title: Nonlinear registration of diffusion-weighted images improves clinical sensitivity of functional diffusion maps in recurrent glioblastoma treated with bevacizumab.
abstract: Diffusion-weighted imaging estimates of apparent diffusion coefficient (ADC) have shown sensitivity to brain tumor cellularity as well as response to therapy. Functional diffusion maps (fDMs) exploit these principles by examining voxelwise changes in ADC within the same patient over time. Currently, the fDM technique involves linear image registration of ADC maps from subsequent follow-up times to pretreatment ADC maps; however, misregistration of ADC maps due to geometric distortions as well as mass effect from growing tumor can confound fDM measurements. In this study, we compare the use of a nonlinear registration scheme to the current linear fDM technique in 70 patients with recurrent glioblastoma multiforme treated with bevacizumab. Results suggest that nonlinear registration of pretreatment ADC maps to post-treatment ADC maps improves the clinical predictability, sensitivity, and specificity of fDMs for both progression-free and overall survival.
authors.affiliation: Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, 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: Whitney B
authors.initials: WB
authors.lastname: Pope
mesh_terms: D000465:Algorithms; D020533:Angiogenesis Inhibitors / Q000627:therapeutic use; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D000068258:Bevacizumab; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005909:Glioblastoma / Q000188:drug therapy* / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D009364:Neoplasm Recurrence, Local / Q000473:pathology / Q000517:prevention & control*; D017711:Nonlinear Dynamics; D010363:Pattern Recognition, Automated / Q000379:methods; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D016896:Treatment Outcome
chemical_list: D020533:Angiogenesis Inhibitors; D061067:Antibodies, Monoclonal, Humanized; D000068258:Bevacizumab