title: Current standards and new concepts in MRI and PET response assessment of antiangiogenic therapies in high-grade glioma patients.
abstract: Despite multimodal treatment, the prognosis of high-grade gliomas is grim. As tumor growth is critically dependent on new blood vessel formation, antiangiogenic treatment approaches offer an innovative treatment strategy. Bevacizumab, a humanized monoclonal antibody, has been in the spotlight of antiangiogenic approaches for several years. Currently, MRI including contrast-enhanced T1-weighted and T2/fluid-attenuated inversion recovery (FLAIR) images is routinely used to evaluate antiangiogenic treatment response (Response Assessment in Neuro-Oncology criteria). However, by restoring the blood-brain barrier, bevacizumab may reduce T1 contrast enhancement and T2/FLAIR hyperintensity, thereby obscuring the imaging-based detection of progression. The aim of this review is to highlight the recent role of imaging biomarkers from MR and PET imaging on measurement of disease progression and treatment effectiveness in antiangiogenic therapies. Based on the reviewed studies, multimodal imaging combining standard MRI with new physiological MRI techniques and metabolic PET imaging, in particular amino acid tracers, may have the ability to detect antiangiogenic drug susceptibility or resistance prior to morphological changes. As advances occur in the development of therapies that target specific biochemical or molecular pathways and alter tumor physiology in potentially predictable ways, the validation of physiological and metabolic imaging biomarkers will become increasingly important in the near future.
authors.affiliation: Department of Neurology and Wilhelm-Sander Neuro-Oncology Unit, University Hospital and Medical School, Regensburg, Germany (M.H., P.H.); Neuroradiology, Department of Radiology, University Hospital Bonn, Bonn, Germany (E.H.); Regensburg Medical Image Computing, Ostbayerische Technische Hochschule Regensburg, Regensburg, Germany (C.P.); Department of Neurosurgery, University Hospital and Medical School, Regensburg, Germany (M.P.).
authors.forename: Markus
authors.initials: M
authors.lastname: Hutterer
authors.affiliation: Department of Neurology and Wilhelm-Sander Neuro-Oncology Unit, University Hospital and Medical School, Regensburg, Germany (M.H., P.H.); Neuroradiology, Department of Radiology, University Hospital Bonn, Bonn, Germany (E.H.); Regensburg Medical Image Computing, Ostbayerische Technische Hochschule Regensburg, Regensburg, Germany (C.P.); Department of Neurosurgery, University Hospital and Medical School, Regensburg, Germany (M.P.).
authors.forename: Elke
authors.initials: E
authors.lastname: Hattingen
authors.affiliation: Department of Neurology and Wilhelm-Sander Neuro-Oncology Unit, University Hospital and Medical School, Regensburg, Germany (M.H., P.H.); Neuroradiology, Department of Radiology, University Hospital Bonn, Bonn, Germany (E.H.); Regensburg Medical Image Computing, Ostbayerische Technische Hochschule Regensburg, Regensburg, Germany (C.P.); Department of Neurosurgery, University Hospital and Medical School, Regensburg, Germany (M.P.).
authors.forename: Christoph
authors.initials: C
authors.lastname: Palm
authors.affiliation: Department of Neurology and Wilhelm-Sander Neuro-Oncology Unit, University Hospital and Medical School, Regensburg, Germany (M.H., P.H.); Neuroradiology, Department of Radiology, University Hospital Bonn, Bonn, Germany (E.H.); Regensburg Medical Image Computing, Ostbayerische Technische Hochschule Regensburg, Regensburg, Germany (C.P.); Department of Neurosurgery, University Hospital and Medical School, Regensburg, Germany (M.P.).
authors.forename: Martin Andreas
authors.initials: MA
authors.lastname: Proescholdt
authors.affiliation: Department of Neurology and Wilhelm-Sander Neuro-Oncology Unit, University Hospital and Medical School, Regensburg, Germany (M.H., P.H.); Neuroradiology, Department of Radiology, University Hospital Bonn, Bonn, Germany (E.H.); Regensburg Medical Image Computing, Ostbayerische Technische Hochschule Regensburg, Regensburg, Germany (C.P.); Department of Neurosurgery, University Hospital and Medical School, Regensburg, Germany (M.P.).
authors.forename: Peter
authors.initials: P
authors.lastname: Hau
mesh_terms: D020533:Angiogenesis Inhibitors / Q000627:therapeutic use*; D015415:Biomarkers; D001932:Brain Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology*; D003287:Contrast Media; D018450:Disease Progression; D005910:Glioma / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000639:trends; D009389:Neovascularization, Pathologic / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D049268:Positron-Emission Tomography / Q000379:methods* / Q000639:trends
chemical_list: D020533:Angiogenesis Inhibitors; D015415:Biomarkers; D003287:Contrast Media
keywords: MRI; PET; antiangiogenic treatment; high-grade glioma; multimodal response assessment