Cerebral infarction with ICA occlusion after Gamma Knife radiosurgery for pituitary adenoma: A case report.

Cranial irradiation may lead to accelerated atherosclerotic changes to small or medium sized arteries, but stroke associated with pituitary irradiation is not frequent. A patient treated with Gamma Knife radio-surgery (GKRS) for a pituitary adenoma suffered a cerebral infarction with internal carotid artery occlusion 4 years after radiosurgery. The patient was a 35-year-old male presenting with a visual disturbance. Endocrinological tests were normal. MRI revealed a 4.3 by 4.3 cm diameter invasive macroadenoma of the pituitary, projecting toward the suprasellar region and with cavernous sinus involvement with encasement of both internal carotid arteries (ICAs). GKRS was performed for residual tumor after a transcranial resection. The maximum dose was 40 Gy and the dose to the right carotid artery was below 20 Gy. The delayed hemiparesis was accompanied by a right capsular lacunar infarct shown on MRI. The images also showed a marked reduction in tumor size. Total, right ICA occlusion was confirmed by Doppler ultrasound. The patient had no history or signs of heart disease or metabolic disorder which could predispose to cerebrovascular