質子束在水中橫向寬度及深度劑量曲線的量測與模擬

簡易檢索 / 詳目顯示

回結果列表

研究生：	蔡綉吟 Siou-Yin Cai
論文名稱：	質子束在水中橫向寬度及深度劑量曲線的量測與模擬 Proton Beam Lateral Width and Depth Dose Curve in Water Measurements and Modeling
指導教授：	陳鎰鋒 A. E. Chen
口試委員:
學位類別：	碩士 Master
系所名稱：	理學院 - 物理學系 Department of Physics
論文出版年：	2013
畢業學年度：	101
語文別：	中文
論文頁數：	64
中文關鍵詞：	質子治療、質子束在水中、橫向分佈、筆束狀質子束
外文關鍵詞：	proton therapy, proton beam in water, lateral development, proton pencil beam
相關次數：	點閱：18 下載：0
分享至:	分享至facebook 分享至twitter

查詢本校圖書館目錄查詢臺灣博碩士論文知識加值系統勘誤回報

質子治療，主要是利用質子束的深度劑量曲線前低後面急劇上升後又急劇下降的優點，而質子束高劑量區的深度位置分布與質子束的能量及能量的不準度E有關，這在治療癌症上來說可以利用控制能量大小將劑量準確的投擲在入射方向上腫瘤所在位置；但因腫瘤是立體的其周遭都會有正常的細胞，因此對垂直入射方向上的橫向劑量的分布情況也是在治療上必須考量的因素之一。
本研究主要目的是建立一套模型，可以精確描述質子束在水中的深度劑量曲線及橫向劑量隨深度變化情形。所使用的方法是在質子束出口處及水箱內各放置一個自製的具有空間解析度為一毫米的條狀探測器，分別作為監控及量測使用。首先利用監控探測器得知在該位置質子束的大小及形狀，再由探測器在水中量測深度劑量曲線與Geant4模擬交叉比對得知質子束的能量。接著利用探測器在空氣中不同深度下量測橫向寬度分佈結果再與Geant4模擬交叉對照，找出質子束的發散角。最後再將所得到的能量與發散角模擬質子束在水中不同深度下的橫向寬度分佈並與實驗量測結
果相互比較。
利用此方法分別對在日本大阪大學核物理研究中心(Reaserch Center for Nuclear Physics，RCNP)質子束能量100MeV及200MeV兩次實驗結果比較。這兩次實驗，在實驗上的架設、質子束形狀寬度、加速器設定皆不同的情況下，在水中橫向寬度分佈演變的趨勢實驗結果與模擬甚為吻合。證明了此套方法的正確性及模擬系統的整體的物理機制及參數設定適用於深度劑量曲線及質子束橫向寬度變化模擬的需求。

Proton therapy takes the advantage of Bragg curve which delivers higher dose at depth before it stops abruptly. The less addressed point is its lateral dose distribution which is relevant to the healthy cells surround tumor.

The main purpose of this study is to establish a model that can accurately estimate depth dose distribution and lateral dose distribution of a narrow proton beam in different depths.

Parameters of proton beam are obtained by comparing experimental measurements with Geant4 simulations. Beam size and shape are measured by monitoring detector and proton beam energy can be learnt from depth-dose curve in water, by comparing measurement and simulation. Results from experiments prefer that proton beam propagates with a dispersion angle. Such dispersion angle is obtained by comparing measurement and simulation result of lateral dose development in air. Finally, these parameters are fed into simulation of proton beam propagation in water. Development of lateral dose in water at different depth is compared with experimental result. They agree well with proton energies of 100 and 200 MeV respectively. A reliable model has been established to estimate depth dose distribution and lateral dose distribution of a narrow proton beam in water.

At the same time, previous study claims discrepancy between Geant4 simulation and experiment in lateral dose development in water. Our study shows such discrepancy disappears if dispersion angle has been introduced in proton beam propagation.

