目的：分析本院使用X光刀治療腦部動靜脈畸形的治療效果。材料及方法：從一九九六年到兩千零四年，共有一百一十七個腦部病灶患者於本院接受腦部X光刀治療。中位數追蹤期為四十二個月（範圍：六至一百零七個月）。其中共有二十六位腦部動靜脈畸形患者。依性別分，共有七位女性及十九位男性。接受X光刀時的平均年齡為二十九歲（範圍：八至七十一歲）。依Spetzler-Martin分數來分，各別為：九位病人為一分，五位病人為兩分，四位病人為三分及八位病人為四分。腦部動靜脈畸形平均標的體積為七點九西西。平均標的周邊劑量為十三格雷。結果：沒有病人於收案期間死亡。二十四位病人於X光刀後有接受腦部核磁共振檢查，八位有接受傳統腦部血管攝影檢查。粗治癒率為百分之六十二點五(5/8)。X光刀後腦部動靜脈畸形於傳統血管攝影時顯現完全阻塞之中位時間為六十三個月（範圍：三十三至七十二個月）。X光刀前的出血率為百分之六十一點五；X光刀後的出血率為百分之七點七。共有三位病人於接受X光刀後產生永久性腦部壞死症狀（百分之十一點五）。這三位病人皆是早期治療的病患。影響腦部壞死的危險因子為治療標的體積超過七西西（P值等於0.002）及X光刀最大治療孔徑大於三公分（P值等於0.004）。結論：本院使用X光刀治療腦部動靜脈畸形的治療效果與文獻上報導結果為可比較的。然而本院的治療數目仍少，需日後更多病人數及更長之追蹤期以便獲得更強而有力的結論。

Introduction: To report our preliminary treatment result of AVMs treated by Linac-based Stereotactic Radiosurgery (X-knife). Materials and Methods: From 1996 to 2004, there were 117 patients treated by X-knife for their brain lesions in this hospital. The median follow-up time was 42 months (range: 6-107 months). These included 26 cerebral AVMs. There were 7 female and 19 male. The mean age at time of SRS was 29 years (range, 8-71 years). For Spetzler-Martin score distribution, there were score 1 (n=9), score 2(n=5), score 3(n=4) and score 4(n=8), respectively. Mean target volume was 7.9 c.c.. Mean peripheral or minimal dose was 13 Gy. Results: No patient had died during the study interval. Twenty-four patients had at least one MRI/MRA follow-up and 8 had catheter angiography. The crude rate of cure was 62.5% (5/8). The crude rate of combined total and partial obliteration was 79.2% (19/24). Median time to complete disappearance of the nidus on MRI/MRA was 28 months (range, 1-82). Median time to complete obliteration verified by conventional angiography was 63 months (range, 33-72). Hemorrhage rate before and after radiosurgery were recorded in 61.5% and 7.7%, respectively. Three patients (11.5%) had brain necrosis with permanent neurological defects and all were treated in the early stage in this study. Significant risk factors for brain necrosis showed target volume more than 7c.c. (P=0.002) and maximum cone size more than 3.0 cm (P=0.04). Conclusion: The results of AVM treated by Linac-based SRS in our institute were comparable with other reported data. However, larger sample size with a longer follow-up is needed for a more conclusive comment.