title: Long-term outcome of proton beam radiosurgery for arteriovenous malformations larger than 30 mm in diameter.
abstract: The effectiveness of proton beam (PB) radiosurgery for large lesions is greater than for other treatment modalities. At our institute, PB radiosurgery is used to treat arteriovenous malformations (AVMs). We report the outcome of PB radiosurgery for AVMs over a period of 15 years, focusing on the efficacy of PB radiosurgery combined with embolization for AVMs ≥30 mm in diameter. We retrospectively analyzed 11 patients with AVMs ≥30 mm in diameter who were treated with PB radiosurgery between June 1990 and September 2005 at the Proton Medical Research Center of the University of Tsukuba. The mean irradiation dose was 25.3 gray-equivalent, and the mean duration of clinical follow up was 134.2 months (median 138 months). Pre-radiosurgical embolization was performed in all cases. Complete obliteration was achieved in 9 of the 11 patients. One patient experienced post-radiosurgical hemorrhage, and 1 patient experienced radiation-related aggravation of clinical symptoms due to radiation necrosis. Eight patients had excellent outcomes. The multimodal therapy approach of combining pre-radiosurgical embolization and PB radiosurgery for AVMs yielded a favorable outcome for AVMs ≥30 mm in diameter. Thus, PB radiosurgery is a viable treatment option for AVMs ≥30 mm in diameter.
authors.affiliation: Department of Neurosurgery, Institute of Clinical Medicine, Graduate School of Comprehensive Human Science, University of Tsukuba, Ibaraki, Japan.
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Ito
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Okumura
authors.forename: Kensuke
authors.initials: K
authors.lastname: Suzuki
authors.forename: Akira
authors.initials: A
authors.lastname: Matsumura
authors.forename: Koichi
authors.initials: K
authors.lastname: Tokuue
authors.forename: Koji
authors.initials: K
authors.lastname: Tsuboi
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003131:Combined Modality Therapy / Q000379:methods; D004621:Embolization, Therapeutic / Q000379:methods; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000150:complications / Q000473:pathology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D061766:Proton Therapy; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000453:epidemiology; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods; D012189:Retrospective Studies; D013995:Time; D016896:Treatment Outcome; D055815:Young Adult; D011522:Protons
chemical_list: D011522:Protons