Serum Vascular Endothelial Growth Factor and Endostatin as an adjunct to clinical decision making in managing radiation induced changes post Gamma Knife Radiosurgery in Spetzler Martin Grade 3 Arterio-venous Malformations patients: A pilot Study

Background Radiation induced changes (RIC) are the most common complications observed post GKRS and may be observed within 6-18months post procedure. It has been observed that almost one third of RICs are symptomatic and half of them are persistent. There is no way to predict which patients will develop these changes and to what extent.This was a prospective analytical pilot study with the aim of understanding the role of Serum Vascular Endothelial Growth Factor and Endostatin as a predictive factor for clinically symptomatic RIC in intracranial AVMs Spetzler Martin (SM) grade 3 being managed with primary Gamma Knife radiosurgery.Total of 15 patients were analysed. 60% of them had a history of bleed. The median volume of AVM Nidus was 4.36 cc. One third of the patients had no imaging changes suggestive of RIC at 1 year follow up and 2 of the patients had symptomatic RIC needing intervention. Before Gamma Knife, the median values of serum concentration of Endostatin and VEGF are 34.98 ng/mL and 168.37 pg/mL respectively . The serum values of VEGF at 1 month post GKRS was much less than the pre GKRS values but not found to be predictive of RIC. No correlation could be observed with the levels of serum endostatin and RIC.Some patients may develop resistant oedema and necrosis post GKRS for intracranial AVMs which may warrant medical and surgical intervention. Serum biomarkers like VEGF and Endostatin may vary in post GKRS period fpo can be used to identify at risk cases, however more studies are needed to decide on appropriate time of sampling and identify clinically relevant predictive factors.