Tracking normalization of brain tumor vasculature by magnetic imaging and proangiogenic biomarkers

Abstract

Clinical assessment of the response to antiangiogenic therapy has been cumbersome. A study in this issue of Cancer Cell demonstrates that a combination of magnetic resonance imaging (MRI) for quantification of normalized vessels with measurements of circulating levels of proangiogenic factors, including FGF2, SDF1, and viable circulating endothelial cells, provides an effective means to evaluate the response of recurrent glioblastoma to a prototypical pan-VEGF receptor tyrosine kinase inhibitor, AZD2171.

Figure 1. Assessment of Response to Antiangiogenic Therapy with AZD2171 by Utilizing MRI and Biomarkers

ZD2171 targets immature vessels, while favoring the emergence of normalized pericyte coated blood vessels. Recurrence of the tumor is associated with generation of dilated, large, and leaky blood vessels as well as plasma elevation of proangiogenic factors, including FGF2, SDF1, and CECs. Normalization of the blood vessels is associated with a decrease in post-contrast T1-weighted MRI signal (T1), T2-weighted (flair, T2), permeability (K^trans), and recovery of white matter integrity as detected by white matter tractography (WM). The MRI photographs were adapted from Batchelor et al. (2007).