Monte Carlo estimation of electron contamination in a 18 MV clinical photon beam

نویسندگان

  • A. Mesbahi
  • H. Alijanzadeh
  • M. Allahverdi
  • M. Shahriari
  • M. Zabihzadeh
  • S.R. Mahdavi
چکیده مقاله:

Background: The electron contamination may reduce or even diminish the skin sparing property of the megavoltage beam. The detailed characteristics of contaminant electrons are presented for different field sizes and cases. Materials and Methods: The Monte Carlo code, MCNPX, has been used to simulate 18 MV photon beam from a Varian Linac-2300 accelerator. All dose measurements were carried out using a PTW-MP2 scanner with an ionization chamber (0.6 CC) at the water phantom. Results: The maximum electron contaminant dose at the surface ranged from 6.1 % for 5 × 5 cm2 to 38.8 % for 40 × 40 cm2 and at the depth of maximum dose was 0.9 % up to 5.77 % for the 5 × 5 cm2 to the 40 × 40 cm2 field sizes, respectively. The additional contaminant electron dose at the surface for the field with tray increased 2.3 % for 10 × 10 cm2, 7.3 % for 20 × 20 cm2, and 21.4 % for 40 × 40 cm2 field size comparing to the standard field without any accessories. This increase for field with tray and shaping block was 5.3 % and 13.3 % for 10 × 10 and 20 × 20 cm2, respectively, while, the electron contamination decreased for the fields with wedge, i.e. 2.2 % for the 10 × 10 cm2 field. Conclusion: The results have provided more comprehensive knowledge of the high-energy clinical beams and may be useful to develop the accurate treatment planning systems capable of taking the electron contamination in to account. Iran. J. Radiat. Res., 2011 9(1): 15-28

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

monte carlo estimation of electron contamination in a 18 mv clinical photon beam

background: the electron contamination may reduce or even diminish the skin sparing property of the megavoltage beam. the detailed characteristics of contaminant electrons are presented for different field sizes and cases. materials and methods: the monte carlo code, mcnpx, has been used to simulate 18 mv photon beam from a varian linac-2300 accelerator. all dose measurements were carried out u...

متن کامل

Evaluation of Electron Contamination in Cancer Treatment with Megavoltage Photon Beams: Monte Carlo Study

Background: Megavoltage beams used in radiotherapy are contaminated with secondary electrons. Different parts of linac head and air above patient act as a source of this contamination. This contamination can increase damage to skin and subcutaneous tissue during radiotherapy. Monte Carlo simulation is an accurate method for dose calculation in medical dosimetry and has an important role in opt...

متن کامل

Monte carlo simulation of varian clinac iX 10 MV photon beam for small field dosimetry

Background: The lack of lateral electronic disequilibrium (LED) becomes a main problem in small field. This factor affects the dose in target volume cannot predict correctly. In addition, utilization of high-energy linear accelerator (10 MV) can emit some unwanted particles (electron contamination). Therefore, the aim of this study was to characterize head linear accelerator (linac) Varian Clin...

متن کامل

Measurements of Photon Beam Flattening Filter Using an Anisotropic Analytical Algorithm and Electron Beam Employing Electron Monte Carlo

  Introduction: This study aimed to report the measurement of photon and electron beams to configure the Analytical Anisotropic Algorithm and Electron Monte Carlo used in clinical treatment. Material and Methods: All measurements were performed in a large water phantom using a 3-dimensional scanning system (PTW, Germany). ...

متن کامل

Benchmarking of Monte Carlo model of 6 Mv photon beam produced by Siemens Oncor® linear accelerator: determination of initial electron beam parameters in comparison with measurement

Introduction: The aim of this study was to investigate the initial electron beam parameters for Monte Carlo model of 6MV photon beam produced by Siemens Oncor® linear accelerator.   Materials and Methods: In this study, the EGSnrc Monte Carlo user codes BEAMnrc and DOSXYZnrc were used. The beamnrc code were used for modelling of a 6 MV photon beam produced by...

متن کامل

Monte Carlo Simulation of Siemens Primus plus Linac for 6 and 18 MV Photon Beams

Objective: The aim of the present study is to simulate 6 MV and 18 MV photon beam energies of a Siemens Primus Plus medical linear accelerator (Linac) and to verify the simulation by comparing the results with the measured data.Methods: The main components of the head of Siemens Primus Plus linac were simulated using MCNPX Monte Carlo (MC) code. To verify the results, experimental data of perce...

متن کامل

منابع من

با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ذخیره در منابع من قبلا به منابع من ذحیره شده

{@ msg_add @}


عنوان ژورنال

دوره 9  شماره None

صفحات  15- 28

تاریخ انتشار 2011-06

با دنبال کردن یک ژورنال هنگامی که شماره جدید این ژورنال منتشر می شود به شما از طریق ایمیل اطلاع داده می شود.

کلمات کلیدی

میزبانی شده توسط پلتفرم ابری doprax.com

copyright © 2015-2023