title: Low incidence of pseudoprogression by imaging in newly diagnosed glioblastoma patients treated with cediranib in combination with chemoradiation.
abstract: BACKGROUND
  Chemoradiation (CRT) can significantly modify the radiographic appearance of malignant gliomas, especially within the immediate post-CRT period. Pseudoprogression (PsP) is an increasingly recognized phenomenon in this setting, and is thought to be secondary to increased permeability as a byproduct of the complex process of radiation-induced tissue injury, possibly enhanced by temozolomide. We sought to determine whether the addition of a vascular endothelial growth factor (VEGF) signaling inhibitor (cediranib) to conventional CRT had an impact on the frequency of PsP, by comparing two groups of patients with newly diagnosed glioblastoma before, during, and after CRT.
  
  
  METHODS
  All patients underwent serial magnetic resonance imaging as part of institutional review board-approved clinical studies. Eleven patients in the control group received only chemoradiation, whereas 29 patients in the study group received chemoradiation and cediranib until disease progression or toxicity. Response assessment was defined according to Response Assessment in Neuro-Oncology criteria, and patients with enlarging lesions were classified into true tumor progressions (TTP) or PsP, based on serial radiographic follow-up.
  
  
  RESULTS
  Two patients in the study group (7%) showed signs of apparent early tumor progression, and both were subsequently classified as TTP. Six patients in the control group (54%) showed signs of apparent early tumor progression, and three were subsequently classified as TTP and three as PsP. The frequency of PsP was significantly higher in the control group.
  
  
  CONCLUSIONS
  Administration of a VEGF inhibitor during and after CRT modifies the expression of PsP by imaging.
authors: Departments of Radiology, Neurology, and Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts, USA; Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts, USA; The Intervention Centre, Oslo University Hospital, Oslo, Norway; Center for Neuro-Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.
authors: Marco C
authors: MC
authors: Pinho
authors: Pavlina
authors: P
authors: Polaskova
authors: Jayashree
authors: J
authors: Kalpathy-Cramer
authors: Dominique
authors: D
authors: Jennings
authors: Kyrre E
authors: KE
authors: Emblem
authors: Rakesh K
authors: RK
authors: Jain
authors: Bruce R
authors: BR
authors: Rosen
authors: Patrick Y
authors: PY
authors: Wen
authors: A Gregory
authors: AG
authors: Sorensen
authors: Tracy T
authors: TT
authors: Batchelor
authors: Elizabeth R
authors: ER
authors: Gerstner
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy*; D059248:Chemoradiotherapy; D003606:Dacarbazine / Q000008:administration & dosage / Q000031:analogs & derivatives; D018450:Disease Progression; D005260:Female; D005909:Glioblastoma / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D015994:Incidence; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011799:Quinazolines / Q000008:administration & dosage; D000077204:Temozolomide; D055815:Young Adult; D007211:Indoles
chemical_list: D003606:Dacarbazine; D011799:Quinazolines; D000077204:Temozolomide; C500926:cediranib; D007211:Indoles
keywords: Cediranib; Glioblastoma; Pseudoprogression; Vascular endothelial growth factor