腦膜動靜脈瘻管約占顱內血管畸形的 10-15%，其治療需要多專科團隊參與，包含手術， 血管栓塞及放射手術。我們在此報告一例 52 歲女性，因左耳發生搏動性耳鳴三個月，且對藥 物治療無效，接受血管攝影後發現為左側乙狀靜脈竇之腦膜動靜脈瘻管所致，其瘻管沒有發生 腦皮質靜脈回流。此病例因不適合手術及血管栓塞，故被轉介至放射腫瘤科接受立體定位放 射手術。我們使用熱塑形面具固定病人，而後病人接受細切之核磁共振（有打顯影劑）及電 腦斷層攝影（不打顯影劑）。利用與電腦斷層影像融合之核磁共振影像畫出不正常之血管與瘻 管。放射手術之前，我們以即時X 光影像（on-board imager）取 2D 影像及錐束電腦斷層（cone beam CT images）進行影像導引，以校正擺位誤差。放射劑量由配備動態多葉準直儀之直線加 速器，五個非共面弧形射束給予 20 Gy，最高劑量為 21.9 Gy。病人之搏動性耳鳴約於放射手術 後兩個月時完全消失，而於放射手術後三及九個月追蹤之核磁共振影像及一年後追蹤之血管攝 影發現腦膜動靜脈瘻管已完全阻塞，且病灶周邊無可見的影像變化；放射手術後一年時亦無副 作用之報告。

Dural arteriovenous fistulas (DAVFs) account for approximately 10% to 15% of intracranial vascular malformations. The current management of cerebral DAVFs includes a multimodal approach involving surgery, endovascular therapy, and stereotactic radiosurgery (SRS). A 52 years-old female suffered from progressive pulsatile tinnitus of left ear for about 3 months and her symptoms didn’t response to medical treatment. Her angiography showed numerous DAVFs without cortical venous reflux in left sigmoid sinus. She was referred to Radiation Oncology clinic for SRS, because surgery or endovascular therapy was not recommended. A thermoplastic mask was done for patient fixation. Then, the patient underwent a thin-sliced contrast-enhanced MRI exam with contrast enhancement and CT simulation without contrast enhancement. Abnormal fistulas and vessel were contoured on MRI images which were fused with CT images. Before SRS, pairs of orthogonal films and cone beam CT images which obtained by on-board imager were used for image guidance. Radiation dose was delivered with dynamic multileaf collimator in five non-coplanar arcs by a linear accelerator. The prescription dose was 20 Gy and the maximal dose was 21.9 Gy. The symptom of pulsatile tinnitus had been improved gradually since SRS and completely disappeared at about 2 months after SRS. Follow-up MRI at 3 and 9 months and angiography at 1 year after SRS suggested complete obliteration of DAVFs. No radiation-induced change at the perimeter of the lesion was observed by MRI or other chronic toxicity was reported at 1 year after SRS.