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Radiobiology in the CNS:
the vascular effect (SRS)
•
Mainly for the case of benign lesions (AVM and
meningioma, namely) large parte of the effect is
determined by the combination of:
Citotoxic effect
of the high dose of radiation with direct
double strand DNA damage
Vascular injury
with doubled number of apoptotic cells in the
first 48 hours
Such a vascular effect is seen on tumor and AVM, but
not in
normal vessels
(different vascular/endothelial
radiosensitivity)
The probability of vascular damage is directly proportional to
the fraction dose (particularly when higher than 10 Gy!!!)
High dose induces reduction of vascular mass and increase of
vascular permeability
Park and Griffin, Rad Res., 2012