Timo F W Soeterik1, Harm H E van Melick2, Lea M Dijksman3, Heidi V N Küsters-Vandevelde4, Douwe H Biesma3, J A Witjes5, Jean-Paul A van Basten6. 1. Department of Value-Based Healthcare, Santeon-group, Utrecht, The Netherlands; Department of Urology, St. Antonius Hospital, Santeon-group, Nieuwegein, The Netherlands. Electronic address: t.soeterik@antoniusziekenhuis.nl. 2. Department of Urology, St. Antonius Hospital, Santeon-group, Nieuwegein, The Netherlands. 3. Department of Value-Based Healthcare, St. Antonius Hospital, Santeon-group, Nieuwegein/Utrecht, The Netherlands. 4. Department of Pathology, Canisius Wilhelmina Hospital, Santeon-group, Nijmegen, The Netherlands. 5. Department of Urology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands. 6. Department of Urology, Canisius Wilhelmina Hospital, Santeon-group, Nijmegen, The Netherlands.
Abstract
INTRODUCTION: To establish oncological safe nerve-sparing robot-assisted radical prostatectomy, accurate assessment of extraprostatic extension (EPE) is critical. A recently developed nomogram including magnetic resonance imaging parameters accurately predicted side-specific EPE in the development cohort. The aim of this study is to assess this model's performance in an external patient population. PATIENTS AND METHODS: Model fit was assessed in a cohort of 550 patients who underwent robot-assisted radical prostatectomy in 2014 to 2017 for prostate cancer. Model calibration was evaluated using calibration slopes. Discriminative ability was quantified using the area under the receiver operating characteristic curve. Model updating was done by adjusting the linear predictor to minimize differences in expected and observed risk for EPE. RESULTS: A total of 792 prostate lobes were included for model validation. Discriminative ability expressed in terms of receiver operating characteristic curve was 0.78, 95%CI 0.75-0.82. Graphical evaluation of the calibration showed poor fit with a high disagreement between predicted probabilities and observed probabilities of EPE in the population. Model updating resulted in excellent agreement between mean predicted and observed probabilities. However, calibration plots showed substantial miscalibration; including both under- and overestimation. CONCLUSION: External validation of the novel nomogram for the prediction of side specific EPE developed by Martini and co-workers showed good discriminative ability but poor calibration. After updating, substantial miscalibration was still present. Use of this nomogram for individualized risk predictions is therefore not recommended.
INTRODUCTION: To establish oncological safe nerve-sparing robot-assisted radical prostatectomy, accurate assessment of extraprostatic extension (EPE) is critical. A recently developed nomogram including magnetic resonance imaging parameters accurately predicted side-specific EPE in the development cohort. The aim of this study is to assess this model's performance in an external patient population. PATIENTS AND METHODS: Model fit was assessed in a cohort of 550 patients who underwent robot-assisted radical prostatectomy in 2014 to 2017 for prostate cancer. Model calibration was evaluated using calibration slopes. Discriminative ability was quantified using the area under the receiver operating characteristic curve. Model updating was done by adjusting the linear predictor to minimize differences in expected and observed risk for EPE. RESULTS: A total of 792 prostate lobes were included for model validation. Discriminative ability expressed in terms of receiver operating characteristic curve was 0.78, 95%CI 0.75-0.82. Graphical evaluation of the calibration showed poor fit with a high disagreement between predicted probabilities and observed probabilities of EPE in the population. Model updating resulted in excellent agreement between mean predicted and observed probabilities. However, calibration plots showed substantial miscalibration; including both under- and overestimation. CONCLUSION: External validation of the novel nomogram for the prediction of side specific EPE developed by Martini and co-workers showed good discriminative ability but poor calibration. After updating, substantial miscalibration was still present. Use of this nomogram for individualized risk predictions is therefore not recommended.
Authors: Jethro C C Kwong; Adree Khondker; Christopher Tran; Emily Evans; Adrian I Cozma; Ashkan Javidan; Amna Ali; Munir Jamal; Thomas Short; Frank Papanikolaou; John R Srigley; Benjamin Fine; Andrew Feifer Journal: Can Urol Assoc J Date: 2022-06 Impact factor: 2.052
Authors: André N Vis; Roderick C N van den Bergh; Henk G van der Poel; Alexander Mottrie; Philip D Stricker; Marcus Graefen; Vipul Patel; Bernardo Rocco; Birgit Lissenberg-Witte; Pim J van Leeuwen Journal: BJUI Compass Date: 2021-11-09
Authors: Clara Humke; Benedikt Hoeh; Felix Preisser; Mike Wenzel; Maria N Welte; Lena Theissen; Boris Bodelle; Jens Koellermann; Thomas Steuber; Alexander Haese; Frederik Roos; Luis Alex Kluth; Andreas Becker; Felix K H Chun; Philipp Mandel Journal: Curr Oncol Date: 2022-03-28 Impact factor: 3.109