高场强MR对老年人前列腺癌分期预测的临床价值

The clinical role of high-field magnetic resonance in the staging of prostate cancer for elderly patients

目的探讨高场强MR预测前列腺癌病理分期的临床价值。方法48例手术病理证实的局限性前列腺癌患者，术前分别进行高场强MR检查，应用美国GE公司1．5T（GEExcite HD Twinspeed 1．5T）超导磁共振成像系统，扫描序列包括轴位快速自旋回波T1加权像、快速自旋回波T2加权像、T2脂肪抑制轴位和冠状位像及轴位弥散加权像。应用Whitmore-Jewett方法对前列腺癌进行分期。结果48例局限性前列腺癌患者，32例术前MR诊断B期，16例为C1期。术前MR诊断为B期者，43．8％（14／32）术后病理分期为C1期，其中1例为C2期；术前MR诊断C期者。术后病理12．5％（2／16）为B2期。MR对前列腺癌的分期与术后病理结果有显著相关性（r=0．451。P〈0．001），能够较准确地预测病理结果（X^2=10．628，P＜0.01）。MR分期对局限于前列腺内肿瘤的预测为56．3％（18／32），对浸润包膜及包膜外肿瘤的预测为87．5％（14／16）；MR对局限性前列腺癌分期的敏感性为90．0％。特异性50．0％。准确性66．7％。结论 高场强MR对局限性前列腺癌能够预测前列腺癌的病理分期，能够更准确地预测肿瘤对包膜及包膜外的浸润情况。

Objective To evaluate the clinical significance of high-field magnetic resonance （MR） in diagnosis of prostate cancer staging for elderly patients before radical prostatectomy. Methods Forty-eight patients with prostate cancer that confirmed by pathologic results after radical prostatectomy were reviewed to assess the accuracy of high-field MR staging in accordance with the pathological staging. MR imaging（MRI） was performed with 1.5T MRI systems （GE Excite HD Twinspeed 1.5T）, the pulse sequences included axial FSE fat saturation and without fat saturation T2-weighted imaging, axial FSE Tl-weighted imaging, coronal T2-weighted imaging, and axial diffusion-weighted imaging. The modus of Whitmore-Jewett was used for staging. Results Thirtytwo of 48 prostate cancer patients were classified into stage B by MRI, of them 14 （14/32, 43.8%） were C1 and 1 （1/32, 3.1%） was C2 staged by pathologically after prostatectomy. Of the 16 patients were stage C with MRI, 2 （2/16, 12.5%） of them were pathological B2. The staging of MRI had significant correlation with pathological staging results （X^2 = 10. 628, P 〈 0.01）, and the positive predictive value（PPV） of MRI for the localized cancer within prostate gland was 56.3% （18/32）, and the negative predictive value（NPV） was 87.5% （14/16）. The sensitivity, specificity and accuracy of MR staging for the localized cancer within prostate gland were 90.0%, 50.0% and 66.7% respectively. Conclusions High-field MRI may predict pathological staging results for localized cancer within prostate gland, and the high-field MRI is of more accuracy in predicting the infiltrating of prostate capsule.