18F-PSMA PET/CT联合多参数磁共振对前列腺癌分级的诊断价值

Diagnostic value of 18F-prostate specific membrane antigen PET/CT combined with multiparametric-MRI in identifying the grade group of prostate cancer

目的探讨联合应用18F-前列腺特异性膜抗原(PSMA)PET/CT和多参数磁共振(mpMRI)检查对不同级别前列腺癌的诊断预测能力。方法回顾性分析2018年9月至2021年5月北京医院收治的49例经穿刺活检确诊为前列腺癌患者的病例资料,中位年龄68(64~75)岁。中位PSA水平14.74(7.75~24.19)ng/ml。穿刺前均行mpMRI检查。穿刺病理的国际泌尿病理协会(ISUP)分级分组1组6例(12.2%),2组16例(32.7%),3组12例(24.5%),≥4组15例(10.9%)。将患者分为ISUP分级分组高级别组(≥4组)和低级别组(1~3组),两组的中位年龄分别为65(62~76)岁和71(65~74)岁,中位PSA水平分别为15.11(6.63~42.86)ng/ml和12.31(7.94~18.25)ng/ml,差异均无统计学意义(P=0.334,P=0.448)。确诊前列腺癌后4周内均行18F-PSMA PET/CT检查。记录患者PET/CT检查主要病灶的最大标准化摄取值(SUVmax)和mpMRI检查主要病灶的最低表观弥散系数(ADCmin),并计算SUVmax/ADCmin比值,分析各参数与ISUP分级分组的相关性,比较不同级别分组的参数差异。通过受试者工作特征(ROC)曲线分析各参数对不同级别前列腺癌的诊断能力。结果本研究49例的ADCmin为(0.57±0.16)×10^(-3)mm^(2)/s,SUVmax为15.30±12.54,SUVmax/ADCmin比值为(29.69±23.72)×10^(3)。高级别组和低级别组的ADCmin分别为(0.54±0.20)×10^(-3)mm^(2)/s和(0.58±0.14)×10^(-3)mm^(2)/s,差异无统计学意义(P=0.411);SUVmax分别为21.97±14.83和12.36±10.30,SUVmax/ADCmin比值分别为(45.07±27.02)×10^(3)和(22.91±10.30)×10^(3),差异均有统计学意义(P=0.012,P=0.002)。SUVmax(r=0.501,P<0.001)和SUVmax/ADCmin比值(r=0.527,P<0.001)与ISUP分级分组呈正相关,ADCmin与ISUP分级分组呈负相关(r=-0.296,P=0.039)。ROC曲线结果显示,SUVmax/ADCmin比值、SUVmax、ADCmin的曲线下面积(AUC)分别为0.749、0.731、0.615。以SUVmax/ADCmin比值37.23×10^(3)为界值,诊断前列腺癌的敏感性和特异性分别为73.3%和85.3%。结论与单独应用PET/CT或mpMRI检查相比,联合18F-PSMA PET/CT和mpMRI检查的结果能够提高对前列腺癌的诊断效能。SUVmax/ADCmin比值与ISUP分级分组呈正相关,对于区分高低级别前列腺癌是有价值的诊断参数。

Objective To investigate the diagnostic value of the combination of 18F-prostate specific membrane antigen(PSMA)PET/CT and multiparametric magnetic resonance imaging(mpMRI)in identifying the grade group of prostate cancer,using parameters derived from the two imaging modalities.Method Prostate cancer patients diagnosed by histopathology and received 18F-PSMA PET/CT and mpMRI during September 2018 to May 2021 in our hospital were retrospectively studied.The median age was 68(64-75),with the median PSA level of 14.74(7.75-24.19)ng/mL.All patients received mpMRI before biopsy.On biopsy,6(12.2%)patients had International Society of Urological Pathology grade group(ISUP GG)1 diseases,16(32.7%)had ISUP GG 2 diseases,12(24.5%)had ISUP GG 3 diseases,and 15(10.9%)had ISUP GG 4 or 5 diseases.Patients were then divided into high-grade group(ISUP 4-5)and low-grade group(ISUP 1-3).The median age of patients in high-grade group and low-grade group were 65(62-76)and 71(65-74),respectively.The PSA level in high-grade group and low-grade group were 15.11(6.63-42.86)ng/ml and 12.31(7.94-18.25)ng/ml,respectively.No significant differences were found in age and PSA level between the two groups(P=0.334,P=0.448).All patients underwent 18F-PSMA PET/CT within 4 weeks after biopsy.The maximum standardized uptake value(SUVmax)and the minimum apparent diffusion coefficient(ADCmin)were recorded,and the ratio of SUVmax/ADCminwere calculated.The correlation between the above parameters and ISUP grade group were analyzed.The diagnostic value of the parameters was evaluated by the receiver operating characteristic(ROC)curve.Results The data of 49 patients were analyzed.The average ADCminwas(0.57±0.16)×10^(-3) mm^(2)/s,with the average SUVmax and SUVmax/ADCmin of 15.30±12.54 and(29.69±23.72)×10^(3),respectively.Statistical differences were found in SUVmax(P=0.012)and SUVmax/ADCmin(P=0.002)between the high-and low-grade groups,while ADCmin(P=0.411)showed no statistical differences between the two groups.Significant positive correlations were found between SUVmax(r=0.501,P<0.001),SUVmax/ADCmin(r=0.527,P<0.001)and ISUP grade group,respectively.There was a negative correlation between ADCmin and ISUP grade group(r=-0.296,P=0.039).SUVmax/ADCmin was the best index to distinguish high-grade group from low-grade group prostate cancer with the area under the curve(AUC)of 0.749.In contrast,the AUC of SUVmaxand ADCmin were 0.731 and 0.615,respectively.The diagnostic sensitivity and specificity of SUVmax/ADCmin were 73.3%and 85.3%,respectively,with a critical value of 37.23×10^(3).Conclusion The combination use of 18F-PSMA PET/CT and mpMRI could improve the diagnostic efficiency for prostate cancer,compared to either modality alone.The ratio of SUVmax/ADCmin has a positive correlation with ISUP grade group,and is a promising index for distinguishing the high-grade prostate cancer from low-grade cancer.