Using DWI-MRI parameters from multi-B values acquisition and a histogram approach for assessment of early therapeutic response in glioblastoma

Early evaluation of therapeutic response of GBM on imaging is limited by poor biological specificity of clinical MRI. Clinical DWI-MRI models assume diffusion is mono-exponential when derived from only two B-values, although it has been proven diffusion is multiexponential. Purpose To assess the utility of quantitative diffusion MRI derived from multi B-value acquisitions in the assessment of treatment response. Methods 13 patients were enrolled into our multicentre study. Imaging was performed pre-RT and mid-RT using a multi B-value acquisition. Histograms within ROIs defined by abnormal FLAIR signal. Changes in histogram percentile profiles were evaluated across the two timepoints and compared with RANO assessment. Results Following treatment, 5 patients had PD, 4 SD and 4 CR. Patients with PD showed a histogram shift to the left across all models, in keeping with increased cellularity. Parameters …