Correlation of Preoperative Von Willebrand Factor with Magnetic Resonance Imaging Perfusion and Permeability Parameters as Predictors of Prognosis in Glioblastoma.

Abstract

Angiogenesis has been shown to be strictly related to tumor malignancy. Glioblastoma (GBM) is highly vascularized and von Willebrand Factor (VWF) plays a potent proangiogenic role. Dynamic contrast-enhanced and dynamic susceptibility contrast magnetic resonance imaging (MRI) represent a widely accepted method to assess GBM microvasculature. Our aim was to investigate the correlation between plasma VWF:Ag, permeability, and perfusion MRI parameters and examine their potential in predicting GBM patient prognosis. We retrospectively analyzed preoperative dynamic contrast-enhanced, dynamic susceptibility contrast MRI, and VWF:Ag level of 26 patients with GBM. We assessed the maximum values of relative cerebral blood flow and volume, volume transfer constant K^trans, plasma volume (V_p) and reflux rate constant between fractional volume of the extravascular space and blood plasma (K_ep). Nonparametric Mann-Whitney test and Kaplan-Meier survival analyses were conducted and a P value < 0.05 was considered statistically significant. The median VWF:Ag value was 248 IU/dL and the median follow-up duration was about 13 months. We divided patients according to low-VWF:Ag and high-VWF:Ag and we found significant differences in the median follow-up duration (19 months vs. 10 months; P = 0.04) and in K^trans (0.31/minute vs. 0.53/minute; P = 0.02), and K_ep (1.79/minute vs. 3.89/minute; P = 0.005) values. The cumulative 1-year survival was significantly shorter in patients with high-VWF:Ag and high-K_ep compared with patients with low-VWF:Ag and low-K_ep (37.5% vs. 68%; P = 0.05). These findings, in a small group of patients, suggest a role for VWF:Ag, similar to K^trans, and K_ep as a prognostic indicator of postoperative survival of patients with GBM.