Abstract #4265

Prognostic Imaging Markers in Patients with GBM: Comparison between Functional Versus Mean KPS Analysis

Andrea Kassner¹, Igor Sitartchouk¹, Fang Liu², Jeremy Hoisak³, Adam Gladwish³, Normand Laperriere³, Cynthia Menard³

¹Medical Imaging, University of Toronto, Toronto, Ontario, Canada; ²Diagnostic Imaging, Hospital for Sick Children, Toronto; ³Radiation Oncology, University of Toronto, Toronto

Glioblastoma multiforme (GBM) is the most common primary brain tumor and has a very poor prognosis. Treatment assessment is difficult as early imaging changes cannot be easily differentiated from tumor progression (i.e. pseudo early progression). We used DCE-MRI to obtain coefficients of permeability estimates (KPS) from 25 GBM patients at three different timepoints (baseline, during radiotherapy, post radiotherapy) and found that mean KPS of pseudo early progressors was signifcantly greater than in early progressors (EPs)during radiotherapy and shows a potential for discrimination EPs from pseudo EPs.