Clinical, Radiologic, and Pathologic Findings in Brain Radiation Injury
| Stage (time to onset) | Symptoms | MRI/CT | PET | Pathology |
|---|---|---|---|---|
| Acute (hours to weeks) | Related to mass effect and ensuing increased ICP (headache, vomiting, altered consciousness) | Edema; enhancing tumor mass | Hypometabolism | Edema; demyelinating plaques; gray–white junction fibrin exudate; hemorrhageic coagulation necrosis and vascular proliferation |
| Early delayed (weeks to 4 mo) | Mixed 1 and 3 | White matter cyst formation | Hypometabolism | Mixed 1 and 3 |
| Late delayed (4 mo to years) | Focal neurologic deficits depending on the size and location of the lesion | Cortical atrophy Diffuse periventricular edema Expansile enhancing mass with focal hyperintensity on T2 and proton density images | Hypometabolism | Fibrinoid necrosis of the medium and small arteries with vascular proliferation; swollen gyri; hemorrhagic coagulation necrosis of the gray matter; white matter affected more than gray; axonal swelling, multifocal demyelination, hyalinization, and reactive gliosis |
| Chronic | Stable focal neurologic deficits as well as global effects causing personality changes and dementia | Vascular dystrophic calcification with cystic changes; cortical atrophy; telangioectasia | Hypometabolism | Reactive gliosis; subcortical cyst formation; vasculitis, arteritis, enhanced atherosclerosis, and vascular dystrophic calcification with cystic changes |