Radiation necrosis of the brain and radiation-induced cerebrovasculopathy.

Thirteen patients with radiation necrosis and 6 patients with occlusive radiation-induced cerebrovasculopathy were reviewed. Computed tomography (CT) demonstrated low attenuation with a mass effect and irregular contrast enhancement in the radiation necrosis. The mass effect and the contrast enhancement decreased gradually. Angiography showed an avascular mass, generalized narrowing of the ipsilateral arteries and slow blood circulation in 3 cases. Radiation-induced vasculopathy appeared as localized stenosis and irregular walls of the arteries within the irradiated area. In cases with radiation vasculopathy accompanied by sufficient collateral blood flow brain damage was rarely demonstrated by CT. In patients with radiation-induced vasculopathy the lesion was not associated with signs of radiation necrosis.