超級(jí)蒙卡核模擬軟件系統(tǒng)SuperMC在近距離放療和硼中子俘獲治療中的測(cè)試和應(yīng)用.pdf

1、The goal of radiotherapy is to cure cancer tumors through ionizing radiation whilesaving the surrounding healthy tissues.These treatments require an accurate determination of all those dosimetric parameters, which are re

2、quired for treatment planning system(TPS).Many TPS in clinical use perform dose calculation by analytical method whichis not accurate in inhomogeneous medium.Alternatively, the Monte Carlo (MC) particle transport codes h

3、ave been recognized as the most accurate method for radiotherapytreatment planning and dose calculation.Before calculating the dosimetric parametersthrough MC methods, it is important to test MC transport code for radiot

4、herapy.Testingmust be done with benchmark cases from IAEA (International Atomic Energy Agency),AAPM (American Association of Physicists in Medicine), experimental measurementsand/or other validated Monte Carlo codes.

5、　　In this work, SuperMC (Super Monte Carlo Program for Nuclear and RadiationSimulation) has been tested and validated for medical physics applications such asbrachytherapy and boron neutron capture therapy (BNCT).Brachyt

6、herapy is a formof radiotherapy in which a sealed radiation source is placed inside or next to the area requiring treatment while BNCT is a noninvasive therapeutic modality for treating locallyinvasive malignant tumors s

7、uch as primary brain tumors and recurrent head and neckcancer.Investigations for coupled modeling and simulation of brachytherapy sourcewith water phantom and BNCT treatment head with computational human phantomhave been

8、 carried out.The main and innovative research contents of this dissertationare briefly described below:
　　(1)In this study, SuperMC has been tested and verified for high dose rate (HDR)brachythrapy source.Cylindrical

9、geometry based brachytherapy source was modeledwith SuperMC and dose calculations were carried out with the source placed at thecenter of spherical water phantom.The verification has been done by calculating thedosimetri

10、c parameters as recommended by AAPM in task group report 43 and 43U1(TG-43, TG-43U1) and by comparing these parameters with studies from other MonteCarlo codes such as EGSnrc, PENELOPE, MCTP, MCNP and published experimen

11、taldata.It has been found that calculated parameters are in good agreement with publishedMonte Carlo studies and experimental data.The results show that SuperMC can beused foraccurate and fast simulation and dosimetric c

12、alculation of HDR brachytherapysources.
　　(2)In this study, SuperMC has been applied to boron neutron capture therapy.Forthis purpose, a beam shaping assembly (BSA) has been designed to moderate mono energetic high en

13、ergy (14.1 MeV) neutron beam to epithermal energy range for the treatment of deep seated head and neck tumors.The BSA consists of moderator, reflector,filter, gamma shield and collimator.CT images of the patient' s head

14、were converted to geometry model of SuperMC.The verification of the beam quality was done bycomparing the dosimetric parameters as recommended by IAEA-TECDOC1223 andcomputational head phantom results were compared previo

15、us studies.In air and inphantom results are in good agreement with IAEA and previous studies.Dose analysisshowsthat the designed BSA is accurate, efficient and suitable for BNCT applicationsand SuperMC can be used for si

16、mulating BSA and dose calculations for BNCT.
　　Testing and verifications has been done with benchmark cases from IAEA andAAPM to verify and validate the performance of SuperMC for radiotherapy and its applications.Sup

17、erMC has also been applied for treatment planning of clinical cases.Theobtained results with SuperMC are in very good agreement with results of benchmarkcases.SuperMC was found to be accurate, efficient and capable for d

18、ose calculationand treatment planning.It is concluded that SuperMC can be used for the accurate modeling and simulation ofdosimetric parameters in water and in heterogeneous phantomsand Monte Carlo based treatment planni