Potentially obstructive:
(1) premature atherosclerosis
(2) mineralizing microangiopathy (with dystrophic calcification)
(3) vascular occlusion from intimal and/or mural fibrosis
(4) degeneration of vascular wall layers (disruption of elastica, damage to endothelium)
Proliferative lesions:
(1) radiation-induced cavernous hemangioma (RICH, angiomatous malformation)
(2) angiosarcoma
Obstructive lesions can result in ischemic injury. In the brain this can result in stroke. Benign vascular proliferations may be mistaken for recurrent tumor, while angiosarcomas behave as malignant tumors.
Diagnostic features:
(1) The vascular change is present within a radiation field.
(2) Exclusion of alternative diagnosis.
It should not be explained solely as a pre-existing vascular lesion. Some vasculopathies may appear some time after the radiation exposure.
