Low-grade and anaplastic oligodendrogliomas: differences in tumour microvascular permeability evaluated with dynamic contrast-enhanced magnetic resonance imaging.

This study was designed to quantitatively assess the microvascular permeability of oligodendroglioma using the volume transfer constant (K(trans)) and the volume of the extravascular extracellular space per unit volume of tissue (V(e)) with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). We aimed to evaluate the effectiveness of K(trans) and V(e) in distinguishing between low-grade and anaplastic oligodendroglioma. The maximal values of K(trans) and V(e) for 65 patients with oligodendroglioma (27 grade II, 38 grade III) were obtained. Differences in K(trans) and V(e) between the two groups were analysed using the Mann-Whitney rank-sum test. Receiver operating characteristic (ROC) curve analyses were performed to determine the cut-off values for the K(trans) and Ve that could differentiate between low-grade and anaplastic oligodendrogliomas. Values for K(trans) and Ve in low-grade oligodendrogliomas were significantly lower than those in anaplastic oligodendrogliomas (p < 0.001 and p < 0.001, respectively). ROC curve analysis showed that cut-off values of the K(trans) (0.037 min(-1)) and Ve (0.079) could be used to distinguish between low-grade and anaplastic oligodendrogliomas in a statistically significant manner. Our results suggest that DCE-MRI can distinguish the differences in microvascular permeability between low-grade and anaplastic oligodendrogliomas.