title: Serial diffusion tensor imaging for early detection of radiation-induced injuries to normal-appearing white matter in high-grade glioma patients.
abstract: OBJECTIVE
  To study the potential of diffusion tensor imaging (DTI) to serve as a biomarker for radiation-induced brain injury during chemo-radiotherapy (RT) treatment.
  
  
  METHODS
  Serial DTI data were collected from 18 high-grade glioma (HGG) patients undergoing RT and 7 healthy controls. Changes across time in mean, standard deviation (SD), skewness, and kurtosis of fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (λa ), and transversal diffusivity (λt ) within the normal-appearing white matter (NAWM) were modeled using a linear mixed-effects model to assess dose dependent changes of five dose bins (0-60 Gy), and global changes compared with a control group.
  
  
  RESULTS
  Mean MD, λa and λt were all significantly increasing in >41 Gy dose regions (0.14%, 0.10%, and 0.18% per week) compared with <12 Gy regions. SD λt had significant dose dependent time evolution of 0.019*dose per week. Mean and SD MD, λa and λt in the global NAWM of the patient group significantly increased (mean; 0.06%, 0.03%, 0.09%, and SD; 0.57%, 0.34%, 0.51 per week) compared with the control group. The changes were significant at week 6 of, or immediately after RT.
  
  
  CONCLUSIONS
  DTI is not sensitive to acute global NAWM changes during the treatment of HGG, but sensitive to early posttreatment changes.
authors.affiliation: Norwegian University of Science and Technology, Trondheim, Norway; The Intervention Centre, Oslo University Hospital Rikshospitalet, Oslo, Norway.
authors.forename: Tuva R
authors.initials: TR
authors.lastname: Hope
authors.forename: Jonas
authors.initials: J
authors.lastname: Vardal
authors.forename: Atle
authors.initials: A
authors.lastname: Bjørnerud
authors.forename: Christopher
authors.initials: C
authors.lastname: Larsson
authors.forename: Marius R
authors.initials: MR
authors.lastname: Arnesen
authors.forename: Raimo A
authors.initials: RA
authors.lastname: Salo
authors.forename: Inge R
authors.initials: IR
authors.lastname: Groote
mesh_terms: D000328:Adult; D000368:Aged; D016880:Anisotropy; D001932:Brain Neoplasms / Q000532:radiotherapy* / Q000601:surgery; D016022:Case-Control Studies; D003131:Combined Modality Therapy; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D005910:Glioma / Q000532:radiotherapy* / Q000601:surgery; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011832:Radiation Injuries / Q000175:diagnosis*; D066127:White Matter / Q000528:radiation effects*
keywords: diffusion tensor imaging; glioblastoma tumors; longitudinal analysis; radiation injury; white matter