ACTR-42. THE USE OF ADVANCED DIFFUSION MRI PARAMETERS IN THE ASSESSMENT OF TREATMENT RESPONSE IN GLIOBLASTOMA USING MULTI-B VALUE ACQUISITION AND A HISTOGRAM-BASED APPROACH

PURPOSE: Imaging biomarkers to assess early treatment response in gliomas are important for guiding optimal clinical decision-making for individual patients, and as platforms for multi-institutional clinical trials of novel therapies. Current Response Assessment in Neuro-Oncology (RANO) criteria, rely on subjective, semi quantitative measurements with limited sensitivity and specificity in the early treatment phase. Previous diffusion imaging studies have indicated early sensitivity to treatment response, however optimum acquisition and analysis approaches have yet to be established. The purpose of this study is to assess the utility of advanced quantitative diffusion MRI derived from multi B-value acquisitions in the assessment of treatment response, using a spatially independent approach. METHODS We used least-square fitting to model six diffusion parameters from mono-, bi-, and stretch-exponential models, and …