（Prostate Cancer，PCa），1H-MRSI单独检测的敏感度与特异度分别为85.7%（读者2为57.1%）、92.9%（读者2为100%）；PI-RADS v2单独检测的敏感度与特异度分别为56.0%（读者2为68.0%）、24.0%（读者2为24.0%）。针对前列腺外侵犯（Extra-prostatic Extension，EPE），1H-MRSI单独检测的敏感度与特异度分别为64.0%（读者2为40.0%）、20.0%（读者2为48.0%）；PI-RADS v2单独检测的敏感度与特异度分别为50.0%（读者2为57.1%）、71.4%（读者2为64.3%）。在高级别前列腺癌的预测中，单独使用PI-RADS v2的受试者工作特征曲线下面积（Area Under the Receiver Operating Characteristic Curve，AUC）分别为0.65（读者1）与0.61（读者2）；联合1H-MRSI后则分别为0.72（读者1）与0.70（读者2），两组差异具有统计学意义（读者1：P=0.04；读者2：P=0.21）。针对EPE的预测，单独使用PI-RADS v2的AUC分别为0.54（读者1）与0.60（读者2），联合1H-MRSI后分别为0.55（读者1）与0.61（读者2），两组差异均无统计学意义（均P>0.05）。

结论：氢质子磁共振波谱成像联合PI-RADS v2可提升对高级别前列腺癌的鉴别效能，尤其针对PI-RADS v2评分为4分的病灶，但对前列腺外侵犯的预测无显著改善作用。