title: Formation and Rupture of the Internal Carotid Artery Aneurysm after Multiple Courses of Intensity-Modulated Radiation Therapy for Management of the Skull Base Ewing Sarcoma/PNET: Case Report.
abstract: Background Aneurysm formation after stereotactic irradiation of skull base tumors is rare. The formation and rupture of an internal carotid artery (ICA) aneurysm in a patient with skull base Ewing sarcoma/primitive neuroectodermal tumor (PNET), who underwent surgery followed by multiple courses of intensity-modulated radiation therapy (IMRT) and chemotherapy, is described. Case Description A 25-year-old man presented with a sinonasal tumor with intraorbital and intracranial growth. At that time cerebral angiography did not reveal any vascular abnormalities. The lesion was resected subtotally. Histopathologic diagnosis was Ewing sarcoma/PNET. The patient underwent multiple courses of chemotherapy and three courses of IMRT at 3, 28, and 42 months after initial surgery. The total biologically effective dose delivered to the right ICA was 220.2 Gy. Seven months after the third IMRT, the patient experienced profound nasal bleeding that resulted in hypovolemic shock. Angiography revealed a ruptured right C4-C5 aneurysm and irregular stenotic changes of the ICA. Lifesaving endovascular trapping of the right ICA was done. The patient recovered well after surgery but died due to tumor recurrence 6 months later. Conclusion Excessive irradiation of the ICA may occasionally result in aneurysm formation, which should be borne in mind during stereotactic irradiation of malignant skull base tumors.
authors.affiliation: Faculty of Advanced Techno-Surgery, Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Tamura
authors.forename: Kasei
authors.initials: K
authors.lastname: Kogo
authors.forename: Osamu
authors.initials: O
authors.lastname: Masuo
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Oura
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Koji
authors.initials: K
authors.lastname: Fujita
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Nakao
authors.forename: Yuji
authors.initials: Y
authors.lastname: Uematsu
authors.forename: Toru
authors.initials: T
authors.lastname: Itakura
authors.forename: Mikhail
authors.initials: M
authors.lastname: Chernov
authors.forename: Motohiro
authors.initials: M
authors.lastname: Hayashi
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Muragaki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Iseki
keywords: Ewing sarcoma/PNET; aneurysm formation; complication; intensity-modulated radiation therapy; malignant skull base tumor; radiation-induced aneurysm