Delayed cerebrovascular consequences of therapeutic radiation. A clinicopathologic study of a stroke associated with radiation-related carotid arteriopathy.

A young woman, successfully treated for Hodgkin's disease with radiation and MOPP chemotherapy, incurred a devastating stroke months after radiation therapy to the neck and other areas. There was no premonitory clinical history of cerebrovascular attacks. Autopsy showed unilateral thrombotic occlusion of the internal carotid artery unassociated with neoplastic or fibrotic annular constriction of the vessel. There was medial thickening and fibroblastic proliferation within the carotid artery. Areas of focal elastic membrane degeneration involved the cervical portions of the carotid. Thrombus was organized to the damaged vessel wall and was propagated into the intracranial vessels. Aneurysm formation and arterial hemorrhages were absent. These vascular changes occurred in an area of extensive radiation (7200 rads). Pathoanatomical studies in this patient indicate that radiation-induced vascular changes were associated with a "delayed" stroke.