title: Diffusion tensor imaging predicts cognitive function change following partial brain radiotherapy for low-grade and benign tumors.
abstract: Radiation injury to parahippocampal cingulum white matter is associated with cognitive decline. Diffusion tensor imaging (DTI) detects micropathologic changes in white matter. Increased radial diffusion (RD) and decreased axial diffusion (AD) correspond to demyelination and axonal degeneration/gliosis respectively. We aimed to develop a predictive model for radiation-induced cognitive changes based upon DTI changes.
  
  
  
  Twenty-seven adults with benign or low-grade tumors received partial brain radiation therapy (RT) to a median dose of 54Gy. Patients underwent DTI before RT, during RT, and at the end of RT. Cognitive testing was performed before RT, and 6 and 18months after RT. Parahippocampal cingulum white matter was contoured to obtain mean values of AD and RD.
  
  
  
  By univariate analysis, decreasing AD and increasing RD during RT predicted declines in verbal memory and verbal fluency. By multivariate analysis, baseline neurocognitive score was the only clinical variable predicting verbal memory change; no clinical variables predicted verbal fluency change. In a multivariate model, increased RD at the end of RT significantly predicted decline in verbal fluency 18months after RT.
  
  
  
  Imaging biomarkers of white matter injury contributed to predictive models of cognitive function change after RT.
authors.affiliation: Department of Radiation Oncology, University of Michigan, Ann Arbor, USA; Department of Radiation Oncology, University of California San Francisco, USA. Electronic address: christopher.chapman@ucsf.edu.
authors.forename: Christopher H
authors.initials: CH
authors.lastname: Chapman
authors.affiliation: Department of Radiation Oncology, University of Michigan, Ann Arbor, USA.
authors.forename: Tong
authors.initials: T
authors.lastname: Zhu
authors.affiliation: Department of Radiation Oncology, University of Michigan, Ann Arbor, USA; Radiology and Research Administration Departments, Henry Ford Hospital, Detroit, USA.
authors.forename: Mohamad
authors.initials: M
authors.lastname: Nazem-Zadeh
authors.affiliation: Department of Biostatistics, University of Michigan, Ann Arbor, USA.
authors.forename: Yebin
authors.initials: Y
authors.lastname: Tao
authors.affiliation: Department of Psychiatry, University of Michigan, Ann Arbor, USA; VA Ann Arbor Healthcare System, Ann Arbor, USA.
authors.forename: Henry A
authors.initials: HA
authors.lastname: Buchtel
authors.affiliation: Department of Radiation Oncology, University of Michigan, Ann Arbor, USA; Department of Radiation Oncology, Washington University, St. Louis, USA.
authors.forename: Christina I
authors.initials: CI
authors.lastname: Tsien
authors.affiliation: Department of Radiation Oncology, University of Michigan, Ann Arbor, USA.
authors.forename: Theodore S
authors.initials: TS
authors.lastname: Lawrence
authors.affiliation: Department of Radiation Oncology, University of Michigan, Ann Arbor, USA; Department of Biomedical Engineering, University of Michigan, Ann Arbor, USA; Department of Radiology, University of Michigan, Ann Arbor, USA.
authors.forename: Yue
authors.initials: Y
authors.lastname: Cao
mesh_terms: D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D003071:Cognition / Q000528:radiation effects; D003072:Cognition Disorders / Q000000981:diagnostic imaging* / Q000209:etiology; D056324:Diffusion Tensor Imaging / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D060787:Neoplasm Grading; D009483:Neuropsychological Tests; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011832:Radiation Injuries / Q000000981:diagnostic imaging* / Q000209:etiology; D011878:Radiotherapy / Q000009:adverse effects; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D066127:White Matter / Q000000981:diagnostic imaging / Q000473:pathology / Q000528:radiation effects
keywords: Cognitive function; Glioma; Late effects; Magnetic resonance imaging