Sensitivity analysis of dose-response model parameters for the bladder in prostate cancer radiotherapy.

Puri, Tanuj; Talbot, Christopher; Farcy-Jacquet, Marie-Pierre; Seibold, Petra; Veldeman, Liv; Kerns, Sarah; Sperk, Elena; Avuzzi, Barbara; Hoskin, Peter; Azria, David; Dunning, Alison; van Herk, Marcel; Rancati, Tiziana; Lambrecht, Maarten; Webb, Adam; Osorio, Eliana Vasquez; Chang-Claude, Jenny; West, Catharine; Rosenstein, Barry; Choudhury, Ananya; McWilliam, Alan; Vega, Ana; de Ruysscher, Dirk; Consortium, REQUITE

doi:10.1016/j.ejmp.2025.105178

Journal Article

DKFZ-2025-02087

Sensitivity analysis of dose-response model parameters for the bladder in prostate cancer radiotherapy.

Puri, T. ; Rancati, T. ; Seibold, P.DKFZ* ; Webb, A. ; Osorio, E. V. ; Azria, D. ; Farcy-Jacquet, M.-P. ; Chang-Claude, J.DKFZ* ; Dunning, A. ; Lambrecht, M. ; Avuzzi, B. ; de Ruysscher, D. ; Sperk, E. ; Vega, A. ; Veldeman, L. ; Rosenstein, B. ; Kerns, S. ; Talbot, C. ; McWilliam, A. ; Hoskin, P. ; Choudhury, A. ; West, C. ; van Herk, M. ; Consortium, R. (Collaboration Author)

2025
Elsevier Amsterdam

Physica medica 139, 105178 (2025) [10.1016/j.ejmp.2025.105178]

This record in other databases:

Please use a persistent id in citations: doi:10.1016/j.ejmp.2025.105178

Abstract: This study evaluates how model parameter values affect dose-response maps (DRMs) in identifying high-risk bladder subregions associated with late urinary toxicities in prostate cancer patients post-radiotherapy.Data from 1808 patients were analyzed for five late bladder toxicities. Baseline scores were subtracted from maximum toxicity at 12 and 24 months and dichotomized into grades ≥ 1 and ≥ 2. Bladders were segmented on computed tomography scans, and dose-surface maps (DSMs) were created on 91 × 90 voxel grids using spherical and cylindrical coordinates. Voxel doses were converted to equivalent dose in 2 Gy fractions (EQD2, α/β 1-3 Gy). Welch's t and Mann-Whitney U equations were applied at each voxel location. Multiple comparisons were corrected via permutation testing (10-10000 iterations), and statistically significant voxels were identified using the 90th and 95th percentiles of Tmax/Umax. Sensitivity of parameters was assessed by varying one parameter at a time, with changes > 400 voxels (∼5% of 8190) classified as large and ≤ 400 as small.Urinary tract obstruction was the only toxicity significantly associated with bladder DSMs, focusing results on this outcome. After baseline adjustment and dichotomization, event/nonevent counts were 62/701 (grade≥1) and 21/742 (grade≥2; N = 763). DRM results showed large effects of toxicity grade threshold, coordinate system, statistical test equation, and Tmax/Umax thresholding. EQD2 α/β showed variable effects, large for cylindrical and small for spherical coordinates, while the number of permutations had only a small effect.Parameter selection significantly influences high-risk subregion identification in DRMs, emphasizing the need for standardized parameter reporting for meaningful external comparisons.

Keyword(s): Bladder ; IBDM ; Image-based data mining ; Imaging biomarker ; Multicenter clinical trial ; OAR ; Organ-at-risk ; Prediction model ; Predictive modeling ; Prostate cancer ; Radiotherapy ; Standardization ; Toxicity ; VBA ; Voxel-based dose–response analysis