Early Response to Radiation Therapy without Surgical Intervention in a Giant Cavernous Sinus Hemangioma with Hydrocephalus: A Case Report.

Cavernous sinus hemangioma (CSH) is a rare vascular malformation, arising from the cavernous sinus. Because of its anatomically complex location, a large lesion can cause a variety of symptoms due to cranial nerve compression. A 69-year-old woman with an unsteady gait was admitted to our hospital, and magnetic resonance imaging revealed an extra-axial giant tumor in the cavernous sinus and enlarged ventricles. A radiographic diagnosis of CSH was made. As the risk of surgical removal was considered high, the patient underwent intensity-modulated radiation therapy of 50.4 Gy in 28 fractions. The size of the tumor decreased markedly over time, and the symptoms improved soon after treatment. A 61.8% reduction in tumor size was confirmed immediately after irradiation, and a 75.9% reduction was revealed at a follow-up visit one year later. We reported a case of a giant CSH with hydrocephalus, where tumor shrinkage was confirmed immediately after radiation therapy, and the symptoms of hydrocephalus improved without surgical intervention.