基于蒙特卡罗计算的伽玛刀剂量学研究
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摘要
论文以我国自行研制并已投入临床使用的LunaTM-260全身伽玛刀治疗机为对象,研究了该伽玛刀单源和多源的静态聚焦的剂量学特性。目的,建立Luna伽玛刀的蒙特卡罗剂量计算模型,模拟计算伽玛刀剂量学参数。解决Luna伽玛刀在临床使用中单源的百分深度剂量(PDD)、组织最大剂量比(TMR)、射野离轴比(OAR)及输出因子等剂量学参数无法测量的问题,并将蒙卡计算结果与治疗计划系统的数据比较,对验证伽玛刀治疗的剂量准确性进行验证。
     课题涉及伽玛刀机头的几何建模、胶片剂量计的实验测量、蒙特卡罗程序的模拟计算等工作。论文介绍并论述了目前伽玛刀计划系统的剂量计算模型及优缺点以及蒙特卡罗方法的基本原理。着重论述了Luna伽玛刀计划系统采用的TMR-OAR剂量计算模型,涉及到的一些剂量学参数,讨论了蒙特卡罗程序MCNP4C对开展本研究的可行性和实用性。详述了基于Luna伽玛刀的机头结构、材料和尺寸,以及放射源的特征的MCNP剂量计算模型的几何建模。并通过与测量数据的比较来验证计算模型的正确性,基于所建剂量计算模型开展伽玛刀单源和多源聚焦的剂量学研究。伽玛刀的实验测量采用Gafchromic EBT2新型胶片剂量计。
     研究方法:通过建立伽玛刀剂量计算模型,分别计算单源和多源射束所有准直器在30cm×30cm×30cm水模体中的剂量参数和在直径16cm的伽玛刀专用有机玻璃球模中的等剂量分布。
     结果:模拟计算了luna伽玛刀6种准直器(4mm×4mm、8mm×8mm、14mm×14mm、14mm×20mm、14mm×40mm、14mm×60mm)单源和多源的在水模中的0.5cm、5cm及10cm深度出处的百分深度剂量及离轴比;计算了在专用测量球模中的等剂量分布曲线。在水模0.5cm深度处4、5、6号准直器的射野离轴比计算结果不好;5cm和10cm处的计算结果比较理想。根据百分深度剂量与组织最大剂量比的关系,由百分深度剂量数据得到组织最大剂量比的值。将单源方模中的组织最大剂量比的计算结果、计划系统中的原始数据(测量数据)及标准的组织最大剂量比曲线进行了比较:计算结果与标准曲线符合的较好,与TPS中数据(测量)有一定误差,最大误差不超过5%。对于l号准直器在0—5cm深度范围计算值比测量值大,5—15cm深度范围计算值与测量值基本一致,大于15cm的深度计算值比测量值小;对于其余的5个准直器计算值与测量值一致,测量值大于计算值,误差为2%-5%。单源方模中5cm深度处射野离轴比的比较结果:射野内的数值符合的较好,射野外的数值相差较大。每个准直器取其焦点处的剂量作为标准值,以6号准直器最为标准归一计算了6个准直器的输出因子,将其与测量结果比较。1号准直器相差较大(大于10%),其余均小于3%。
     结论:所建立的蒙特卡罗计算模型很好地验证了单源射野的百分深度剂量(PDD)、组织最大剂量比(TMR)、射野离轴比(OAR)及输出因子,计算结果与测量结果在误差范围(5%)内符合的很好;同时,对于多源聚焦的剂量分布特点进行了研究,给出luna伽玛刀的焦点剂量分布。研究结果表明所建立的luna伽玛刀蒙特卡罗剂量计算模型可以用于其剂量学参数的验证,很好地解决了单源剂量学参数无法测量的问题,同时对于伽玛刀的临床上计划设计和剂量计算起到一定的指导性作用。本工作为伽玛刀今后研究工作奠定了基础。
The paper's object of study is the LunaTM-260whole body gamma knife treatm ent machine. Luna has developed by China and has been used in clinical.The pape r studyed the dosimetric properties of the Gamma Knife single-source and multi-so urces static focus. Purpose to setup the Gamma Knife Luna Monte Carlo dose cal culation model, and simulationly caclulate Gamma Knife dosimetry parameters. To solve the problem that the Luna Gamma Knife in the clinical use of single-source percentage depth dose (PDD), tissue maximum dose ratio (TMR), beam off-axis r atio (OAR), and dosimetric parameters such as output factors can not be measured. Compared Monte Carlo calculation resluts and treatment planning system data to verify the dose accuracy of Gamma Knife treatment for patients..
