The extent of resection has been shown to improve outcomes in patients with meningiomas. However, resection can be complicated by constraining local anatomy, leading to subtotal resections. An understanding of the natural history of residual tumors is necessary to better guide postsurgical management and minimize recurrence. This study seeks to identify predictors of recurrence and high growth rate following subtotal resection of intracranial meningiomas.
Adult patients who underwent primary surgical resection of a WHO grade I meningioma at a tertiary care institution from 2007–2017 were retrospectively reviewed. Volumetric tumor measurements were made on patients with subtotal resections. Stepwise multivariate proportional hazards regression analyses were performed to identify factors associated with time to recurrence, as well as stepwise multivariate regression analyses to assess for factors associated with high postoperative growth rate.
Of the 141 patients (18%) who underwent radiographic subtotal resection of an intracranial meningioma during the reviewed period, 74 (52%) suffered a recurrence, in which the median (interquartile range, IQR) time to recurrence was 14 (IQR 6–34) months. Among those tumors subtotally resected, the median pre- and postoperative tumor volumes were 17.19 cm3 (IQR 7.47–38.43 cm3) and 2.31 cm3 (IQR 0.98–5.16 cm3), which corresponded to a percentage resection of 82% (IQR 68%–93%). Postoperatively, the median growth rate was 0.09 cm3/year (IQR 0–1.39 cm3/year). Factors associated with recurrence in multivariate analysis included preoperative tumor volume (hazard ratio [HR] 4.720, 95% confidence interval [CI] 1.042–3.146, p = 0.008), falcine location (HR 2.215, 95% CI 1.179–4.161, p = 0 0.021), tentorial location (HR 2.410, 95% CI 1.203–4.829, p = 0.024), and African American race (HR 1.811, 95% CI 1.042–3.146, p = 0.044). Residual volume (RV) was associated with high absolute annual growth rate (odds ratio [OR] 1.175, 95% CI 1.078–1.280, p < 0.0001), with the maximum RV benefit at < 5 cm3 (OR 4.056, 95% CI 1.675–9.822, p = 0.002).
By identifying predictors of recurrence and growth rate, this study helps identify potential patients with a high chance of recurrence following subtotal resection, which are those with large preoperative tumor volume, falcine location, tentorial location, and African American race. Higher RVs were associated with tumors with higher postoperative growth rates. Recurrences typically occurred 14 months after surgery.