Adjuvant Radiotherapy in Grade II, Atypical Meningioma of the Skull Base

Abstract

Introduction Atypical meningiomas (AM) are meningiomas that are more aggressive than their grade-I counterparts and have a higher rate of recurrence. The effect of adjuvant radiotherapy (ART) on AM of the skull base is not defined. Methods A retrospective review of all AM's of the skull base primarily resected at our institution from 1996 to 2018 was completed. ART was defined as radiotherapy (RT) that occurred within 6 months of initial resection, regardless of Simpson's grade. Minimum time length of follow-up after resection was 2 years. Statistical analysis was performed using SAS. Results There were a total of 59 skull base–located (SBL) AMs resected at our institution from 1996 to 2018. The average age of our cohort was 53.2 years. Gross total resection, defined as Simpson's grades I to III resection, was achieved in 36 (61%) of cases. Thirty-five of 59 (59%) patients received ART. Recurrence was observed in 14 patients (24%), and mean time to recurrence was 63.8 months. Patients who received ART had a lower observed rate of recurrence (8 vs. 46%); however, time to recurrence was not significantly different between the two populations. Conclusion We observe that AM in the skull base location have higher recurrence rates than we would expect from grade-I meningioma. These data suggest that ART may offer benefit to the overall observed frequency of recurrence of SBL AM; however, the time to recurrence between patients who received ART and those who did not was not statistically significant in survival analysis.

Targeted gene expression profiling predicts meningioma outcomes and radiotherapy responses

“…Current indications for postoperative radiotherapy for patients with meningiomas are controversial, particularly for patients with primary WHO grade 2 meningiomas who are randomized to postoperative surveillance or postoperative radiotherapy on NRG BN-003 and EORTC 1308 after GTR 3,6 . Con icting retrospective series have variably reported a bene t 9,[41][42][43][44][45][46][47][48] or no bene t from radiotherapy in this setting 47,[49][50][51][52][53][54][55][56] , which has fueled debate and inspired these international Phase III clinical trials of radiotherapy for patients with meningiomas. The gene expression biomarker reported here improves risk strati cation for primary WHO grade 2 meningiomas and may identify favorable WHO grade 2 meningiomas where postoperative radiotherapy could be safely omitted in favor of close surveillance.…”

The Impact of Social Determinants on Receipt of Adjuvant Radiation Nationally Following Atypical Meningioma Surgery

“…This is due to changes in grading of meningiomas, most notably including "brain invasion" as a primary grading criterion [6]. AMs have recurrence rate of up to 48% in 10 years [7], so many institutions have advocated for adjuvant radiotherapy (ART) after attempted gross total resection (GTR) [8,9]. A growing body of evidence suggests that ART prolongs overall survival and reduces the likelihood of local recurrence [10,11].…”