Single-Fraction Stereotactic Radiosurgery as Primary Management of Sporadic Meningiomas: A 25-Year Cohort Study

Neurosurgery 97:1267–1274, 2025

This study reports long-term outcomes of single‑fraction Gamma Knife stereotactic radiosurgery (SRS) as primary treatment for 653 sporadic intracranial meningiomas in 616 patients over a 25‑year period. With median margin dose 15 Gy and median imaging follow-up 6.3 years, progression‑free survival was excellent (99.8% at 5 years, 99.0% at 10 years), and raw tumor control reached 98.6%.

Treatment‑related neurological sequelae were uncommon (1.8% permanent/intervention), though larger tumor volume, higher V12, and greater number of isocenters increased complication risk. The authors conclude single‑fraction SRS at studied doses offers high long‑term control for small‑to‑medium sporadic meningiomas, emphasizing careful patient selection.

Stereotactic Radiosurgery (SRS) Effectiveness: Single-fraction SRS is highly effective as a primary treatment for sporadic, small- to medium-volume intracranial meningiomas, achieving a 99% tumor control rate at 10 years and 93% at 15 years progression-free survival (PFS).

Low Permanent Morbidity: The risk of permanent treatment-related neurological complications is low (1.8%), with most side effects being temporary or minor.

Key Predictors of Outcome: Larger tumor volume is the main predictor of both tumor progression and treatment-related complications, emphasizing the importance of patient selection for SRS.

Radiosurgical Parameters: Increased number of isocenters, higher 12-Gy volume (V12), larger tumor volume, and lower maximal dose are associated with higher risk of treatment-related complications.

Comparison to Observation: SRS provides superior tumor control compared to observation in patients with incidentally discovered, asymptomatic meningiomas, with similar rates of new neurological deficits.

Radiation Dose Recommendations: A median margin dose of 13–15 Gy balances long-term tumor control and risk of complications; doses below 12 Gy may increase recurrence risk, while higher doses increase morbidity.

Biological Effective Dose (BED): In this cohort, higher BED was not predictive of improved PFS, likely due to the already high dosing protocol; however, other studies suggest BED can be a useful predictor when a wider dose range is used.

Limitations: The study is retrospective and single-institution, with potential selection bias and incomplete follow-up; findings may not generalize to syndromic or radiation-induced meningiomas.