Multiple cysts in the cerebral white matter: a rare complication of whole brain radiation therapy.

We describe a patient with multiple cysts in the cerebral white matter, several years after whole brain radiation therapy (WBRT) for a solitary cerebellar metastasis of a lung carcinoma. MR images of the brain show diffuse white matter changes, 1 year after radiation, and cyst formation in the white matter, starting 3.5 years later. We conclude that cysts in the cerebral white matter can be a late stage of white matter damage after whole brain radiation therapy in long-term survivors with brain metastases.