title: Advances in MRI assessment of gliomas and response to anti-VEGF therapy.
abstract: Bevacizumab is thought to normalize tumor vasculature and restore the blood-brain barrier, decreasing enhancement and peritumoral edema. Conventional measurements of tumor response rely upon dimensions of enhancing tumor. After bevacizumab treatment, glioblastomas are more prone to progress as nonenhancing tumor. The RANO (Response Assessment in Neuro-Oncology) criteria for glioma response use fluid-attenuated inversion recovery (FLAIR)/T2 hyperintensity as a surrogate for nonenhancing tumor; however, nonenhancing tumor can be difficult to differentiate from other causes of FLAIR/T2 hyperintensity (e.g., radiation-induced gliosis). Due to these difficulties, recent efforts have been directed toward identifying new biomarkers that either predict treatment response or accurately measure response of both enhancing and nonenhancing tumor shortly after treatment initiation. This will allow for earlier treatment decisions, saving patients from the adverse effects of ineffective therapies while allowing them to try alternative therapies sooner. An active area of research is the use of physiologic imaging, which can potentially detect treatment effects before changes in tumor size are evident.
authors.affiliation: Department of Radiological Sciences, David Geffen School of Medicine at UCLA, 10833 Le Conte Avenue, BL-428 CHS, Los Angeles, CA 90095-1721, USA. wpope@mednet.ucla.edu
authors.forename: Whitney B
authors.initials: WB
authors.lastname: Pope
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Young
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Ellingson
mesh_terms: D020533:Angiogenesis Inhibitors / Q000627:therapeutic use*; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D061067:Antibodies, Monoclonal, Humanized; D000068258:Bevacizumab; D014408:Biomarkers, Tumor; D005910:Glioma / Q000473:pathology* / Q000628:therapy*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D042461:Vascular Endothelial Growth Factor A / Q000276:immunology*
chemical_list: D020533:Angiogenesis Inhibitors; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D014408:Biomarkers, Tumor; D042461:Vascular Endothelial Growth Factor A; D000068258:Bevacizumab