Glioblastoma multiforme (GBM) is the most common brain tumor in adults. The strikingly poor survival for patients with GBM (average survival 14-16 months following diagnosis) is due in part to limited early detection methods and an absence of effective therapeutic options. The study proposed would establish important evidence for the use of Health Canada approved drugs such as amantadine as a safe, effective and affordable way to monitor GBM. The method is based on the overproduction of a key enzyme in GBM cells called spermine/ spermidine n-acetyl transferase (SSAT1). The increased SSAT1 expression in GBM results in increased metabolism of the drug which is detected in the blood or urine of patients with GBM. The levels of acetyl-amantadine captured will be correlated with the tumor burden as seen on the MRIs of these patients. Thus, the study aims to determine the usefulness of amantadine as a diagnostic biomarker for GBM.