     Works involved the Gamma Knife head of geometric modeling and experimenta1measurements of film dosimeter and Monte Carlo simulation program. This paper introduces and discusses the Gamma Knife planning system for dose calculation model and their the advantage and disadvantage and the basic principle of the Mo nte Carlo method. Focus on the TMR-OAR dose calculation model use for the L una Gamma Knife planning system, and the feasibility and practicality of the Mon te Carlo code of MCNP4C for carrying out this study are discussed. Details the basic structure of the gamma knife-based Luna, the structure and size of the head section, the various parts of the material and radioactive sources, structure, shape MCNP dose calculation model of the modeling process. With the measurement dat a to verify the correctness of the calculation model, make sure built a computation al model correctly, the dosimetric parameters of the Gamma Knife single-source an d multi-source simulation and measurement data which is getted by Gafchromic E BT2new film dosimetry..
     Methods:Based on the Gamma Knife dose calculation model, I calculated dose parameters of the single-source and multi-source for all beam collimators in the30cm×30cm×30cm water phantom and the dose distribution the in the diamete r of16cm Gamma Knife dedicated plexiglass ball.
     Results:Percentage depth dose and off-axis are calculated for luna Gamma Kni fe6collimators (4mm×4mm,8mm×8mm,14mm×14mm,14mm×20mm,14mm x40mm,14mm x60mm) single-source and multi-source0.5cm,5cm an d10cm depth of the source in the water phantom and dose distribution curve in t he special ball modle. In0.5cm depth of the phantom, calculation results of the N o.4、No.5、No.6collimator of beam off-axis are not good; calculation results are g ood in5cm and10cm of the phantom. TMR(Tissue Maximum Ratio) value are c alculated from the PDD(percentage depth dose) according to the relationship betw een the PDD and the TMR. For single-source TMR calculation results, the raw da ta (measurements) in the planning system and the standard curve are compared, th e calculation results are well consistent with the standard curve, and There is a certain error between the calculation results and TPS data (measurement), which is less than5%. For the No.l collimator calculated values are more than the measur ed value from0to5cm depth in the modle, from5cm to15cm depth,the calcul ated values and measured values are basically the same, More than15cm depth,cal culated values are less than the measured values; For5the rest the collimators cal culate the values are consistent with the measured values, the measured value is g reater than the calculated value, an error is about2%-5%. In5cm depth square p hantom, beam off-axis comparison results of the Single-source:the data within the radiation field is good, but the data is not good outside the field. Each collimat or whichever is the focus at the dose as a standard value, the collimator on the N o.6most standard normalized calculated6collimator output factor and its comparis on with the measurement results. For the No.1collimator (greater than10%), and the rest were less than3%.
     Conclusion:Monte Carlo calculation model is well validated single-source beam percentage depth dose (PDD), the maximum dose ratio (TMR), the beam off-axis r atio (OAR) and output factor. Calculationthe results accord with measurement resul ts within the error range (5%) and the focus specialty of multi-source dose distrib ution was studied, the luna Gamma Knife dose distribution is presented. The result s show that the the luna Gamma Knife Monte Carlo dose calculation model can b e used for the validation of dosimetric parameters which has been founded. It ver y well soleved the problem that a single-source dosimetric parameters can not be measured.,while It can guide the Gamma Knife clinical plan design and dose calcu lation.This work laid the foundation for the Gamma Knife in the future research w ork
引文
[1]翁学军,放射治疗剂量计算的蒙特卡罗方法研究[D],东南大学博士学位论文,2003:1.
    [2]http://www.hudong.com/wiki/伽玛刀
    [3]LunaTM-260伽玛射线立体定向回转聚焦放疗机培训手册,西安一体医疗科技股份有限公司,2009:102。
    [4]胡逸民,张红志,戴建荣,肿瘤放射物理学[M],原子能出版社,1999,1版:487。
    [5]张建生,蔡勇,陈念年等MCNP程序研究进展[J].原子核物理评论,2008,25(1):48051.
