Gamma knife radiosurgery versus radiotherapy for primary optic nerve sheath meningioma: outcomes, and prognostic factors.
Author: Shang-Te Ma
Base Hospital / Institution: 1. Taipei Medical University- ShuangHo Hospital; 2. Samsung Medical Center
Rapid fire oral presentation
Abstract ID: 24-294
Purpose
Primary optic nerve sheath meningioma (ONSM) is a benign tumor that stems from the growth of menigoepithelial cells lining the optic nerve sheath. Vision impairment can develop in >85% of patients. Herein, we compared the outcomes, complications and prognostic factors for primary ONSM treated with either gamma knife radiosurgery (GKRS) or radiotherapy.
Methods
We performed a 20-year retrospective cohort study from January 2004 to October 2023. Patients with primary ONSM treated with either GKRS or radiotherapy were included. Patient demographics, pre- and post-treatment examination results, tumor features in orbital magnetic resonance imaging, and post-treatment complications were collected and analyzed.
Results
There were 25 patients receiving GKRS and 10 patients receiving radiotherapy in our cohort study, respectively. Intracranial extension of the tumor was noted in 11 patients (9 for GKRS and 2 for radiotherapy). Stable post-treatment vision was achieved in 64% patients after GKRS and 70% patients after radiotherapy (p > 0.99), respectively. Ninety-six percent (n = 24) in GKRS group and 100% (n = 10) had successful tumor local control. The median shrinkage ratios of gross tumor volume (GTV) were 41% and 29% in GKRS and radiotherapy groups, respectively (p = 0.57). Post-treatment cataract was noted in 12.5% (3 of 24) patients in GKRS group and 20% (2 of 10) in radiotherapy group (p = 0.618). Only 2 patients had post-treatment radiation retinopathy: a stage 1 patient (4.0%) after GKRS and a stage 3 patient (10.0%) after radiotherapy (p = 0.496). Among the clinical and imaging features, pre-treatment visual acuity (p <0.01), post-treatment GTV (p = 0.03) and intracranial extension (p = 0.049) were significantly correlated with final visual outcomes.
Conclusion
This is the first single-center study providing a direct comparison of GKRS and radiotherapy for primary ONSM. Treatment outcomes and complications were similar for both modalities. Poor visual prognosis is anticipated in patients with worse pre-treatment vision, larger post-treatment GTV, and intracranial extension.
Additional Authors
| First name | Last name | Base Hospital / Institution |
|---|---|---|
| Kyung In | Woo | 1. Taipei Medical University- ShuangHo Hospital; 2. Samsung Medical Center |
