Linac-based fractionated stereotactic radiosurgery for high-risk meningioma
Rahul N Prasad, John C Breneman, Timothy Struve, Ronald E Warnick and Luke E. Pater
Purpose: Single-fraction stereotactic radiosurgery (SRS) for meningioma has high rates of symptomatic perilesional edema in some settings. Fractionated stereotactic radiosurgery (fSRS) could decrease edema rates while maintaining tumor control.
Methods and materials: Patients at an institution were retrospectively reviewed (2013-2017). Adults receiving definitive, linear accelerator (linac)-based fSRS (25-30Gy/5 fractions) were included. fSRS was recommended for tumors at high risk for perilesional edema with SRS due to large size, prior irradiation, or proximity to organs at risk. Endpoints included rates of symptomatic, radiographically-defined perilesional edema and local control (LC).
Results: 12 Patients with 13 meningiomas met criteria. 24-month actuarial LC and overall survival were 87% and 100%. Symptomatic, post-treatment edema was identified on follow-up MRI in 31% of cases. No variables predicted edema, but affected lesions were larger (6.82 v. 2.46cc).
Conclusion: Linac-based fSRS for meningioma has high local control and modest toxicity rates similar to SRS in the literature. Prospective studies comparing fSRS/SRS are warranted.
Keywords: meningioma, fractionated stereotactic radiosurgery, linear accelerated-based, perilesional edema, local control