LAUSR

OBJECTIVE Gamma knife surgery is a complementary procedure to open microsurgery for several indications. However, post-treatment symptomatic complaints are common and often result in short-term follow up imaging. Here we evaluate the efficacy of repeat brain imaging within 30 days of a gamma knife procedure by analyzing the frequency with which that imaging reveals addressable pathology. METHODS All patients who underwent gamma knife treatments at our institution between January 2013 and August 2019 were retrospectively analyzed and any patient who received imaging of the brain within 30 days for a symptomatic complaint was evaluated. RESULTS Of the 956 gamma knife cases performed, there were 78 (8.2%) scans performed within a 30-day time frame for symptomatic complaints. Of these, the most common complaint was headache (25%). Most images demonstrated no changes when compared to the treatment scan (68%) and there were no hemorrhages and only one stroke (<1%). Univariate analysis revealed that sex (p =0.046), treatment volume (p < 0.001), and treatments for metastasis (p < 0.001) or glioma (p < 0.001) were associated with symptomatic complaints leading to imaging, but no factors were associated with higher rates of abnormal imaging. CONCLUSIONS Gamma knife therapy remains a safe treatment for multiple indications, but it is not risk free and acute symptomatic complaints are common. However, our data suggests that the need for re-imaging within 30 days for symptomatic complaints is likely overestimated as obtained imaging does not usually show any change and the rate of significant complication is exceedingly low.