title: Histogram analysis of apparent diffusion coefficient within enhancing and nonenhancing tumor volumes in recurrent glioblastoma patients treated with bevacizumab.
abstract: While patients with recurrent glioblastoma receiving anti-angiogenic therapy demonstrate significant response rates, the benefit on patient survival is less clear. We assessed whether histogram analysis of diffusion weighted MRI can stratify for progression-free and overall survival. Baseline and 3-6 week post-treatment MRI exams of 91 patients with recurrent glioblastoma treated with bevacizumab were retrospectively evaluated. Histograms of apparent diffusion coefficient (ADC) within the volume of contrast enhancing and nonenhancing T2/FLAIR lesions were analyzed using curve-fit analysis. Overall survival (OS) and progression-free survival (PFS) were assessed using ADC parameters in a Cox proportional hazards model adjusted for clinical variables. Baseline ADC(L)/ADC(M) within nonenhancing T2/FLAIR volume (> or ≤0.64) can stratify OS (HR = 2.24, p = 0.002) and PFS (HR = 1.90, p = 0.005). %ADC(H) within enhancing T1+C volume (> or ≤25 %) can also stratify OS (HR = 0.59, p = 0.034) and PFS (HR = 0.56, p = 0.01). Stratification of patient survival can be improved by merging these two ADC parameters into a single combined ADC factor (HR = 0.17, p < 0.0001). The median OS ratio of patient groups stratified by this combined factor was 2.03, larger than median OS ratio when stratifying by either %ADC(H) within T1+C volume alone (1.3) or ADC(L)/ADC(M) within T2/FLAIR alone (1.86). ADC histogram analysis within both enhancing and nonenhancing components of tumor can be used to stratify for PFS and OS in patients with recurrent glioblastoma.
authors.affiliation: Harvard Medical School, Boston, MA, USA.
authors.forename: Rifaquat
authors.initials: R
authors.lastname: Rahman
authors.forename: Alhafidz
authors.initials: A
authors.lastname: Hamdan
authors.forename: Rebecca
authors.initials: R
authors.lastname: Zweifler
authors.forename: Han
authors.initials: H
authors.lastname: Jiang
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Norden
authors.forename: David A
authors.initials: DA
authors.lastname: Reardon
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Mukundan
authors.forename: Patrick Y
authors.initials: PY
authors.lastname: Wen
authors.forename: Raymond Y
authors.initials: RY
authors.lastname: Huang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; 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; D018450:Disease Progression; D005260:Female; D005909:Glioblastoma / Q000188:drug therapy / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy / Q000473:pathology*; D011379:Prognosis; D012189:Retrospective Studies; D047368:Tumor Burden; D055815:Young Adult
chemical_list: D020533:Angiogenesis Inhibitors; D061067:Antibodies, Monoclonal, Humanized; D000068258:Bevacizumab