To describe the characteristics and risk factors of patients who suffered strokes after radiation therapy for primary brain tumors.

Strokes can complicate the treatment of individuals with primary brain tumors due to several possible mechanisms including chemotherapy and radiation-induced toxicity as well as disease-specific etiologies.  Little is known about the prevalence and risk factors of stroke in this population.

This is a retrospective cohort from a single tertiary academic brain tumor center of patients with primary brain tumors who also received radiation therapy.  We report on the prevalence and types of strokes following brain tumor diagnosis and compare the risk factors among those with or without stroke.

We identified 443 patients with primary brain tumors who had received radiation therapy. 63 patients (14.2%), with 52.4% male and 47.6% female, mean age 57.46 (SD 12.46), were found to have suffered a stroke, 40 being ischemic (63.5%) and 23 hemorrhagic (36.5%), during their treatment course. Patients who had a stroke were more likely to have hyperlipidemia (66.7% vs. 30.6%, OR 4.91, 95% CI 2.78-8.67, P<0.0001), diabetes mellitus (17.5% vs. 8.4%, OR 2.68, 9%% CI 2.67-5.67, P=0.01), hypertension (57.6% vs. 49.6%, OR 1.51, 95% CI 0.88-2.59, P=0.13), and obstructive sleep apnea (9.5% vs. 4.7%, OR 2.25, 95% CI 0.85-5.94, P=0.10). In the patients with stroke, 65.1% were on bevacizumab at the time of the stroke. Of the 62 patients with stroke in known locations, 82% had strokes on the same side as radiation with 53% having strokes in the same location of radiation therapy.

Patients with primary brain tumors undergoing radiation therapy who were diagnosed with stroke had higher rates of comorbid vascular risk factors, with statistically significantly higher odds of hyperlipidemia and diabetes and more often had strokes on the same side and location as their radiation therapy.