NCMP-17. IMPROVEMENT IN CRANIAL NEUROPATHIES FOLLOWING STEREOTACTIC RADIOTHERAPY ALONE FOR SKULL BASE MENINGIOMAS

Abstract

Abstract Cranial neuropathies are a common presenting symptom in skull base meningiomas. Many of these tumors are not amenable to surgical resection; for these patients, stereotactic radiotherapy (SRT) is a viable option. Our study sought to investigate the efficacy of SRT for improving cranial neuropathies and identify predictors that portend favorable response. A single-institution retrospective analysis was performed for patients with skull base meningiomas causing cranial neuropathies who received SRT as sole treatment from 2001 to 2021. Clinical variables were collected and analyzed for predictors of improvement. Subgroup analysis for each type of cranial neuropathy was also performed. Overall 101 patients were included, of which 51 (50.4%) had an improvement in cranial neuropathy following SRT. There was no difference in gender or age between patients with and without improvement. The most common tumor location was cerebellopontine angle (n=38), followed by cavernous sinus (n=27) and optic canal (n=25). Cranial nerve II was most frequently affected (n=34), followed by VI (n=28) and V (n=27). There was no significant difference in tumor volume, radiation dose, location, or specific cranial nerve affected between patients with and without improvement. Median time to improvement was 8 months (IQR 3-15). In subgroup analysis, patients with optic neuropathy who experienced improvement after SRT were significantly younger (50.7 vs. 60.1 years, p=0.03), while patients with trigeminal neuropathy who experienced improvement were significantly older (69.6 vs. 58.7 years, p=0.03). For patients with extraocular movement neuropathies or vestibulocochlear dysfunction, there were no significant factors associated with improvement. Half of patients with cranial neuropathy from skull base meningiomas experience symptomatic improvement following sole SRT. Age may play a role in predicting improvement, with younger patients more likely to have improved vision and older patients more likely to experience improvement in trigeminal neuropathy.