Fig. 1.

Calibration curves for the compact nomogram of Rauscher et al [4] (nomogram 1) predicting the probability of positive prostate-specific membrane antigen–based positron emission tomography/computed tomography and the nomogram of Luiting et al [5] (nomogram 2) predicting the probability of detecting prostate cancer recurrence outside the prostatic fossa. Discrimination was quantified in terms of the area under the receiver operating characteristic curve. Calibration was quantified via calibration-in-the-large and the calibration slope. The red line denotes perfect prediction (predicted probability is equal to observed proportion). The black line denotes to the actual observed proportion as a function of the predicted probability. When the black line is below the red line, the nomogram gives an overprediction. When the black line is above the red line, the observed proportion is higher than the predicted probability. The gray area denotes the 95% confidence interval (CI) of the flexible calibration. Vertical inset lines indicate the frequency distribution of predicted probabilities and if there were either positive findings/showed metastasis (marked as 1) or negative findings/showed no metastasis (marked as 0).