    [6]林辉,吴宜灿,陈义学等.基于临床实例的影响蒙特卡罗程序MCNP计算精度和速度的若干参数模拟研究[J].原子核物理评论,2006,23(2):237-241.
    [7]林辉,宋钢,赵攀等.蒙特卡罗程序MCNP、EGSnrc、DPM剂量计算比较研究[J].中华放射医学与防护杂志,2007,27(5):473-476.
    [8]Jeraj,R,Keall,PJ,Ostwald,PM et al.Comparisons between MCNP, EGS4 and e xperiment for clinical electron beams.[J].Physics in medicine and biology,19 99,44(3):705-717.DOI:10.1299/jsmea.48.256.
    [9]雷桂媛.关于蒙特卡罗及拟蒙特卡罗方法的若干研究[D].浙江大学,2003.
    [10]王春燕,刘漪,刘云鹏等.基于Monte Carlo方法的放射治疗剂量分布计算方法的研究[J].医疗设备信息,2007,22(4):8-10.
    [11]G. Lymperopoulou,L. Petrokokkinos,P. Papagiannis et al.Monte Carlo simulati ons to optimize experimental dosimetry of narrow beams used in Gamma K nife radio-surgery [J].Nuclear Instruments & Methods in Physics Researc h. Section A, Accelerators, Spectrometers, Detectors and Associated Equipm ent,2007,580(1):548-551.
    [12]Ding, GX,Duggan, DM,Coffey, CW et al.Commissioning stereotactic radiosur gery beams using both experimental and theoretical methods[J].Physics in m edicine andbiology,2006,51 (10):2549-2566.
    [13]Cheung,JY,Yu,KN,Ho,RT et al. Monte Carlo calculated output factors of a L eksell Gamma Knife unit.[J].Physics in medicine and biology,1999,44(12):N2 47-N249.DOI:10.1111/j.1420-9101.2003.00687.x.
    [14]Moskvin V,Timmerman R,DesRosiers C et al.Monte carlo simulation of the Leksell Gamma Knife:Ⅱ. Effects of heterogeneous versus homogeneous me dia for stereotactic radiosurgery.[J].Physics in medicine and biology,2004,49 (21):4879-4895.
    [15]Papagiannis, P,Karaiskos, P,Kozicki, M et al.Three-dimensional dose verificat ion of the clinical application of gamma knife stereotactic radio surgery usin g polymer gel and MRI[J].Physics in medicine and biology,2005,50(9):1979-1990.
    [16]Vadim Moskvin,Colleen DesRosiers.Lech Papiez et al.Monte Carlo simulati on of the Leksell Gamma Knife:I. Source modelling and calculations in ho mogeneous media[J].Physics in medicine and biology,2002,47(12):1995-2011.
    [17]Li SP.,Ng KL..Monte Carlo study of the sphere packing problem[J].Physica. A, Theoretical and Statistical Physics,2003,321(1/2):359-363.
    [18]Marcelin B,Kjall P,Johansson J et al.Using Monte-Carlo-simulated radiation t ransport to calculate dose distribution in rats before irradiation with Leksell Gamma Knife 4C:technical note.[J].Stereotactic and Functional Neurosurge ry,2010,88(4):208-215.
    [19]Cheung JY,Yu KN.Study of scattered photons from the collimator system of Leksell Gamma Knife using the EGS4 Monte Carlo code.[J].Medical Physi cs,2006,33(1):41-45.DOI:10.1118/1.2143138.
    [20]Cheung JY,Yu KN.Rotating and static sources for gamma knife radiosurgery systems:Monte Carlo studies.[J].Medical Physics,2006,33(7):2500-2505.
    [21]包尚联,郭景新,黄斐增,温琛林.伽玛刀剂量的Monte cado计算[J].中国医学物理学杂志,1999,16(3)
    [22]温光浩,刘小伟,李冕丰等.伽玛刀单束射线特性的Monte Carlo模拟[J].核技术,2000,23(5):334.
