title: Morphometry-based measurements of the structural response to whole-brain radiation.
abstract: OBJECTIVE
  Morphometry techniques were applied to quantify the normal tissue therapy response in patients receiving whole-brain radiation for intracranial malignancies.
  
  
  METHODS
  Pre- and Post-irradiation magnetic resonance imaging (MRI) data sets were retrospectively analyzed in N = 15 patients. Volume changes with respect to pre-irradiation were quantitatively measured in the cerebrum and ventricles. Measurements were correlated with the time interval from irradiation. Criteria for inclusion included craniospinal irradiation, pre-irradiation MRI, at least one follow-up MRI, and no disease progression. The brain on each image was segmented to remove the skull and registered to the initial pre-treatment scan. Average volume changes were measured using morphometry analysis of the deformation Jacobian and direct template registration-based segmentation of brain structures.
  
  
  RESULTS
  An average cerebral volume atrophy of -0.2 and -3% 3% was measured for the deformation morphometry and direct segmentation methods, respectively. An average ventricle volume dilation of 21 and 20% was measured for the deformation morphometry and direct segmentation methods, respectively.
  
  
  CONCLUSIONS
  The presented study has developed an image processing pipeline for morphometric monitoring of brain tissue volume changes as a response to radiation therapy. Results indicate that quantitative morphometric monitoring is feasible and may provide additional information in assessing response.
authors.affiliation: Department of Imaging Physics, The University of Texas M.D. Anderson Cancer Center, Houston, TX, 77030, USA, dtfuentes@mdanderson.org.
authors.forename: D
authors.initials: D
authors.lastname: Fuentes
authors.forename: J
authors.initials: J
authors.lastname: Contreras
authors.forename: J
authors.initials: J
authors.lastname: Yu
authors.forename: R
authors.initials: R
authors.lastname: He
authors.forename: E
authors.initials: E
authors.lastname: Castillo
authors.forename: R
authors.initials: R
authors.lastname: Castillo
authors.forename: T
authors.initials: T
authors.lastname: Guerrero
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000473:pathology / Q000528:radiation effects*; D001932:Brain Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D016371:Cranial Irradiation; D018450:Disease Progression; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult