Adverse Radiation Effects

This prospective observational study will investigate the relationship between the gut microbiome and adverse effects following stereotactic radiosurgery (SRS). Patients undergoing SRS as part of their standard clinical care will provide blood and stool samples before treatment and during follow-up. Samples will be analyzed to characterize fecal and blood metabolomic profiles and changes in the gut microbiome over time. The study has two primary objectives: to determine how stereotactic radiosurgery affects the gut microbiome and associated metabolomic profiles, and to evaluate whether microbiome- and metabolite-associated features are related to the development of adverse effects following SRS. Clinical data and standard-of-care neuroimaging will be collected longitudinally to identify outcomes including radiation necrosis and other adverse radiation effects. Biological profiles from patients who develop these outcomes will be compared with those from patients who do not, as well as within individual patients over time. The study aims to identify microbiome and metabolic signatures associated with susceptibility to adverse effects of stereotactic radiosurgery, with the long-term goal of improving risk stratification and informing future approaches to monitoring and treatment.