    [23]李树炎,刘小伟.伽玛刀体模剂量分布的模拟研究[J].中华放射医学与防护杂志,1998,(3):199.
    [24]彭柳芬,孔令人,范善翔等Monte Carlo模拟在伽玛刀治疗中的应用[J].医疗设备信息,2006,21(1):9-11.
    [25]刘平,张一云,张晓峰.用Monte Carlo方法研究旋转γ-刀剂量分布[J].中华放射医学与防护杂志,2005,25(3):267-268.
    [26]韩俊庆,刘奇,曲凤声.伽玛刀的分代特征与选购要点.中国医疗器械杂志.2010,(34)2:117-122.
    [27]LunaTM-260伽玛射线立体定向回转聚焦放疗机技术手册,西安一体医疗科技股份有限公司,2009:102。
    [28]李大梁,王锦Luna-—一种新型的断层治疗设备(综述).未发表.
    [29]崔智.超级伽玛刀治疗计划系统研究和开发[D].浙江大学,2000.
    [30]樊军.旋转式伽玛刀治疗系统中治疗计划系统的研制[D].天津工业大学,2000.
    [31]兰海洋.精确放射治疗中剂量计算校正方法的研究[D].合肥工业大学,2009.
    [32]赵云达.基于医学图像的治疗计划软件系统的研究和开发[D].西北工业大学,20 05.
    [33]罗浩,郭吉丰,刘涵等.CT机器人伽玛刀中基于三维区域生长算法的剂量快速搜索计算研究[J].中国医疗器械杂志,2005,29(3):161-163,166.
    [34]程晓军,张从华,刘涵等.不同胶片剂量分析软件对伽玛刀验证胶片分析的结果比较[J].中华放射医学与防护杂志,2011,31(1):71-75.
    [35]陈勇,包尚联,吴昊等.胶片剂量测量和验证方法的研究[J].中华放射医学与防护杂志,2007,27(3):274-278.
    [36]Slobodan Devic. Radiochromic film dosimetry:Past, present and future. Eur opean Journal of Medical Physics.2011(27):122-134.
    [37]GAFCHROMIC(?) EBT2 SELF-DEVELOPING FILM FOR RADIOTHERAP Y DOSIMETRY. GAFCHROMIC EBT2 dosimetry film technical brief. IN TERNATIONAL SPECIALTY PRODUCTS.2009.
    [38]GAFCHROMIC(?)User Protocol Guide for IMRT QA. INTERNATIONAL SP ECIALTY PRODUCTS.2009.
    [39]程晓军,张从华,刘涵等.不同胶片剂量分析软件对伽玛刀验证胶片分析的结果比较[J].中华放射医学与防护杂志,2011,31(1):71-75.
    [40]程晓军,张从华,苏践等.胶片剂量计在γ-刀剂量学参数检测中应用及影响因素分析[J].中国职业医学,2011,38(1):33-37.
    [41]Keller,BM,Peressotti,C,Pignol,JP et al.Optical imaging analysis of microscopi c radiation dose gradients in Gafchromic EBT film using a digital microsco pe.[J].Medical Physics,2008,35(8):3740-3747.DOI:10.1118/1.2953565.
    [42]Jakob Helt-Hansen,Arne Miller.RisoScan-a new dosimetry software[J].Radiati on Physics and Chemistry,2004,71(1/2):361-364.DOI:10.1016/j.radphyschem.20 04.03.033.
    [43]EPSON Perfection V700 Photo用户手册.
    [44]User Manual VeriSoftTM Version 2.3.PTW-FREIBURG.
    [45]刘涵,郭吉丰,罗浩裴鹿成,工仲奇.蒙特卡罗方法及其应用[M].北京:海洋出版社,1999.
    [46]徐钟济.蒙特卡罗方法[M].上海:上海科学技术出版社,1985.
    [47]方再根计算机模拟与蒙特卡罗方法[M].北京:北京工业学院出版社,1998.
    [48]裴鹿成主编蒙特卡罗方法及其应用[M].长沙:国防科学技术大学出版社,1993.
    [49]许淑艳蒙特卡罗方法在实验核物理中的应用[M]北京:原子能出版社,1996.
    [50]裴鹿成,张孝泽蒙特卡罗方法及其在粒子输运过程中的应用.北京:科学出 版社,1980.
