Use of quantitative diffusion-weighted MR imaging (DWI) in differentiating between glioblastoma and primary central nervous system lymphoma in real-time exam interpretation

Given the significant different treatment strategy of glioblastoma compared to lymphoma, early non-invasive differentiation of these two malignant brain tumours is essential for treatment planning.Our study investigates the feasibility of differentiation of glioblastoma from lymphoma by measuring the apparent diffusion coefficient (ADC) values of the tumour using a very easy method on radiology PACS workstation.Forty-two (42) patients with pathology proven glioblastoma and 30 patients with pathology proven primary CNS lymphoma were retrospectively reviewed.Two different readers placed the regions of interest in the nonhaemorrhagic darkest solid area of the tumour to measure the ADC values.The median of the "Mean ADC Values" (averaged between two interpreters) in the primary CNS lymphoma group was significantly lower than the median of "Mean ADC Values" in the glioblastoma group for both readers (p < 0.0001) [582 (511,687) × 10 -6 mm 2 /s for the lymphoma group and 789 (734,896) × 10 -6 mm 2 /s for the GBM group].Our study offers a novel, effective and easy approach for differentiation of the glioblastoma from lymphoma.