跳到主要內容

簡易檢索 / 詳目顯示

研究生: 汎妮莎
Vanny Maranatha Sihotang
論文名稱: 正電子發射極和瞬變伽馬的模擬 質子範圍驗證的分佈 使用PTSim進行治療
Simulation of Positron Emitter and Prompt Gamma Distributions for Range Verification in Proton Therapy by Using PTSim
指導教授: 陳鎰鋒
Augustine 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: 2020
畢業學年度: 109
語文別: 英文
論文頁數: 63
中文關鍵詞: 質子治療PTSim
外文關鍵詞: Proton Therapy, PTSim
相關次數: 點閱:23下載:0
分享至:
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
  • 與光子療法相比,質子束能向目標提供更好的劑量分佈,同時將目標周圍的正常組織的劑 量最小化,在遠端邊緣以外的劑量沉積非常低,盡可能地降低對正常組織的損害。但是,質子射束在射程終點有較大的劑量梯度,這可能造成治療時的劑量分布不確定性。因此,需要在治療計劃中盡可能準確地預測質子束在人體中的劑量分佈,並在治療過程中對其進行良好的監控,例如透過檢測二次粒子來進行體內治療監測。通過質子與目標原子核(例
    如 12C,14N 和 16O)的非彈性碰撞核反應,可能產生正子核種,或由被激發靶原子核發出瞬發伽馬射線。從患者體內發出的這些正子核種和瞬發伽馬射線與質子劑量空間分佈具有相關性。本研究採用基於 Geant4 10.4.p02 的 PTSim 套件進行碳,水,PE 和 PMMA 的相關研究,並利用林口長庚醫院質子治療中心真實治療機台的輻射相空間數據為射源,評估不同能量質子造成的正子核種及瞬發伽馬分佈,以驗證質子射程。本研究中偵測的伽馬能譜範圍是 0 – 10 MeV。並發現正子核種、瞬發伽馬及質子劑量三者分布有良好的相關性。瞬發伽馬和質子射程之間的差異為 1.5 – 3.3 mm,正子核種與質子射程之間的差異為 7.2 – 10.5
    mm。此外,本研究模擬的正子核種分布與在長庚醫院測得由 130 MeV 質子照射 PMMA所得的互毀光子信號具有一致性。同時,本研究認為 PTSim用於模擬組織中的核相互作用
    和正子核種分布上是一種功能強大且合適的工具。


    Proton beam offers a better dose distribution to the target while minimizing the dose to the normal tissue surrounding the target, as the dose deposited beyond the distal edge is
    very low and the damage to the normal tissue will be minimized in comparison with the photon therapy. However, the end of range is where the beam features its sharpest dose
    gradient could be the uncertainties that are encountered in a patient. Therefore, the dose distribution of protons beam in the human body needs to be predicted as accurate as
    possible in the treatment planning and well monitored in the delivery process. In vivo treatment monitoring can be performed by detecting the secondary particles. Through the
    non-elastic nuclear interaction of protons with the target nuclei such as 12C, 14N, and 16O will produce positron emitters and prompt gammas. These positron emitters and prompt gammas rays emitted from the patient body are strongly associated with the dose distribution of the proton beam. In this thesis, simulations of carbon, water, PE, and
    PMMA irradiated with phase space data-carrying CGMH proton beam characteristics are studied. The PTSim based on Geant4 10.4 patch 2 was applied for those various targets to
    evaluate the positron emitter and prompt gamma distributions from different proton energies to verify the proton range. To validate our simulation system we compare the depth dose distribution from simulation with the measurement at CGMH under the same condition. The gamma energies detected in this study were in the range of 0 – 10 MeV. There is a good relation between positron emitter and prompt gamma distribution with the dose distribution. Differences between ranges of prompt gamma and proton are 1.5 –3.3 mm and positron emitter with proton are 7.2 – 10.5 mm. The range verification by comparing the measurement data of coincidence 511 keV gammas obtained at CGMH and simulation result of positron emitter distributions in PMMA by 130 MeV protons shows the good agreement. Also, PTSim is a powerful and suitable tool for the simulation of nuclear interactions and positron emitters in tissue.

    ABSTRACT.................................................................................................................... i ABSTRACT 摘要.......................................................................................................... ii Acknowledgements ....................................................................................................... iii Table of Contents .......................................................................................................... iv List of Figures ............................................................................................................... vi List of Tables................................................................................................................. ix Chapter 1 - Introduction...................................................................................................1 1.1. Proton Therapy..................................................................................................1 1.2. Introduction of Positron Annihilation Gamma (PAG) ........................................4 1.3. Introduction of Prompt Gamma (PG).................................................................4 1.4. Proton Therapy in Chang Gung Memorial Hospital Taiwan...............................4 1.5. Objectives and Aims..........................................................................................5 1.6. Thesis Structure Overview.................................................................................5 Chapter 2 - Theory...........................................................................................................6 2.1 Proton Interaction with Matter...........................................................................6 2.1.1 Stopping Power..............................................................................................7 2.1.2 Multiple Coulomb Scattering .........................................................................7 2.1.3 Nuclear Interactions.......................................................................................8 2.2 Proton Bragg Peak.............................................................................................9 2.3 Secondary Gamma during Proton Therapy ......................................................10 v 2.3.1 Positron Annihilation Gamma (PAG) .......................................................10 2.3.2 Prompt Gamma (PG)................................................................................12 2.4 Range uncertainties in Proton Therapy ............................................................14 2.5 In vivo Dose Monitoring ..................................................................................16 2.5.1 Direct Methods.........................................................................................16 2.5.2 Indirect Methods ......................................................................................17 Chapter 3 – Material and Method...................................................................................19 3.1 Geometry And Tracking 4 (GEANT4).............................................................19 3.2 Particle Therapy System Simulation (PTSim) ..................................................20 3.3 Phase Space (PHSP) file ..................................................................................21 3.4 PTSim Monte Carlo Simulation Setup .............................................................22 3.5 Research Workflow .........................................................................................24 3.6 Experimental Setup at Chang Gung Memorial Hospital (CGMH)....................25 Chapter 4 – Results and Discussion ...............................................................................27 4.1 Depth Dose Distribution ..................................................................................27 4.2 Gamma Spectrum from different targets and proton energies...........................28 4.3 The PAG, PG and Dose Distributions..............................................................34 4.4 Experimental Verification of Range.................................................................41 Chapter 5 - Conclusions.................................................................................................44 Bibliographies ...............................................................................................................46

