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Irradiation
After Surgically Induced Brain Injury in the Rat: Timing in Relation to Severity
of Radiation Damage
Selcuk Peker,
Ufuk Abacioglu, Ibrahim Sun, Meral Yuksel, M. Necmettin
Pamir
Department of Neurosurgery, Marmara University,
Istanbul, Turkey [S.P., I.S., M.N.P.]; Department of Radiation Oncology, Marmara
University, Istanbul, Turkey [U.A.]; Department of Biochemistry, Medical
Faculty, Marmara University, Istanbul, Turkey [M.Y.].
Address for offprints: Selcuk Peker,
Atasehir 48 ada Mimoza 2/17, D: 22, K. Bakkalkoy 34758,
Istanbul, Turkey; Tel.: +90-216-3264559; Fax: +90-216-3057961; E-mail: peker@atlas.net.tr.
The aim
of this study was to evaluate how timing of irradiation after brain surgery in
rats relates to overall extent of brain radiation damage.
Extent of injury was determined according to lipid peroxidation
(malondialdehyde; MDA) levels in brain tissue.
Thirty female rats were randomly assigned to five equal groups (Groups A–E).
Four groups underwent trephination and scalpel hemisection of right frontal
lobe.
Rats in Groups B and D received 25 Gy cranial irradiation in a LINAC system at
10 and 20 days after surgery, respectively.
Twenty-four hours later they were killed and their right frontal lobes were
removed for lipid peroxidation determination.
Groups A and C were not irradiated; these groups were killed and had their
frontal lobes removed on day 11 and day 21 post-surgery, respectively.
The remaining six animals (Group E, sham surgery) underwent trephination only,
and were killed and had their frontal lobes removed 24 h later.
There
was a significant difference between the mean MDA levels in the control group
and Group D, and between the levels in Group B and Group D (P
< 0.05 for both).
The difference between the mean for Group A and the mean for Group B was even
more significant (P <
0.01).
The most striking differences ere between the control group and Group B, and
between Group B and Group C (P < 0.001 for both).
The data
from this rat model suggest that, in humans, starting radiotherapy early (1–2
weeks) after debulking of a brain tumor may result in significantly higher
levels of tissue damage than if the radiation is started 3 weeks or more
postoperatively.
Further experimental research is needed to project these findings in rats to
human subjects.
Keywords: brain,
free radicals, injury, lipid peroxidation, radiation, surgery
Copyright ©
2004 Kluwer Academic Publishers.
All rights reserved
Source: http://ipsapp009.kluweronline.com/IPS/content/ext/x/J/5042/I/123/A/5/abstract.htm
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