title: MRI changes due to early-delayed conformal radiotherapy and postsurgical effects in patients with brain tumors.
abstract: OBJECTIVE
  Discernment of radiotherapy (XRT) effects vs. tumor activity is difficult in brain tumor patients during the months after XRT when white matter hyperintensities sometimes emerge. We examined brain scans in XRT-treated vs. untreated patients for early-delayed post-XRT effects.
  
  
  METHODS
  Brain regions susceptible to XRT injury were examined on magnetic resonance imaging (MRI) for T2-weighted hyperintensities and atrophy in 37 adults with low-grade primary brain tumors (13 nonirradiated and 24 irradiated). Cases evidencing recurrence/growth over the study period were censored. Interactions with age, mood, fatigue, medications, tumor type and grade, extent of resection, and laterality of MRI changes were examined.
  
  
  RESULTS
  Hyperintensity and atrophy ratings over time for the treated and untreated groups were not significantly different. White matter atrophy increased unrelated to XRT. In all patients combined, white matter atrophy and hyperintensities were greater at all time points and more lateralized in surgically treated patients.
  
  
  CONCLUSIONS
  Radiotherapy status was not related to changes in MRI ratings during the weeks/months after XRT. Findings contradict assumptions about radiographically evidenced early-delayed XRT effects. Increases in T2-weighted hyperintensities during the 1-6-month period post-conformal radiotherapy for low-grade tumors are likely not related to early-delayed XRT effects.
authors.affiliation: Department of Neurology, University of Pennsylvania Medical School, Philadelphia, PA, USA. armstron@mail.med.upenn.edu
authors.forename: Carol L
authors.initials: CL
authors.lastname: Armstrong
authors.forename: Jill V
authors.initials: JV
authors.lastname: Hunter
authors.forename: David
authors.initials: D
authors.lastname: Hackney
authors.forename: Mayadah
authors.initials: M
authors.lastname: Shabbout
authors.forename: Robert W
authors.initials: RW
authors.lastname: Lustig
authors.forename: Bram
authors.initials: B
authors.lastname: Goldstein
authors.forename: Maria
authors.initials: M
authors.lastname: Werner-Wasik
authors.forename: Walter J
authors.initials: WJ
authors.lastname: Curran
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001284:Atrophy / Q000473:pathology; D001921:Brain / Q000473:pathology / Q000528:radiation effects*; D001932:Brain Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D011446:Prospective Studies; D011832:Radiation Injuries / Q000473:pathology*; D020266:Radiotherapy, Conformal; D013997:Time Factors