Complete resection of skull base meningiomas (SBMs) is often limited by their proximity to critical neurovascular structures, potentially increasing the risk of postoperative progression. This study quantified long-term progression risk after SBM resection, identified predictors of progression, and developed a data-driven MRI surveillance protocol using Bayesian methods.

Patients undergoing SBM resection between 2002 and 2020 at two neurosurgical centres were analysed. Kaplan–Meier and Cox regression analyses were used to estimate intervention-free survival (IFS). Conditional probability modelling was used to derive an MRI surveillance schedule that maintained a ≤ 3% risk of progression requiring intervention, stratified by extent of resection.

A total of 358 SBMs were included. Median age at diagnosis was 57 years (IQR 18), and 76.0% of patients were female. WHO Grade 1 tumours accounted for 80.3% of cases and Grade 2 for 19.7%. Median follow-up was 97 months (IQR 64–128). Progression requiring re-intervention occurred in 14.1% of patients. Subtotal resection (STR) increased the risk of re-intervention (HR 2.62, 95% CI 1.30–5.30, p = 0.009), whereas higher comorbidity burden (HR 0.78, 95% CI 0.62–0.98, p = 0.038) and incidental presentation (HR 0.11, 95% CI 0.01–0.88, p = 0.038) were associated with lower risk. Conditional probability modelling demonstrated higher annual progression risk following STR, supporting more intensive imaging surveillance. Recommended MRI schedules were: gross total resection (GTR), scans at 3 months, 2, 5, 8, and 10 years; STR, scans at 3 months, 1 year, 18 months, annually from years 2–8, and at 10 years.