Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, Room C-278, New York, NY 10065, USA.
Radiology. 2012 Nov;265(2):478-87. doi: 10.1148/radiol.12120041. Epub 2012 Sep 5.
To prospectively evaluate diagnostic performance of T2-weighted magnetic resonance (MR) imaging and MR spectroscopic imaging in detecting lesions stratified by pathologic volume and Gleason score in men with clinically determined low-risk prostate cancer.
The institutional review board approved this prospective, HIPAA-compliant study. Written informed consent was obtained from 183 men with clinically low-risk prostate cancer (cT1-cT2a, Gleason score≤6 at biopsy, prostate-specific antigen [PSA] level<10 ng/mL [10 μg/L]) undergoing MR imaging before prostatectomy. By using a scale of 1-5 (score 1, definitely no tumor; score 5, definitely tumor), two radiologists independently scored likelihood of tumor per sextant on T2-weighted images. Two spectroscopists jointly recorded locations of lesions with metabolic features consistent with tumor on MR spectroscopic images. Whole-mount step-section histopathologic analysis constituted the reference standard. Diagnostic performance at sextant level (T2-weighted imaging) and detection sensitivities (T2-weighted imaging and MR spectroscopic imaging) for lesions of 0.5 cm3 or larger were calculated.
For T2-weighted imaging, areas under the receiver operating characteristic curves for sextant-level detection were 0.77 (reader 1) and 0.82 (reader 2). For lesions of ≥0.5 cm3 and, 1<cm3, sensitivities were significantly lower when the lesion Gleason score was ≤6 (0.44 [reader 1] and 0.61 [reader 2]) rather than when the Gleason score was ≥7 (0.73, P=.02 [reader 1]; and 0.84, P=.05 [reader 2]). For lesions of ≥1 cm3, lesion Gleason score did not significantly affect sensitivity (0.83 [reader 1] and 1.00 [reader 2] for Gleason score≤6 vs 0.82 and 0.92 for Gleason score≥7; P≥.07). MR spectroscopic imaging sensitivity was low and was not significantly affected by pathologic lesion volume or Gleason score.
In men with clinically low-risk prostate cancer, detection of lesions of <1 cm3 with T2-weighted imaging is significantly dependent on lesion Gleason score; detection of lesions of ≥1 cm3 is significantly better than detection of smaller lesions and is not affected by lesion Gleason score. The role of MR spectroscopic imaging alone in this population is limited.
前瞻性评估 T2 加权磁共振（MR）成像和 MR 波谱成像在检测经病理体积和 Gleason 评分分层的病变中的诊断性能，这些病变患者为临床诊断为低危前列腺癌的男性。
本研究经机构审查委员会批准，符合 HIPAA 规定。183 名经临床诊断为低危前列腺癌（cT1-cT2a，活检时 Gleason 评分≤6，前列腺特异性抗原[PSA]水平<10ng/mL[10μg/L]）的男性患者在前列腺切除术前行 MR 成像，他们均签署了书面知情同意书。两位放射科医生采用 1-5 分制（1 分，肯定无肿瘤；5 分，肯定有肿瘤）独立对 T2 加权图像上每一个六区分叶的肿瘤可能性进行评分。两位波谱仪专家共同记录 MR 波谱图像上代谢特征符合肿瘤的病变位置。全距分段组织病理学分析作为参考标准。计算六分区水平（T2 加权成像）和病变检测敏感性（T2 加权成像和 MR 波谱成像）的诊断性能，病变体积≥0.5cm3。
对于 T2 加权成像，读者 1 和读者 2 的六分区检测的受试者工作特征曲线下面积分别为 0.77 和 0.82。对于≥0.5cm3 和 1cm3 大小的病变，当病变 Gleason 评分为≤6 时，检测敏感性显著降低（读者 1：0.44；读者 2：0.61），而当 Gleason 评分≥7 时，检测敏感性显著增高（读者 1：0.73，P=.02；读者 2：0.84，P=.05）。对于≥1cm3 的病变，病变 Gleason 评分并不显著影响敏感性（读者 1：0.83 和 1.00，Gleason 评分≤6；读者 2：0.82 和 0.92，Gleason 评分≥7；P≥.07）。MR 波谱成像的敏感性较低，且不受病理病变体积或 Gleason 评分的影响。
在临床诊断为低危前列腺癌的男性中，T2 加权成像检测<1cm3 的病变显著依赖于病变 Gleason 评分；检测≥1cm3 的病变明显优于检测较小的病变，且不依赖于病变 Gleason 评分。在该人群中，MR 波谱成像的作用有限。