    [51]林辉,宋钢,赵攀等.蒙特卡罗程序MCNP、EGSnrc、DPM剂量计算比较研究[J].中华放射医学与防护杂志,2007,27(5):473-476.
    [52]MCNP-A General Monte Carlo N-Particle Transport Code Version 4C.
    [53]张建生,蔡勇,陈念年等MCNP程序研究进展[J].原子核物理评论,2008,25(1):48-51.
    [54]Higuchi K.,Akimoto M.,Asai K. et al.DEVELOPMENT OF MONTE CARL 0 MACHINE FOR PARTICLE TRANSPORT PROBLEM[J]. Journal of Nu clear Science andTechnology,1995,32(10):953-964.
    [55]Blair P. Bromley,Fred P. Adams,G. Bruce Wilkin et al.Development and Test ing of a MCNP-Based Method for the Analysis of Substitution Experiments [J].Transactions of the American Nuclear Society,2007,97(0):711-712.
    [56]周颖娟,黄劭敏,邓小武等.辐射显色剂量胶片的特性及其在放射医学的应用[J].国际肿瘤学杂志,2007,34(1):28-31.
    [57]孙文钊,陈立新,孙洪强等.EBT剂量胶片测量电子线百分深度剂量的应用研究[J].中华放射肿瘤学杂志,2010,19(4):331-334DOI:10.3760/cma.j.issn.1004-4221. 2010.04.016.
    [58]俞顺飞,刘立明,程金生等.使用EBT胶片测量伽玛刀放射治疗辐射场的剂量分布[J].中国医学装备,2008,5(5):27-29.
    [5.9]Fuss, M,Sturtewagen, E,De Wagter, C et al.Dosimetric characterization of G afChromic EBT film and its implication on film dosimetry quality assurance [J].Physics in medicine and biology,2007,52(14):4211-4225.
    [60]Tsang Cheung,Martin J. Butson,Peter K.N. Yu et al.ENERGY AND DOSE RESPONSE OF XRCT RADIOCHROMIC FILM[J].Australasian Physical &a mp; Engineering Sciences in Medicine,2007,30(4):440-440.
    [61]陈勇,包尚联,吴昊等.胶片剂量测量和验证方法的研究[J].中华放射医学与防护杂志,2007,27(3):274-278.
    [62]王顺官,洪文松,蔡长青等.胶片剂量分析系统及其在放疗验证中的应用[J].南方医科大学学报,2006,26(7):1039-1040.
    [63]奚越.基于胶片的放射治疗剂量分析系统[D].山东大学,2004.
    [64]Su, FC,Shi, CY,Papanikolaou, N et al.Clinical application of GAFCHROMI C (R) EBT film for in vivo dose measurements of total body irradiation ra diotherapy[J].Applied Radiation and Isotopes,2008,66(3):389-394.
    [65]Cheng-fa He,M. Geso,T. Ackerly et al.Stereotactic dose perturbation from an aneurysm clip measured by Gafchromic-R EBT film[J].Australasian Physica 1 Lamp; Engineering Sciences in Medicine.2008,31(1):18-23.
    [66]Butson, M.J.,Yu, P.K.N.,Cheung, T. et al.Energy response of the new EBT2 Radiochromic film to X-ray radiation[J].Radiation measurements,2010,45(7): 836-839.
    [67]刘涵.基于CT机器人伽玛刀剂量场分析及验证系统[D].浙江大学,2005.
    [68]周金斌.基于Monte Carlo模拟的矩阵模型fsPB算法研究[D].合肥工业大学,2008.
    [69]周凌宏,金浩宇,陈超敏等.基于蒙特卡罗模拟的快速剂量计算方法研究[J].仪器仪表学报,2007,28(4):699-702.
    [70]陈朝斌,黄群英,吴宜灿等.蒙特卡罗方法在放疗计划中的应用[J].核技术,2006,29(1):22-28.
    [71]金浩宇,周凌宏,陈光杰等.一种基于蒙特卡罗模拟的快速剂量计算模型[J].第四军医大学学报,2006,27(21):2002-2004.
