Glioblastoma (GBM) is the most common and aggressive primary tumour. Its prognosis is very poor, with survival ranging from 12-15 months. Due to the chemoresistance and highly infiltrative growth of GBM, current treatments can only slow the development of the disease. The main limit to the effectiveness of chemotherapies in the brain is their restricted access due to the presence of the blood brain barrier (BBB), which limits the passage of most drugs. Recently, focused ultrasound (FUS) in combination with microbubbles, has attracted attention as a non-invasive means of temporarily opening the blood-brain barrier (1). X-ray fluorescence (XRF) imaging is a powerful imaging technique for quantification of trace elements in biological samples. In this study, we propose use XRF to quantify platinum concentrations in the brains of F98 glioma-bearing rats after FUS-enhanced chemotherapy of carboplatin, in comparison to simple carboplatin intravenous injections.