中文摘要....................................... i
Abstract..................................... ii
謝誌.......................................... iii
目錄.......................................... iv
圖目錄......................................... v
表目錄..........................................viii
一 簡介(Introduction).......................... 1
1.1 質子治療概述................................ 1
1.2 研究動機................................... 2
二 物理機制..................................... 4
2.1 帶電粒子與物質的交互作用........................4
2.1.1 帶電粒子與物質的電磁交互作用...................4
2.1.2 帶電粒子與物質的核反應....................... 6
2.2 貝特-布洛赫公式(Bethe-Bloch Formula)-阻止本領(Stopping Power) ........................................ 7
2.2.1 射程(Range).............................. 8
2.2.2 深度劑量曲線-布拉格曲線(Depth-Dose Curve - Bragg Curve) ...............................................10
2.2.3 多重庫倫散射(Multiple Coulomb Scattering，MCS) .............................................. 11
三 實驗設計及方法說明............................. 14
3.1 游離探測器(Ionization Chamber，IC)........... 14
3.1.1 氣體游離探測器基本說明....................... 14
3.1.2 氣體的游離................................. 15
3.1.3 工作電壓................................... 15
3.2 實驗用的探測器之設計........................... 17
3.3 資料擷取系統(Data Acquisition System，DAQ).... 19
3.4 探測器整體性能檢測............................. 20
3.5 實驗量測及設計................................ 21
3.5.1 實驗架設................................... 21
3.5.2 實驗步驟................................... 22
四 Geant4模擬設定及方法............................. 25
4.1 Geant4 Monte Carlo Simulation............... 25
4.1.1 幾何架構及實驗整體架設(Geometry Setup)........ 26
4.1.2 粒子與物質的交互作用(Physics List) ........... 26
4.1.3 如何開始模擬-射束源的設定
(Primary Particle Generation) .................. 29
4.1.4 得到有用的資訊、資料或數據..................... 29
4.2 質子束源的模擬設定.............................. 29
4.3 模擬的方法步驟................................. 31
五 結果與討論(Results and Discussions) ............ 34
5.1 100MeV質子束量測與模擬(100MeV Measurements and Simulations) ................................................. 35
5.1.1 能量與在水中深度劑量曲線(Beam Energy and Depth Dose Curve in Water) ....................................... 35
5.1.2 在空氣中的發散角(Dispersion Angle in Air) ..... 36
5.1.3 在水中橫向寬度變化(Lateral Width Development in Water) .................................................. 38
5.2 200 MeV質子束量測與模擬(200 MeV Measurements and Simulations) ..................................... 39
5.2.1 能量與在水中深度劑量曲線
(Beam Energy and Depth Dose Curve in Water) ...... 39
5.2.2 在空氣中的發散角(Dispersion Angle in Air) ..... 40
5.2.3 在水中橫向寬度變化(Lateral Width Development in Water) ................................................... 41
5.3 討論............................................ 42
5.3.1 深度劑量曲線(Depth Dose Curve) ................. 42
5.3.2 在水中橫向寬度變化(Lateral Width Development).... 44
六結論............................................... 46
參考文獻............................................. 47
附錄一............................................... 51
                                

