Abstract TP229: Stroke Rate and Associated Factors in Individuals With Primary Brain Gliomas and Brain Radiation Therapy: A Retrospective Cohort Study

Abstract

Background/Objectives: The risk of stroke in individuals with brain gliomas may be increased due to several possible factors including chemotherapy, radiation-induced toxicity, and concomitant vascular risks. We report on the stroke rate and associated factors following brain tumor diagnosis and radiation therapy. Design: This is a retrospective cohort study, from a single tertiary academic brain tumor center, of patients with brain gliomas diagnosed between 2004-2021 who received brain radiation therapy during their treatment. Chi-square test was used to calculate the odds ratios. Results: Among a total of 912 patients with primary gliomas who received radiation therapy, stroke subsequently occurred in 93 patients (10.2%). Strokes were ischemic in 72.0% (N=67), intracerebral hemorrhage (ICH) in 25.8% (N=24), and subarachnoid hemorrhage in 2.2% (N=2). Individuals who sustained a stroke were 44.1% female and had a mean age of 54.2 years (range 21-84) at the time of stroke diagnosis. Of those who had a stroke, 64.5% (N=60) were also taking bevacizumab at the time of stroke. Median time from initiation of radiation therapy to stroke was 653 days (range 0-3788). Median radiation dose was 5940 cGy (range 1800-6000). The following factors were associated with a higher odd of having a stroke: radiation necrosis (OR 4.51; 95% CI 1.98-10.29, P=0.0003); hypertension (OR 1.82; 95% CI 1.17-2.82, P=0.008); hyperlipidemia (OR 5.50; 95% CI 3.45-8.78, P<0.0001); and diabetes (OR 2.19; 95% CI 1.25-3.84, P=0.007). Among stroke patients, 80.6% had strokes on the same side as radiation therapy. Those who were taking bevacizumab were more likely to have an ICH (31.7% vs. 15.1%, OR 2.60, 95% CI 0.87-7.77, P=0.09) as compared to other stroke types. Conclusions: Individuals with primary brain gliomas undergoing radiation therapy who were subsequently diagnosed with a stroke had higher rates of comorbid vascular risk factors and radiation necrosis.