脳動静脈奇形に対するガンマナイフ治療10年後に症候性放射線壊死をきたした1例

Symptomatic Radiation Necrosis 10 Years after Gamma Knife Surgery for Arteriovenous Malformations: A Case Report

はじめに

　近年，脳動静脈奇形に対するガンマナイフ治療が盛んに行われている。その適応が拡がってきている印象があるが，照射後長期にわたるフォローアップを行っていると，大部分の症例で効果が得られている半面，合併症を呈して手術を要する症例も出てきている^1）。今回われわれは，脳動静脈奇形に対するガンマナイフ治療10年後に症候性放射線壊死をきたし開頭による手術治療を要し，術後，症状の改善が得られた症例を経験したので，文献的考察を加えて報告する。

Abstract

　We present a case of symptomatic radiation necrosis after gamma knife surgery for arteriovenous malformations (AVMs).　Initially, at the age of 30 years the patient was treated with gamma knife surgery.　Angiography performed 2 years after radiation therapy revealed that the AVMs were completely obliterated.　Five years later, the patient had a generalized convulsion and a computed tomography (CT) scan showed a cystic formation in the irradiated area.　The patient was treated with a cyst-peritoneal (CP) shunt.　Thereafter, the patient seemed to be cured, but 5 years after CP shunt treatment, the patient had right hemiparesis, agraphia, and right hemianopsia.　Magnetic resonance imaging (MRI) revealed radiation necrosis in the left parietooccipital region and midline shift of the brain.　The patient was operated on and the hyalinized nidus and CP shunt tube were removed.　The patient fully recovered from the symptoms and resumed work.

(Received: September 28,2009,Accepted: December 25,2009)