以立體定位放射手術治療腦動靜脈畸形：高雄長庚紀念醫院之初步結果

　　　　　目的：報告本科單次李體定位放射手術治療腦部動靜脈畸形的初步結果。 材料與方法：從1994粘6月至1998粘4月，共有26位腦部動靜脈畸形病患在本科接受立 體定位放射手術。發病年齡由12歲至77歲（中值年齡為28.5歲）。我們以Siemens直線加 速器6MVX-ray治療，病變周圍劑量為10-18.73 Gy（中值為15 Gy），最小劑量為4.62-15.13 Gy（中值為11.88 Gy）最大劑量為13.33-27.95 Gy（中值為18.84 Gy）。平均病變體積為6.85 cm?纂]0.63-25.76，中值為5．32cm?纂^，有22位病患是以一個等中心點治療，治療弧度 數目為4到6個，有4位病患是以兩個等中心點治療，治療弧度數目為6到10個。我們評 估動靜脈畸形消退的程度以及放射線治療產生的副作用。 結果：以血管攝影或磁振造影追蹤21例之結果，一年動靜脈畸形完全消退率為33%，兩年 完全消退率為41%。二年完全消退率在最小劑量≦13和>13 Gy分別為17%不60% （p=0．0067）。 二年完全消退率在病變體積≦6和，6cm?臚嬪O為44%不34%（p=0.6507）。有73%（11/15） 病變體積≦6 cm?蘆滲f患之最小劑量╱治療劑量比值>85%，相反地只有27%（3/11）病變體 積> 6 cm?蘆滲f患之最小劑量╱治療劑量比值>85%（p=0.02）。在多變數分析方面，唯一和 完全消退率有顯著相關的因素是最小劑量（P=0.0495）。有1位病患在治療完5個月發生顱 內出血。有2位病患在治療完14個月至21個月（中值期為17.5個月）在磁振造影追蹤發 現有放射線治療產生的副作用。 結論：體積和最小劑量可能影響腦部動靜脈畸形的消退率。參考文獻的報告，本科的完全消 退率較某些報告為低，劑量較低可能是原因。適當的把劑量提高可能可以改進治療效果。
　　　　　Purpose: For reporting the preliminary result of brain arteriovenous malformation (AVM) treated with single fraction stereotactic radiosurgery. Materials and Methods: From June 1994 through April 1998, 26 patients with brain AVM Received stereotactic radiosurgery. The age of patients ranged from 12 to 77 years old (median: 28.5). We used 6 MV X-ray Siemens linear accelerator. The median prescribed dose was 15 Gy (range: 10-18.73 Gy) to the nidus margin. The minimal dose ranged from 4.62 to 15.13 Gy (median 11.88 Gy). The maximal dose ranged from 13.33 to 27.95 Gy (median 18.84 Gy). The mean target volume was 6.85 cm (range: 0.63-25.76). Twenty-two patients were treated with one isocenter (4-6 arcs), 4 patients with 2 isocenters (6-10 arcs). We evaluated the response rate and radiation-induced complication. Results: The follow-up angiogram or MRI studies in 21 patients revealed the complete Obliteration rates in 1 and 2 years were 33% and 41%, respectively. With the minimal dose of ≦13 and >13 Gy, the 2-year complete obliteration rate was 17% and 60%, respectively (p = 0.0067). The 2-year complete obliteration rate was 44% and 34% with target volume ≦6 and > 6 cm?? (p = 0.6507), respectively. Higher ratio (> 85%) of minimal dose to prescribed dose was noted in 73% (11/15) and 27% (3/11) of the patients whose target volume was ≦6 and > 6 cm?? (p = 0.02), respectively. In multivariate analysis, minimal dose was an only significant factor for complete obliteration (p = 0.0495). One patient had hemorrhage 5 months after radiosurgery. Two patients had radiation-induced complications on MRI 14 to 21 months later after radiosurgery. Conclusion: Target volume and minimal dose may influence the obliteration rate of brain AVM. According to literature review, the complete obliteration rates in our series were lower than some reports. Lower prescribed doses may be the cause. Higher doses may improve the response rate.