Differentiating Glioblastomas from Solitary Brain Metastases Using Arterial Spin Labeling Perfusion- and Diffusion Tensor Imaging-Derived Metrics.

Abstract

We sought to differentiate glioblastomas from solitary brain metastasis using arterial spin labeling perfusion (ASL)- and diffusion tensor imaging (DTI)-derived metrics. A prospective study was done on 36 patients with provisional diagnosis of glioblastomas versus brain metastasis who underwent ASL and DTI of the brain. The tumor blood flow (TBF) and DTI metrics (fractional anisotropy [FA] and mean diffusivity [MD]) of the enhancing tumoral and peritumoral parts were measured. There was a significant difference of TBF (P = 0.001) and MD (P = 0.001) of the tumoral and peritumoral parts of glioblastoma and metastasis (P = 0.001). There was a significant difference of FA of peritumoral part (P = 0.001) and insignificant difference of tumoral part (P = 0.06) between glioblastomas and metastasis. The cutoff of TBF of tumoral and peritumoral parts used for differentiation were 29.7 and 17.8 (mL/100 g/minute) revealed an area under the curve (AUC) of 0.943 and 0.937 with accuracy of 91.7% and 88.9%. The cutoff of MD of tumoral and peritumoral parts were 1.27 and 1.33 (10^-3 mm²/second) revealed AUC of 0.840 and 0.987 and accuracy of 83.3% and 91.7%, respectively. Combined TBF, MD, and FA of the peritumoral part revealed AUC of 0.984 and accuracy of 91.7%. A combination of ASL- and DTI-derived metrics of the peritumoral part can be used for differentiation of glioblastomas from solitary brain metastasis.