Fractionated Radiotherapy With Stereotactic Radiosurgery Boost Controls Gross Disease in Grade 2 Meningioma.

Area of Science:

• Neuro-oncology
• Radiation Oncology
• Neurosurgery

Background:

• Grade 2 meningiomas often recur after maximal surgical resection and fractionated radiotherapy (RT).
• Improved local control rates are needed for these challenging tumors.
• Dose escalation strategies are being explored to enhance treatment efficacy.

Purpose of the Study:

• To evaluate a dose escalation strategy using a stereotactic radiosurgery (SRS) boost added to fractionated RT for grade 2 meningioma.
• To assess local disease control and adverse events in patients treated with this combined modality approach.

Main Methods:

• Retrospective analysis of 14 patients with grade 2 meningioma treated between 2009-2023.
• All patients received surgical resection, fractionated RT, and an SRS boost targeting gross disease.
• Evaluation of local control, progression-free survival, overall survival, and adverse events (AEs).

Main Results:

• Median follow-up was 34 months; 18-month progression-free survival was 92.3% and overall survival was 100%.
• Three patients (23%) experienced treatment failures, none within the SRS volume.
• High-grade AEs (grade ≥3) occurred in 23% of patients, including radiation necrosis and cognitive decline.

Conclusions:

• An SRS boost to fractionated RT achieved 100% in-field local control at 3 years for grade 2 meningioma.
• This dose escalation strategy demonstrates an acceptable toxicity profile.
• The findings suggest SRS boost is a potentially effective and improved adjuvant treatment for grade 2 meningioma.