    [72]吴爱东,吴宜灿.CT图像的体元大小对EGSnrc蒙特卡罗剂量计算的影响[J].核技术,2007,30(2):143-146.
    [73]马永忠,于时进,苏旭等.立体定向放射治疗中靶外剂量分布的研究[J].中国职业医学,2006,33(2):94-97.
    [74]刘宗良,李强,赵平华等.蒙特卡罗方法及其在辐射剂量计算中的应用[J].湖南人文科技学院学报,2006,(6):19-22.
    [75]尹增谦,管景峰,张晓宏等.蒙特卡罗方法及应用[J].物理与工程,2002,12(3):45-49.
    [76]王茵,彭柳芬,黄文建等.伽玛刀治疗方案模型[J].暨南大学学报(自然科学与医学版),2003,24(5):47-53.
    [77]Cheung JY,Yu KN,Yu CP et al.Choice of phantom materials for dosimetry o f Leksell Gamma Knife unit:a Monte Carlo study.[J].Medical Physics,2002, 29(10):2260-2261.DOI:10.1118/1.1508797.
    [78]Guerrero M,Li XA,Ma L et al.A technique to sharpen the beam penumbra f or Gamma Knife radio surgery. [J]. Physics in medicine and biology,2003,48(1 2):1843-1853.DOI:10.1088/0031-9155/48/12/312.
    [79]Ma,L,Li,XA,Yu,CX et al.An efficient method of measuring the 4 mm helme t output factor for the Gamma knife.[J].Physics in medicine and biology,200 0,45(3):729-733.DOI:10.1088/0031-9155/45/3/311.
    [80]A-Dweri, Feras M. O.,Lallena, Antonio M.,Vilches, Manuel等.A simplified model of the source channel of the Leksell GammaKnife tested with PENE LOPE[J].2004,.DOI:"".
    [81]Abella V,Miro R,Juste B et al.3D dose distribution calculation in a voxelize d human phantom by means of Monte Carlo method.[J].Applied radiation a nd isotopes,2010,68(4/5):709-713.
    [82]W Xiong, D Huang, L Lee, J Feng, K Morris, E Calugaru, C Burman, J L i and C-M Ma,Implementation of Monte Carlo Simulations for the Gamma, Knife System, Journal of Physics:Conference Series 74 (2007) 012023:1-8.
    [83]刘艳梅,薛定宇,徐心和等.放射治疗剂量分布的计算机模拟[J].计算机工程与应用,2005,41(36):12-15,71.
    [84]林辉,吴宜灿,陈义学等.基于临床实例的影响蒙特卡罗程序MCNP计算精度和速度的若干参数模拟研究[J].原子核物理评论,2006,23(2):237-241.
    [85]丰树强,刘保杰,程金生等.60Co远程治疗机剂量场分布的Monte Carlo计算[J].清华大学学报(自然科学版),2007,47(z1):914-916.
    [1]韩俊庆,刘奇,曲凤声等.伽玛刀的分代特征与选购要点[J].中国医疗器械杂志,2010,34(2):117-122.
    [2]周正东,罗立民,舒华忠等.放射治疗计划的优化方法[J].中国医疗器械杂志,2007,31(6):391-394,444.
    [3]岁光华,王宇田.立体定向放射外科的新发展-旋转式伽玛刀[J].海南医学,2005,16(5):110-112.
    [4]张卫军,戴嘉中,蔡佩武等.伽玛刀放射外科进展[J].医学综述,2001,7(5):315-317.
    [5]王晓光,刘群,王平等.放射外科的发展(从头架到影像引导)[J].中国肿瘤临床,2008,35(13):770-774.
    [6]Luan,S,Swanson,N,Chen,Z et al.Dynamic gamma knife radiosurgery.[J].Physics i n medicine and biology,2009,54(6):1579-1591.
    [7]Ma L,Kjall P,Novotny J et al.A simple and effective method for validation an d measurement of collimator output factors for Leksell Gamma Knife Perfexio n.[J].Physics in medicine and biology,2009,54(12):3897-3907.
    [8]Karaiskos, P,Petrokokkinos, L,Tatsis, E et al.Dose verification of single shot ga mma knife applications using VIPAR polymer gel and MRI[J].Physics in medi cine and biology,2005,50(6):1235-1250.

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