[1] http://www.doh.gov.tw/CHT2006/DM/DM2_2_p02.aspx?class_no=
440&now_fod_list_no=11962&level_no=4&doc_no=81299
[2] http://www.bhp.doh.gov.tw/BHPNet/Web/News/News.aspx?No=
200712250054
[3] Thomas F. DeLaney & Hanne M. Kooy Proton and Charged Particle Radiotherapy. Lippincott Williams & Wilkins,2008
[4] Bernard Gottschalk,Lecture notes,Bloomington IN,2009
http://physics.harvard.edu/~gottschalk/
[5] B.Gottschalk, Koehler A. M., et al., "Multiple Coulomb scattering of 160 MeV protons.", Nucl. Instrum. Methods Phys. Res. B: Beam Interactions with Materials and Atoms 74(4): 467-490, (1993)
[6] V.N.Vasiliev,V.I.Kostijuchenko , et al., "Proton scattering power of some tissue-equivalent plastics",eprint arXiv:1011.4648,(2010)
http://arxiv.org/ftp/arxiv/papers/1011/1011.4648.pdf
[7] Loc Grevillot,Thibault Frisson, et al., "Optimization of GEANT4 settings for Proton Pencil Beam Scanning simulations using GATE",Nucl. Instrum. Methods Phys. Res. B: Beam Interactions withMaterials and Atoms 268(20): 3295-3305, (2010)
http://www.sciencedirect.com/science/article/pii/S0168583X10006440
[8] Schwaab, J.; Brons, S., et al., "Experimental characterization of lateral proles of scanned proton and carbon ion pencil beams for improved beam models in ion therapy treatment planning",Physics in Medicine and Biology, Volume 56, Issue 24, pp. 7813-7827 (2011).
http://iopscience.iop.org/0031-9155/56/24/7813
[9] Vandana,"OER,LET and RBE", Dept. of Radiotherapy CSMMU,
Lucknow
http://www.slideshare.net/vandana_rt/let-rbe-oer-dr-vandana
[10] Chung-Chi Lee ," Interaction of protons with matter",Lectures notes,Department of Medical Imaging and Radiological Sciences, Chang Gung University, (2012)
[11] International Commission on Radiation Units & Measurements,Reports
http://www.icru.org/link-index
[12] National Institute of Standard and Technology, Stopping-Power and Range Tables for Protons
http://physics.nist.gov/PhysRefData/Star/Text/PSTAR.html
[13] W. R. Leo Techniques for Nuclear and Particle Physics Experiments A How-to Approach. Springer-Verlag, 2d,1994
[14] Ervin. B. Podgorsak, Radiation Physics for Medical Physicists. Springer-Verlag,New York,2010
[15] E Pedroni,S Scheib,et al., "Experimental characterization and physical modelling of the dose distribution of scanned proton pencil beams",Physics in Medicine and Biology, Volume 50, Issue 3, pp.541-561 (2005). http://adsabs.harvard.edu/abs/2005PMB....50..541P
[16] Shu-Jhen Dai, "Performance Study of a Beam Monitoring System for Proton Therapy",國立中央大學,物理研究所,博碩士論文(2011).
http://ir.lib.ncu.edu.tw/handle/987654321/48240
[17] H.Bichsel,D.E Groom and S.R. Klein,"Passage of particle through matter", Particle Data Group,(2012)
http://pdg.lbl.gov/2012/reviews/rpp2012-rev-passage-particlesmatter.pdf
[18] Hans-Christian Schultz-Coulon,"Gas Detectors Large Volume Particle Tracking",Kirchho-Institut fur Physik,Universitat Heidelberg,Lecture7,(2007)
http://www.kip.uni-heidelberg.de/~coulon/Lectures/
Detectors/Free_PDFs/Lecture7.pdf
[19] Geant4,User suppot, Intoroduction to Geant4 (2007)
http://geant4.cern.ch/support/introductionToGeant4.shtml
[20] ROOT,An Object-Oriented Data Analysis Framework
http://root.cern.ch/drupal/l
[21] Roelf Slopema, "Basic Physics of Proton Therapy", University of Florida Proton Therapy Institute,(2009)
http://www.aapm.org/meetings/09PRS/documents/Slopsema.pdf
[22] 方守賢,唐靖宇, "強子治療介紹",OCPA加速器學校,(2010)
http://doc88.uquwu.com/content/201103/25/
0696ec6ecbc63745034e862ba2d1f224.html
[23] 電離輻射的生物學效應
http://www.snm.org.tw/nm-research/doctors/Concise_NM/
[24] Geant4多重庫倫散射說明
http://geant4.cern.ch/G4UsersDocuments/UsersGuides/
PhysicsReferenceManual/html/node34.html

簡易檢索 / 詳目顯示

相關論文