title: Quantification of edema reduction using differential quantitative T2 (DQT2) relaxometry mapping in recurrent glioblastoma treated with bevacizumab.
abstract: The purpose of the current study was to quantify the reduction in T2 signal abnormality accompanying administration of the anti-angiogenic drug bevacizumab in recurrent glioblastoma (GBM) patients using a voxel-wise differential quantitative T2 (DQT2) mapping technique. Twenty-six patients with recurrent GBM treated with bevacizumab were scanned before and 4-6 weeks after treatment on a 1.5T clinical MR scanner. Quantitative T2 maps were created from proton density and T2-weighted images acquired using a standard multi-echo fast-spin echo sequence. T2 maps after treatment were co-registered with T2 maps prior to treatment in the same patient, and then voxel-wise subtraction was performed to create DQT2 maps for each patient. Results suggest DQT2 maps allow visualization and quantification of voxel-wise T2 changes resulting from anti-VEGF therapy. Results demonstrated a significant decrease in T2 within pre-treatment T2 abnormal regions (mean reduction = 49.4 ms at 1.5T) following anti-VEGF treatment (Wilcoxon signed rank test, P < 0.0001). An elevated residual, post-treatment, median T2 was predictive of both progression-free (Log-rank, P = 0.0074) and overall survival (Log-rank, P = 0.0393).
authors.affiliation: Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, 924 Westwood Blvd., Suite 650, Los Angeles, CA 90095, USA. bellingson@mednet.ucla.edu
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Ellingson
authors.forename: Timothy F
authors.initials: TF
authors.lastname: Cloughesy
authors.forename: Albert
authors.initials: A
authors.lastname: Lai
authors.forename: Phioanh L
authors.initials: PL
authors.lastname: Nghiemphu
authors.forename: Shadi
authors.initials: S
authors.lastname: Lalezari
authors.forename: Taryar
authors.initials: T
authors.lastname: Zaw
authors.forename: Kourosh
authors.initials: K
authors.lastname: Motevalibashinaeini
authors.forename: Paul S
authors.initials: PS
authors.lastname: Mischel
authors.forename: Whitney B
authors.initials: WB
authors.lastname: Pope
mesh_terms: D020533:Angiogenesis Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized / Q000009:adverse effects / Q000627:therapeutic use*; D000068258:Bevacizumab; D001929:Brain Edema / Q000150:complications / Q000175:diagnosis*; D001931:Brain Mapping; D001932:Brain Neoplasms / Q000150:complications* / Q000188:drug therapy*; D003952:Diagnostic Imaging; D018450:Disease Progression; D018572:Disease-Free Survival; D005909:Glioblastoma / Q000150:complications* / Q000188:drug therapy*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D053208:Kaplan-Meier Estimate; D008279:Magnetic Resonance Imaging; D012189:Retrospective Studies; D016019:Survival Analysis; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors
chemical_list: D020533:Angiogenesis Inhibitors; D061067:Antibodies, Monoclonal, Humanized; D042461:Vascular Endothelial Growth Factor A; D000068258:Bevacizumab