    Bibliographies
    Agostinelli, S. et al. (2003). Geant4—a simulation toolkit. Nuclear Instruments and
    Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors,
    and Associated Equipment, 506(3), 250-303. doi:10.1016/s0168-9002(03)01368-8
    Akagi, T. et al. (2011). The PTSim and TOPAS Projects, Bringing Geant4 to the Particle
    Therapy Clinic. Progress in Nuclear Science and Technology, 2(0), 912-917.
    doi:10.15669/pnst.2.912
    Baskar, R. et al. (2012). Cancer and radiation therapy: current advances and future
    directions. Int J Med Sci, 9(3), 193-199. doi:10.7150/ijms.3635
    Cai, S. Y. et al. (2015). Depth dose characteristics of proton beams within therapeutic
    energy range using the particle therapy simulation framework (PTSim) Monte
    Carlo technique. Biomed J, 38(5), 408-413. doi:10.4103/2319-4170.167076
    Hueso-Gonzalez. et al. (2016). Compton Camera and Prompt Gamma Ray Timing: Two
    Methods for In Vivo Range Assessment in Proton Therapy. Front Oncol, 6, 80.
    doi:10.3389/fonc.2016.00080
    Knopf, A. C., & Lomax, A. (2013). In vivo proton range verification: a review. Phys Med
    Biol, 58(15), R131-160. doi:10.1088/0031-9155/58/15/R131
    Kraan, A. C. (2015). Range Verification Methods in Particle Therapy: Underlying
    Physics and Monte Carlo Modeling. Front Oncol, 5, 150.
    doi:10.3389/fonc.2015.00150
    Lau, A. et al. (2013). Range verification of proton radiotherapy with prompt gamma rays.
    J Xray Sci Technol, 21(4), 507-514. doi:10.3233/XST-130399
    Mashayekhi, M. et al. (2017). Simulation of positron emitters for monitoring of dose
    distribution in proton therapy. Rep Pract Oncol Radiother, 22(1), 52-57.
    doi:10.1016/j.rpor.2016.10.004
    Miyatake, A. et al. (2010). Measurement and verification of positron emitter nuclei
    generated at each treatment site by target nuclear fragment reactions in proton
    therapy. Med Phys, 37(8), 4445-4455. doi:10.1118/1.3462559
    47
    Newhauser, W. D., & Zhang, R. (2015). The physics of proton therapy. Phys Med Biol,
    60(8), R155-209. doi:10.1088/0031-9155/60/8/R155
    Paganetti, H. (2012). Range uncertainties in proton therapy and the role of Monte Carlo
    simulations. Phys Med Biol, 57(11), R99-117. doi:10.1088/0031-9155/57/11/R99
    Parodi, K. et al. (2007). Patient study of in vivo verification of beam delivery and range,
    using positron emission tomography and computed tomography imaging after
    proton therapy. Int J Radiat Oncol Biol Phys, 68(3), 920-934.
    doi:10.1016/j.ijrobp.2007.01.063
    Polf, J. C. et al. (2014). Detecting prompt gamma emission during proton therapy: the
    effects of detector size and distance from the patient. Phys Med Biol, 59(9), 2325-
    2340. doi:10.1088/0031-9155/59/9/2325
    Polf, J. C. et al. (2013). Measurement of characteristic prompt gamma rays emitted from
    oxygen and carbon in tissue-equivalent samples during proton beam irradiation.
    Phys Med Biol, 58(17), 5821-5831. doi:10.1088/0031-9155/58/17/5821
    Robert, C. et al. (2013). PET-based dose delivery verification in proton therapy: a GATE
    based simulation study of five PET system designs in clinical conditions. Phys
    Med Biol, 58(19), 6867-6885. doi:10.1088/0031-9155/58/19/6867
    Schneider, S. et al. (2018). Quantification of MRI visibility and artifacts at 3T of liquid
    fiducial marker in a pancreas tissue-mimicking phantom. Med Phys, 45(1), 37-47.
    doi:10.1002/mp.12670
    Verburg, J. M., & Seco, J. (2014). Proton range verification through prompt gamma-ray
    spectroscopy. Phys Med Biol, 59(23), 7089-7106. doi:10.1088/0031-
    9155/59/23/7089
    Wrońska, A. et al. (2017). Experimental Verification of Key Cross Sections for Promptgamma Imaging in Proton Therapy. Acta Physica Polonica B, 48(10).
    doi:10.5506/APhysPolB.48.1631

    QR CODE
    :::