Study evaluates long-term outcomes of gamma knife radiosurgery in patients with grade 2 meningiomas

Background and objectives

The role of radiosurgery in the treatment of grade 2 meningioma remains unclear. This study aimed to evaluate the long-term outcomes of gamma knife radiosurgery (GKRS) in patients with grade 2 meningiomas and to identify factors influencing tumor control and survival.

Methods

In this retrospective study, seventy patients underwent GKRS for grade 2 meningioma between 2007 and 2016. Tumor recurrence was categorized as local, marginal, or distant. Survival curves were estimated using the Kaplan-Meier method, while the log-rank test and Cox proportional hazards model were employed to analyze potential risk factors.

Results

The median follow-up period was 48 months (range: 8 to 132 months). The one-year, three-year, and five-year local control rates were 92%, 73%, and 65%, respectively. The one-, three-, and three-year progression-free survival rates were 87%, 51%, and 44%, respectively. Multiple lesions and multiple prior recurrences were identified as negative predictors of marginal control and progression-free survival. Similarly, multiple lesions and marginal doses ≤13 Gy were associated with poor local control. Serious complications related to gamma knife use occurred in 4% of patients.

Conclusions

Our results support the use of GKRS as a reasonable treatment option in the management of grade 2 meningiomas. A higher margin dose should be considered to achieve better local control. Outfield progression (marginal and/or distant recurrence) was common, particularly in patients with multiple prior recurrences and/or multiple lesions. More aggressive treatment strategies should be explored for patients with these risk factors.