title: Evaluation of treatment-induced cerebral white matter injury by using diffusion-tensor MR imaging: initial experience.
abstract: OBJECTIVE
  Treatment with chemotherapy and radiation therapy for brain tumors can cause white matter (WM) injury. Conventional MR imaging, however, cannot always depict treatment-induced transient WM abnormalities. We investigated the ability of diffusion-tensor (DT) MR imaging and proton MR spectroscopy to detect the treatment-induced transient changes within normal-appearing WM.
  
  
  METHODS
  DT MR imaging and proton MR spectroscopy were performed in 8 patients treated with a combination of surgery, chemotherapy, and radiation therapy for brain tumors (17 examinations) and 11 age-matched controls. Apparent diffusion coefficient (ADC) value, fractional anisotropy (FA) value, and N-acetylaspartate (NAA)/creatine (Cr) ratio were obtained from 27 hemispheres with normal-appearing WM in the patients. We divided the datasets of isotropic ADC, FA, and NAA/Cr, on the basis of the time period after completion of radiation therapy, into 4 groups: group 1 (0-2 months; n = 10), group 2 (3-5 months; n = 5), group 3 (6-9 months; n = 7), and group 4 (10-12 months; n = 5). We compared averages of mean isotropic ADC, mean FA, and NAA/Cr of each patient group with those of the control group by using a t test.
  
  
  RESULTS
  In the group 2, averages of mean FA and NAA/Cr decreased and average of mean isotopic ADC increased in comparison with those of the control group (P = .004, .04, and .0085, respectively). There were no significant differences in the averages between the control group and patient groups 1, 3, and 4.
  
  
  CONCLUSIONS
  DT MR imaging and proton MR spectroscopy can provide quantitative indices that may reflect treatment-induced transient derangement of normal-appearing WM.
authors.affiliation: Departments of Radiology, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Sawako
authors.initials: S
authors.lastname: Kitahara
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nakasu
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Murata
authors.forename: Keizen
authors.initials: K
authors.lastname: Sho
authors.forename: Ryuta
authors.initials: R
authors.lastname: Ito
mesh_terms: D000328:Adult; D000368:Aged; D016880:Anisotropy; D000970:Antineoplastic Agents / Q000009:adverse effects*; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000032:analysis; D001921:Brain / Q000187:drug effects / Q000473:pathology* / Q000528:radiation effects; D001923:Brain Chemistry; D001932:Brain Neoplasms / Q000628:therapy*; D003401:Creatine / Q000032:analysis; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D011832:Radiation Injuries / Q000175:diagnosis*
chemical_list: D000970:Antineoplastic Agents; D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine