کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1882427 1533529 2014 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Determining optimization of the initial parameters in Monte Carlo simulation for linear accelerator radiotherapy
ترجمه فارسی عنوان
تعیین بهینه سازی پارامترهای اولیه در شبیه سازی مونت کارلو برای پرتودرمانی شتاب دهنده خطی
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم تشعشع
چکیده انگلیسی

Monte Carlo (MC) method is a well known calculation algorithm which can accurately assess the dose distribution for radiotherapy. The present study investigated all the possible regions of the depth-dose or lateral profiles which may affect the fitting of the initial parameters (mean energy and the radial intensity (full width at half maximum, FWHM) of the incident electron). EGSnrc-based BEAMnrc codes were used to generate the phase space files (SSD=100 cm, FS=40×40 cm2) for the linac (linear accelerator, Varian 21EX, 6 MV photon mode) and EGSnrc-based DOSXYZnrc code was used to calculate the dose in the region of interest. Interpolation of depth dose curves of pre-set energies was proposed as a preliminary step for optimal energy fit. A good approach for determination of the optimal mean energy is the difference comparison of the PDD curves excluding buildup region, and using D(10) as a normalization method. For FWHM fitting, due to electron disequilibrium and the larger statistical uncertainty, using horn or/and penumbra regions will give inconsistent outcomes at various depths. Difference comparisons should be performed in the flat regions of the off-axis dose profiles at various depths to optimize the FWHM parameter.


► Crucial parameters were investigated using a logical system procedure.
► Interpolation of depth dose curves using pre-set energies as a first step.
► Comparisons using PDD curves normalized by D(10), excluding buildup region.
► FWHM is sensitive to horn/penumbra regions, but they give inconsistent values.
► Optimizing the FWHM requires the flat regions at various depths.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Radiation Physics and Chemistry - Volume 95, February 2014, Pages 161–165
نویسندگان
, , ,