【摘 要】
:
Purpose:This study was to evaluate the setup accuracy of intensity modulated radiation therapy(IMRT)of ten patients with lung cancer by cone-beam computed tomography(CBCT)in Elekta Synergy S Linear Ac
【机 构】
:
Department of Nuclear Science & Engineering,Nanjing University of Aeronautics and Astronautics,Nanji
【出 处】
:
The 15th Asia-Oceania Congress of Medical Physics (AOCMP2015
论文部分内容阅读
Purpose:This study was to evaluate the setup accuracy of intensity modulated radiation therapy(IMRT)of ten patients with lung cancer by cone-beam computed tomography(CBCT)in Elekta Synergy S Linear Accelerator,to obtain and analyze the clinical setup errors of radiotherapy,and to investigate the margins of clinical target volume(CTV)based on the setup errors.Methods:The image-guided radiotherapy(IGRT)was conducted for ten patients with lung cancer chosen randomly each day,and the clinical registration between CBCT images and treatment planning CT images was carried out to keep the actual irradiation isocenter consistent with the treatment planning isocenter.The translational errors in right-left(x),superior-interferior(y),anterior-posterior(z)directions and the rotational errors in u,υ,w directions formed by x,y,z directions were calculated and analyzed for each patient in the whole course of treatment each day,and the margins of CTV were got according to M=2.5Σ+0.7δ equation on the basis of setup errors.Results:The tumors of patients and the surrounding soft tissue structures can be shown in the CBCT images more clearly,and the setup errors in translation on x,y and z axes were(0.05±0.16)cm,(0.09±0.32)cm and(-0.02±0.13)cm,respectively,while the setup errors in rotation in u,υ,w directions were(0.41±0.64)°,(-0.08±0.57)°and(-0.03±0.62)°,respectively.Based on the setup errors of patients,the margins of CTV for lung cancer were 0.82cm,1.15cm and 0.72cm,respectively.Conclusion:A certain setup errors occurred in IGRT for patients with lung cancer,and it was more obvious in superior-interferior direction.However,CBCT is capable of measuring and online correcting the setup errors,significantly reducing the setup errors of lung cancer,and enhancing the accuracy of radiotherapy,it also can evaluate the margin value and better protect the organs at risk(OARs)and normal tissues.
其他文献
Purpose:To develop a pencil beam algorithm(PBA)for dose calculation of proton beams in both homogeneous and heterogeneous media.Methods:The proton PBA consisted of the integral depth-dose and the off-
Purpose:In IMRT QA,plan quality evaluation is made based on pass rate under preset acceptance criteria,mostly using gamma-values.This method is convenient but,its result highly depends on what the acc
Purpose In IMRT QA,the geometric errors(GE),which differences between the reference and measured dose distribution caused by a rotation and shift of a dose distribution because of QA environment setti
TOPAS is a newly developed Monte Carlo simulation tool that combines extensive radiation physics libraries available in Geant4 code and easy-to-use geometry and visualization features.Although TOPAS h
The single source channel of Leksell Gamma Knife was simulated using Monte Carlo N-Particle Transport Code System(MCNPX version).The accurate dose distribution in a water-equivalent sphere phantom of
Medical Physics research contributions have been dominated by development of conformal treatment delivery technologies along with planning,imaging,and dose prediction tools that support accurate deliv
Purpose The 3-D reconstruction of the fluorescence yield is achieved by using a method that main interest is its ability to reconstruct the fluorescence distribution in media presenting heterogeneous
Purpose:To systematically evaluate accumulative imaging doses to organs-at-risk and associated lifetime attributable risk(LAR)of cancer incidence caused by various radiological imaging procedures perf
Introduction:We have developing a collision-detection simulator between treatment units and a patient for dynamic wave arc(DWA)irradiation achieving dose delivery to a target by continuous ring and ga
Objective:To analyze three different kinds of finger shape ionization chamber of medical linear accelerator is used the response of the dose rate.Methods:Choose three different kinds of finger shape i