Marieke van Son

149 PREDICTION MODELS FOR BF AFTER FOCAL SALVAGE HDR-BT Figure 3 – Nomogram based on model 2 for prediction of biochemical failure among patients who underwent FS-HDR-BT. Probabilities of biochemical failure within 12, 24, and 36 months can be calculated. The model can be used online through: https://fs-hdr-bt-prediction.shinyapps.io/ model2/. As an example, for the same patient (72 years old, PSA-level 6.0 ng/ml, and a pre-salvage PSADT of 25 months) with no seminal vesicle involvement, PSA nadir after 6 months and a PSA reduction of 90%, the score based on model 2 would be 313, with estimated bDFS probabilities of 98% (95% CI: 96-100%), 80% (95% CI: 71-91%) and 52% (95% CI: 36-74%) at 12, 24, and 36 months. Figure 4 – Kaplan-Meier plots for biochemical disease-free survival for low-, intermediate-, and high-risk groups (based on linear predictor/nomogram score), as identified by model 1 (left, nomo- gram sum scores <193, 193-222, and >222, respectively) and model 2 (right, nomogram sum scores <297, 297-334, and >334, respectively). Scores are as calculated by the respective nomograms. 8