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

BACKGROUND: 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.

METHODS: 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 Ktrans , plasma volume (Vp ) and reflux rate constant between fractional volume of the extravascular space and blood plasma (Kep ). Nonparametric Mann-Whitney test and Kaplan-Meier survival analyses were conducted and a P value < 0.05 was considered statistically significant.

RESULTS: 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 Ktrans (0.31/minute vs. 0.53/minute; P = 0.02), and Kep (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-Kep compared with patients with low-VWF:Ag and low-Kep (37.5% vs. 68%; P = 0.05).

CONCLUSIONS: These findings, in a small group of patients, suggest a role for VWF:Ag, similar to Ktrans , and Kep as a prognostic indicator of postoperative survival of patients with GBM.