頁籤選單縮合
題名 | 電子射束遮擋照野之劑量特性=Dosimetery Characteristics of Cerrobend Blocked Electron Beams |
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作者 | 林賢岳; 黃旼儀; 湯人仰; 黃英明; 黃志仁; 何耀輝; 郭珍妮; | 書刊名 | 放射治療與腫瘤學 |
卷期 | 5:4 1998.12[民87.12] |
頁次 | 頁311-316 |
分類號 | 416.36 |
關鍵詞 | 電子射束治療; Cerrobend 遮擋鉛塊; 百分深度劑量曲線; Electron beam therapy; Cerrobend cutout blocks; Percentage depth dose curves; |
語文 | 中文(Chinese) |
中文摘要 | 目的:本研究以CERROBEND 鉛合金,針對CL-2100CD直線加速器開壁式各限光筒尺 寸, 製成邊長以 1cm 為級數變化之正方形庶擋塊,測量在射源至皮膚表面為 100 cm 時, 各縮小照野之百分深度劑量曲線,以觀察並探討縮小照野面積的百分深度劑量曲線變化之情 形及臨床應注意的事項。 材料與方法:以 CERROBEND 鉛合金,依各限光筒尺寸製作邊長以 1cm 為級數之正方形中空遮擋塊,依次置於 Varian CL-2100CD 直線加速器電子限光筒底部 , 以 Nucletron 三度空間水假體連接 Scanditronix p 型半導體偵測器,測量各擋塊照野 電子射束能量分別為 6,9,12,16.20 MeV 射束之百分深度劑量曲線,觀察各能量各照野之最 高劑量點 (D),90%,80% 劑量點之深度,及電子束射程 (Rp) 之變化情形。 結果:最高劑 量點 (D),90%,80% 劑量點深度之變化情形為:當照野面積縮小到 1 × 1 cm �揹氶A所有 能量射束之最高劑量點皆位於 0.5 ∼ 0.8cm 之間,不論限光筒大小為何,90% 劑量點深度 的變化情形為:6MeV 從照野 3 × 3cm �插AMeV 從 1.5 × 4.5cm �插A12MeV 從 6 × 6cm �插A16MeV 從 8 × 8 cm �插A20MeV 則從 10.5 ×10.5 cm �揖H下開始降低。 結論:臨床上以 不規則形 CERROBEND 鉛合金執行小照野電子射束治療時,其最高劑量點, 90%, 80% 劑量 點之深度將會變小,因此,臨床上在決定射束能量時,若照野面積小於各能量、各劑量的降 低點時,應先注意治療擋塊之大小,查得其 90%,80% 劑量點深度,再決定能量。 |
英文摘要 | Purpose:The percentage depth dose changes of high energy electron beams generated from Varian CL2100C/D linear accelerator collerated with various sizes of cutout blocks were measured at 100cm source-to-sruface distance. The clinical significance was discussed. Materials and Methods:CERROBEND cutout blocks were made for open-wall MLC type applicators. The step size of the square cutout is 1 cm. The percentage depth dose curve were scanned with Nucletron 3-D water phantom system connected with Scanditronix p-type semiconductor chamber. The electron energies were ranged from 6,9,12,16 and 20 MeV. The depths of D, D, D �� and R �d were measured to observed its variation with cutout size. Results:The depths of D were located at 0.5 to 0.8 cm at the cutout size equal to 1 × 1 cm �� for all energies. The decrement points of the four parameters for each energy were the same in all cone sizes. The decrement cutout sizes were 3 × 3 cm �� for 6 MeV, 4.5 × 4.5 cm �� for 9 MeV, 6 × 6 cm �� for 12 MeV, 8 × 8 cm �� for 16 MeV and 10.5 × 10.5 cm �� for 20 MeV. Conclusions:The depth of D, 90% and 80% depth dose will shift to surface direction when the irradiate area was decreased. It is mentioned clinically that the 90% depth should be examined before energy selection for tumor treatment. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。