Fig. 3.

Local regression nonparametric smoothing (calibration) plot of the compact (a) and comprehensive (b) prediction model showing the relationship between nomogram predictions and observed frequency of positive ⁶⁸Ga-PSMA-11-ligand PET/CT examinations in the validation cohort. Perfect or ideal predictions correspond to the 45° line (grey line). Points situated above the 45° line correspond to overprediction in the validation cohort in comparison to the prediction model, whereas points estimated below the 45° line correspond to underestimation in the validation cohort according to the prediction model (dotted black line). Vertical lines indicate the frequency distribution of predicted probabilities