Personalized prediction of local control after stereotactic radiosurgery for craniopharyngioma: a multicenter machine
Jheremy S Reyes1, Constantinos G Hadjipanayis1, Kenneth Bernstein2
1Center for Image-Guided Neurosurgery, Department of Neurological Surgery, University of Pittsburgh Medical Center (UPMC), Pittsburgh, PA, USA.
Background:
Stereotactic radiosurgery (SRS) is used in selected patients with craniopharyngioma, yet counseling and follow-up planning often rely on population-level local control rates rather than individualized expectations over time.
Objective:
To develop and internally validate a multicenter survival model to predict imaging-defined time to progression after SRS for craniopharyngioma.
Methods:
We analyzed a multicenter IRRF registry of SRS-treated craniopharyngioma patients. Imaging progression was defined by the overall last imaging response (PD vs. non-PD), with censoring at last imaging follow-up when progression was not observed. A Random Survival Forest (RSF) model was evaluated using 5-fold out-of-fold cross-validation. Performance was assessed using the concordance index, time-dependent AUC at 12, 24, and 60 months with bootstrap 95% confidence intervals, integrated Brier score (IBS) over 0-60 months, and risk-stratified calibration. Benchmarks included a penalized Cox model and a Kaplan-Meier baseline.
Results:
Among 277 patients (event rate 13.0%; median imaging follow-up 57.0 months by reverse Kaplan-Meier), RSF achieved an out-of-fold C-index of 0.905. Time-dependent AUC was 0.895 (95% CI 0.828-0.959) at 12 months, 0.897 (95% CI 0.833-0.952) at 24 months, and 0.934 (95% CI 0.889-0.969) at 60 months. IBS (0-60 months) was 0.050 with favorable calibration.
Conclusions:
A multicenter machine learning survival model can provide individualized, well-calibrated estimates of local control over time after SRS for craniopharyngioma to support non-prescriptive decision support.
Clinical Trial Number:
Not applicable.
