| Part I The Diagnosis Performance of Prostate Imaging Reporting and Data System Version 1 and 2 in Detection of Prostate Cancer in Transition ZoneObjectives:To evaluate the Prostate Imaging Reporting and Data System Version 1(PI-RADS V1)and Version 2(PI-RADS V2)for detection of prostate cancer(PCa)in the transition zone(TZ).Methods:Sixty-three patients with suspicious lesions in TZ on mpMRI were scored according to the PI-RADS system(V1 and V2)before MR/TRUS fusion guided biopsy prospectively.In all of the patients with suspicious tumors,respectively at least one lesion with a PI-RADS V1 assessment category of ?3,was selected for biopsy.Independent sample t test was used to compare scores of PI-RADS V1 and V2 between PCa and BHP.The diagnostic performance of PI-RADS V1 and V2 for detection of PCa in the transition zone was compared by analyzing receiver operating characteristics(ROC)basing on the results of MR/TRUS fusion guided biopsy.Results :A cohort of 63 patients was performed including 30 cases of PCa(31 cores)and 33 cases of benign prostatic hyperplasia(BPH)(36 cores).PCa(V1: 11.7±2.2;V2: 4.1±0.9)had significantly higher scores of both PI-RADS V1 and PI-RADS V2 than BHP(V1: 8.2±2.5;V2: 2.5±0.9)(p<0.05).Using a PI-RADS V1 score cut-off ? 9,sensitivity and specificity in group PCa and BPH were calculated,which were 83.87% and 72.22% with a AUC of 0.851;using a PI-RADS V2 score cut-off ? 4,which were 74.19% and 86.11% with a AUC of 0.882,respectively.Conclusions: PI-RADS V2 performed better than V1 for the assessment of prostate cancer in TZ.Part II Histogram Analysis of monoexponential DWI,biexponential IVIM model and PI-RADS V2 for the Differentiation of Prostate Cancer from BPH in the Transition zoneObjective :To evaluate histogram analysis of ADC,intravoxel incoherent motion(IVIM)and PI-RADS V2 for detecting the prostate cancer(PCa)in the transition zone(TZ).Methods :A total of 63 patients underwent preoperative DW-MRI(b of 0-1000 s/mm2)were prospectively collected and processed by monoexponential and biexponential IVIM model for quantitation of apparent diffusion coefficients(ADCs),diffusivity(D)and pseudo-diffusivity(D*)and perfusion fraction(f).Histogram analysis was performed by outlining entire-tumor regions of interest(ROIs).These parameters(separately and combined in a logistic regression model)were used to differentiate lesions depending on histopathological analysis of magnetic resonance/transrectal ultrasound(MR/TRUS)fusion guided biopsy.The diagnostic ability of differentiating the PCa from BHP in TZ was analyzed by ROC regression.The correlations between the Histogram analysis of quantitative parameters and Gleason score were assessed with Spearman correlation.Results:Thirty(31 focus)cases of PCa in PZ and 33(36 focus)cases of BPH were confirmed by pathology.Mean ADC,median ADC,10 th percentile ADC,90 th percentile ADC,kurtosis,skewness of ADC,mean D and median D differed significantly between PCa and BHP in TZ.The highest classification accuracy was achieved by the mean ADC(0.841)and mean D(0.809).A logistic regression model based on mean ADC and mean D led to an AUC of 0.873,however,the difference is not significant;the AUC of the combination of mean ADC and PI-RADS is significant higher the any single parameters.There were 7 Gleason 6 areas,9 Gleason 7 areas,8 Gleason 8 areas,5 Gleason 9 areas and 2 Gleason 10 areas detected from the 31 prostate cancer areas,the mean Gleason value was(7.5±1.2).The mean ADC,mean D and PI-RADS V2 had correlation with Gleason score(r=-0.522,r=-0.407 and r=0.564;respectively,P<0.05).Conclusion:1.Monoexponential DWI and biexponential IVIM could potentially improve the differentiation of prostate cancer in TZ;2.IVIM did not perform better than the parameters alone significantly,however,its diagnostic performance was significantly improved by the addition of mean ADC and PIRADS V2 in the diagnosis of PCa in TZ;3.It is feasible to stratify the pathological grade of prostate cancer in TZ by mean ADC,mean D and PI-RADS V2 respectively. |
PDF Full Text Request