摘要
本研究之目的主要在測量不同機重及能量放射治療之表面劑量百分比。包括三家醫院共四檯鈷六十及乙檯10MV直線加速器。所使用的測量儀器為capintec薄窗型游離腔並配合適當的聚苯乙烯(polystyrene)材質假體。測量時射源至假體表面距離(SSD)保持80 cm或65 cm，照野由5*5 cm的二次方至25*25 cm的二次方且同一能量參考深度均相同。由測量結果得知，對鈷六十而言，SSD 80 cm時其表面劑量由5*5 cm的二次方的20%至25*25 cm的二次方的59%。SSD為65 cm則其表面劑量較SSD 80 cm者高，且數值隨照野之增大而增加。10MV直線加速器之表面劑量由5*5 cm的二次方的9%至25*25 cm的二次方的21%。
並列摘要
This is a study about surface dose on different teletherapy unis. We measured the surface dose of four Co-60 and one linear accelerator machine in three hospitals. The instrument we used included capintec thin window type ion chamber and solid phantom of polystyrene. In this experiment we set the source to surface distanc at 80 CM and 65 cm, field size from 5*5 to 25*25 cm square and set ion chamber at the same energy. Judging from this experiment, we obtained some results. The surface ddose of Co-60 increase from 20% to 59% when field size increase from 5*5 cm square to 25*25 cm square. Besides. there was little difference for different machines. Similary. the surface dose increased from 9% to 21% for linear accelerator. In addition. the surface dose set at SSD 65 cm was higher than that at SSD 80 cm. when the distance of source to surface was shortened, collimator closed to surface of phantom. Low energy scatter radiation and electron contamination which came from collimator made the surface dose increase. Surface dose decreased when energy increased. so low energy radiation is suitable to treat skin cancer. On the contrary, high energy radiation would reduce the surface dose.
延伸閱讀
- 劉國基、蕭安成、趙敏、梁基安、楊世能、蘇經雄、施文彬、陳信雄（2007）。強度調控放射治療之表面劑量測量。放射治療與腫瘤學，14(2)，113-121。https://doi.org/10.6316/TRO/200714(2)113
- Wang, K. W., Ma, H. K., Hsiung, C. Y., Lin, Y. J., Lin, J. P., Li, K. L., & Lai, Y. C. (2011). 強度調控放射治療技術低監控單位之射束品質及劑量探討. 台灣應用輻射與同位素雜誌, 7(2), 51-58. https://doi.org/10.29832/TJARI.201106.0001
- 許芳裕、游澄清、陳拓榮、邱美晴、黃奕祥、蔡欣霓、劉鴻鳴（2007）。中子治療試驗之輻射劑量評估。台灣應用輻射與同位素雜誌，3(3)，327-332。https://doi.org/10.29832/TJARI.200709.0001
- 張凱銘（2015）。Researching the Theory of Soft Balancing。問題與研究，54(2)，101-123。https://doi.org/10.30390/ISC.201506_54(2).0004
- 姚俊興、陳冰虹（2006）。Treatment of Epilepsy。台灣醫學，10(6)，721-726。https://doi.org/10.6320/FJM.2006.10(6).08