Cerebral Cortex Regions Selectively Vulnerable to Radiation Dose-Dependent Atrophy.

Int J Radiat Oncol Biol Phys 2017 04 6;97(5):910-918. Epub 2017 Jan 6.

Department of Radiation Medicine and Applied Sciences, University of California, San Diego, La Jolla, California. Electronic address:

Purpose And Objectives: Neurologic deficits after brain radiation therapy (RT) typically involve decline in higher-order cognitive functions such as attention and memory rather than sensory defects or paralysis. We sought to determine whether areas of the cortex critical to cognition are selectively vulnerable to radiation dose-dependent atrophy.

Methods And Materials: We measured change in cortical thickness in 54 primary brain tumor patients who underwent fractionated, partial brain RT. The study patients underwent high-resolution, volumetric magnetic resonance imaging (T1-weighted; T2 fluid-attenuated inversion recovery, FLAIR) before RT and 1 year afterward. Semiautomated software was used to segment anatomic regions of the cerebral cortex for each patient. Cortical thickness was measured for each region before RT and 1 year afterward. Two higher-order cortical regions of interest (ROIs) were tested for association between radiation dose and cortical thinning: entorhinal (memory) and inferior parietal (attention/memory). For comparison, 2 primary cortex ROIs were also tested: pericalcarine (vision) and paracentral lobule (somatosensory/motor). Linear mixed-effects analyses were used to test all other cortical regions for significant radiation dose-dependent thickness change. Statistical significance was set at α = 0.05 using 2-tailed tests.

Results: Cortical atrophy was significantly associated with radiation dose in the entorhinal (P=.01) and inferior parietal ROIs (P=.02). By contrast, no significant radiation dose-dependent effect was found in the primary cortex ROIs (pericalcarine and paracentral lobule). In the whole-cortex analysis, 9 regions showed significant radiation dose-dependent atrophy, including areas responsible for memory, attention, and executive function (P≤.002).

Conclusions: Areas of cerebral cortex important for higher-order cognition may be most vulnerable to radiation-related atrophy. This is consistent with clinical observations that brain radiation patients experience deficits in domains of memory, executive function, and attention. Correlations of regional cortical atrophy with domain-specific cognitive functioning in prospective trials are warranted.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ijrobp.2017.01.005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5403140PMC
April 2017
36 Reads

Publication Analysis

Top Keywords

radiation dose-dependent
20
cerebral cortex
12
radiation
9
patients underwent
8
radiation dose
8
dose-dependent atrophy
8
brain radiation
8
cortical thickness
8
primary cortex
8
cortical regions
8
rois tested
8
paracentral lobule
8
1 year afterward
8
cortical atrophy
8
cortex rois
8
regions radiation
8
inferior parietal
8
vulnerable radiation
8
selectively vulnerable
8
executive function
8

Altmetric Statistics

Similar Publications