title: Pseudoprogression, radionecrosis, inflammation or true tumor progression? challenges associated with glioblastoma response assessment in an evolving therapeutic landscape.
abstract: The wide variety of treatment options that exist for glioblastoma, including surgery, ionizing radiation, anti-neoplastic chemotherapies, anti-angiogenic therapies, and active or passive immunotherapies, all may alter aspects of vascular permeability within the tumor and/or normal parenchyma. These alterations manifest as changes in the degree of contrast enhancement or T2-weighted signal hyperintensity on standard anatomic MRI scans, posing a potential challenge for accurate radiographic response assessment for identifying anti-tumor effects. The current review highlights the challenges that remain in differentiating true disease progression from changes due to radiation therapy, including pseudoprogression and radionecrosis, as well as immune or inflammatory changes that may occur as either an undesired result of cytotoxic therapy or as a desired consequence of immunotherapies.
authors.affiliation: UCLA Brain Tumor Imaging Laboratory (BTIL), David Geffen School of Medicine, Center for Computer Vision and Imaging, University of California Los Angeles, 924 Westwood Blvd., Suite 615, Los Angeles, CA, 90024, USA. bellingson@mednet.ucla.edu.|UCLA Neuro-Oncology Program, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA. bellingson@mednet.ucla.edu.|Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA. bellingson@mednet.ucla.edu.
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Ellingson
authors.affiliation: Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Caroline
authors.initials: C
authors.lastname: Chung
authors.affiliation: Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
authors.forename: Whitney B
authors.initials: WB
authors.lastname: Pope
authors.affiliation: Department of Diagnostic Imaging, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, RI, USA.
authors.forename: Jerrold L
authors.initials: JL
authors.lastname: Boxerman
authors.affiliation: Department of Radiology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Kaufmann
mesh_terms: D001921:Brain / Q000000981:diagnostic imaging; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy*; D018450:Disease Progression; D005909:Glioblastoma / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D007249:Inflammation / Q000000981:diagnostic imaging / Q000209:etiology; D009336:Necrosis / Q000000981:diagnostic imaging / Q000209:etiology; D011832:Radiation Injuries / Q000000981:diagnostic imaging / Q000209:etiology
keywords: Glioblastoma; Imaging; Pseudoprogression; Radiation necrosis