Statistical Analysis
The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (PLR), negative likelihood ratio (NLR), and the accuracy of mpMRI,68Ga-PSMA PET/MRI, and combined imaging for the detection of the index tumour were calculated by creating crosstabs. Correlations between continuous measures were determined using Spearman’s (rs) correlation. The Cohen’s kappa coefficient (κ) was calculated to define agreement between mpMRI and 68(Ga)-PSMA PET/MRI. The cut-off values of clinical parameters were determined by using receiver operating characteristics (ROC) curve analysis and Youden’s index. Diagnostic accuracy of imaging modalities was assessed using the area under the curve (AUC), and 95% confidence intervals (95% CI) were calculated by ROC analysis. Combined imaging was also added to the ROC analysis as a third method. Accordingly, if either imaging modalities were positive, then the combined imaging was considered positive, and if both imaging modalities were negative, then the combined imaging considered negative. Differences in the sensitivity and specificity of mpMRI and 68Ga-PSMA PET/MRI were analysed using the McNemar test. A significance level of 5% was used. All analyses were performed using SPSS software, version 15.0 (SPSS Inc., Chicago, IL, USA).