title: Dose-Dependent Cortical Thinning After Partial Brain Irradiation in High-Grade Glioma.
abstract: OBJECTIVE
  Radiation-induced cognitive deficits may be mediated by tissue damage to cortical regions. Volumetric changes in cortex can be reliably measured using high-resolution magnetic resonance imaging (MRI). We used these methods to study the association between radiation therapy (RT) dose and change in cortical thickness in high-grade glioma (HGG) patients.
  
  
  METHODS
  We performed a voxel-wise analysis of MRI from 15 HGG patients who underwent fractionated partial brain RT. Three-dimensional MRI was acquired pre- and 1 year post RT. Cortex was parceled with well-validated segmentation software. Surgical cavities were censored. Each cortical voxel was assigned a change in cortical thickness between time points, RT dose value, and neuroanatomic label by lobe. Effects of dose, neuroanatomic location, age, and chemotherapy on cortical thickness were tested using linear mixed effects (LME) modeling.
  
  
  RESULTS
  Cortical atrophy was seen after 1 year post RT with greater effects at higher doses. Estimates from LME modeling showed that cortical thickness decreased by -0.0033 mm (P<.001) for every 1-Gy increase in RT dose. Temporal and limbic cortex exhibited the largest changes in cortical thickness per Gy compared to that in other regions (P<.001). Age and chemotherapy were not significantly associated with change in cortical thickness.
  
  
  CONCLUSIONS
  We found dose-dependent thinning of the cerebral cortex, with varying neuroanatomical regional sensitivity, 1 year after fractionated partial brain RT. The magnitude of thinning parallels 1-year atrophy rates seen in neurodegenerative diseases and may contribute to cognitive decline following high-dose RT.
authors: Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California.
authors: Roshan
authors: R
authors: Karunamuni
authors: Department of Radiology, University of California San Diego, La Jolla, California.
authors: Hauke
authors: H
authors: Bartsch
authors: Department of Radiology, University of California San Diego, La Jolla, California.
authors: Nathan S
authors: NS
authors: White
authors: Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California.
authors: Vitali
authors: V
authors: Moiseenko
authors: Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California.
authors: Ruben
authors: R
authors: Carmona
authors: Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California.
authors: Deborah C
authors: DC
authors: Marshall
authors: Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California.
authors: Tyler M
authors: TM
authors: Seibert
authors: Department of Psychiatry, University of California San Diego, La Jolla, California.
authors: Carrie R
authors: CR
authors: McDonald
authors: Department of Radiology, University of California San Diego, La Jolla, California.
authors: Nikdokht
authors: N
authors: Farid
authors: Department of Radiology, University of California San Diego, La Jolla, California.
authors: Anithapriya
authors: A
authors: Krishnan
authors: Department of Radiology, University of California San Diego, La Jolla, California.
authors: Joshua
authors: J
authors: Kuperman
authors: Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California.
authors: Loren
authors: L
authors: Mell
authors: Department of Radiology, University of California San Diego, La Jolla, California.
authors: James B
authors: JB
authors: Brewer
authors: Department of Radiology, University of California San Diego, La Jolla, California.
authors: Anders M
authors: AM
authors: Dale
authors: Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California. Electronic address: jhattangadi@ucsd.edu.
authors: Jona A
authors: JA
authors: Hattangadi-Gluth
mesh_terms: D000328:Adult; D000368:Aged; D001284:Atrophy / Q000209:etiology / Q000473:pathology; D001921:Brain / Q000473:pathology / Q000528:radiation effects; D001932:Brain Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D002540:Cerebral Cortex / Q000473:pathology / Q000528:radiation effects*; D016371:Cranial Irradiation / Q000009:adverse effects* / Q000379:methods; D019583:Dose Fractionation, Radiation; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005910:Glioma / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013997:Time Factors