J Korean Neurosurg Soc.  1997 Nov;26(11):1502-1512.

Pathological Changes in the Rat Brain after Experimental Intraoperative Radiation

• Kim JH
• Chung YG
• Kim HK
• Kim CY
• Lee HK
• Lee KC

Abstract

The aim of this study was to investigate the response of normal brain tissue to intraoperative irradiation. Light microscopic studies were performed in order to evaluate cellular tissue change such as loss of molecular layer, difficulty in identifying six normal cortical layers, increased reactive gliosis, vascular endothlial cell proliferation and fibrosis in the cerebral cortex and immunohistochemical study used glial fibrillary acidic protein(GFAP). After craniectomy, the right hemisphere of 24 Sprague-Dawley rats was exposed to a single 10Gy dose of gamma rays for 4 minutes. The radiation effect was assessed 1 week(group A), 2 weeks(group B), 1 month(group C), 1.5 months(group D), and 2 months(group E) after irradiation ; degeneration of nerve cells was evident after 2 weeks. One month after irradiation(group C), the following findings were noted : loss of molecular layer, difficulty in identifying six normal cortical layers, increased reactive gliosis, vascular endothelial cell proliferation and fibrosis in the cerebral cortex. Two months after irradiation(group E), necrotic change was seen in the cortex, in addition to the findings described in group C. In conclusion, the following pathological changes were evident according to time, after intraoperative irradiation : loss of molecular layer, difficulty in identifying six normal cortical layers, increased reactive gliosis, vascular endothelial cell proliferation and fibrosis in the cerebral cortex. To clarify the late effects of intraoperative radiotherapy(IORT), and to compare these to the pathological changes seen after exopsure to other irradiation modalities, further study is needed.

Keyword

Intraoperative irradiation; GFAP; Reactive gliosis; Radiation injury

MeSH Terms

Animals
Brain*
Cell Proliferation
Cerebral Cortex
Endothelial Cells
Fibrosis
Gamma Rays
Gliosis
Neurons
Radiation Effects
Radiation Injuries
Rats*
Rats, Sprague-Dawley