Repeated stereotactic radiosurgery for high grade meningioma

Atypical and anaplastic meningioma (World Health organization [WHO] Grades II and III) present therapeutic challenges due to their aggressive behavior and high risk of recurrence. This study addressed the lack of data related to the effectiveness and safety of repeated stereotactic radiosurgery (SRS) in managing high-grade recurrent or residual meningioma.

This study analyzed data extracted from the medical records of 112 patients (mean age of 57.9 years) who underwent SRS for recurrent or residual high-grade meningioma between January 2002 and December 2022. The data included clinicodemographic profiles, treatment parameters, and imaging phenotypes. The average follow-up duration was 41.7 months (range 12-160.7 months).

There was slight preponderance of females in the cohort (65:47). All patients had undergone craniotomy and histopathologic confirmation of atypical or anaplastic meningioma. Gross tumor resection was achieved in 35 cases. Atypical meningioma accounted for the vast majority of cases (105; 93.8%) with only 7 cases of anaplastic meningioma (6.2%). At a median follow-up of 41.7 months after SRS, tumor control was achieved in 29.5% of cases. Kaplan-Meier analysis indicated overall actuarial progression free survival rates of 79.5%, 43.8% and 30.4% at 1, 3 and 5 years after radiosurgery, respectively. In cases involving repeated SRS, these rates were 97.6%, 69% and 45.2%, respectively. Male sex, older age, anaplastic phenotype, subtotal resection, and larger tumor volume were significantly predictive of tumor growth after treatment. Adverse radiation effects were observed in 33.8% of patients who underwent repeated SRS. Most of those patients were asymptomatic and only five patients required a temporary course of steroid therapy.

Our data suggest that SRS is a relatively safe and effective treatment option for recurrent or residual high-grade meningioma, with an acceptable complication profile, even when performed repeatedly. Anaplastic tumor phenotype, subtotal resection, and larger tumor volume were factors associated with tumor growth, warranting close clinical surveillance after radiosurgery.