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Validation of total skin electron irradiation (TSEI) technique dosimetry data by Monte Carlo simulation

Total skin electron irradiation (TSEI) is a complex technique which requires many nonstandard measurements and dosimetric procedures. The purpose of this work was to validate measured dosimetry data by Monte Carlo (MC) simulations using EGSnrc‐based codes (BEAMnrc and DOSXYZnrc). Our MC simulations...

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Autores principales: Nevelsky, Alexander, Borzov, Egor, Daniel, Shahar, Bar‐Deroma, Raquel
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5690047/
https://www.ncbi.nlm.nih.gov/pubmed/27455502
http://dx.doi.org/10.1120/jacmp.v17i4.6230
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author Nevelsky, Alexander
Borzov, Egor
Daniel, Shahar
Bar‐Deroma, Raquel
author_facet Nevelsky, Alexander
Borzov, Egor
Daniel, Shahar
Bar‐Deroma, Raquel
author_sort Nevelsky, Alexander
collection PubMed
description Total skin electron irradiation (TSEI) is a complex technique which requires many nonstandard measurements and dosimetric procedures. The purpose of this work was to validate measured dosimetry data by Monte Carlo (MC) simulations using EGSnrc‐based codes (BEAMnrc and DOSXYZnrc). Our MC simulations consisted of two major steps. In the first step, the incident electron beam parameters (energy spectrum, FWHM, mean angular spread) were adjusted to match the measured data (PDD and profile) at [Formula: see text] for an open field. In the second step, these parameters were used to calculate dose distributions at the treatment distance of 400 cm. MC simulations of dose distributions from single and dual fields at the treatment distance were performed in a water phantom. Dose distribution from the full treatment with six dual fields was simulated in a CT‐based anthropomorphic phantom. MC calculations were compared to the available set of measurements used in clinical practice. For one direct field, MC calculated PDDs agreed within 3%/1 mm with the measurements, and lateral profiles agreed within 3% with the measured data. For the OF, the measured and calculated results were within 2% agreement. The optimal angle of 17° was confirmed for the dual field setup. Dose distribution from the full treatment with six dual fields was simulated in a CT‐based anthropomorphic phantom. The MC‐calculated multiplication factor (B12‐factor), which relates the skin dose for the whole treatment to the dose from one calibration field, for setups with and without degrader was 2.9 and 2.8, respectively. The measured B12‐factor was 2.8 for both setups. The difference between calculated and measured values was within 3.5%. It was found that a degrader provides more homogeneous dose distribution. The measured X‐ray contamination for the full treatment was 0.4%; this is compared to the 0.5% X‐ray contamination obtained with the MC calculation. Feasibility of MC simulation in an anthropomorphic phantom for a full TSEI treatment was proved and is reported for the first time in the literature. The results of our MC calculations were found to be in general agreement with the measurements, providing a promising tool for further studies of dose distribution calculations in TSEI. PACS number(s): 87.10. Rt, 87.55.K, 87.55.ne
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spelling pubmed-56900472018-04-02 Validation of total skin electron irradiation (TSEI) technique dosimetry data by Monte Carlo simulation Nevelsky, Alexander Borzov, Egor Daniel, Shahar Bar‐Deroma, Raquel J Appl Clin Med Phys Radiation Measurements Total skin electron irradiation (TSEI) is a complex technique which requires many nonstandard measurements and dosimetric procedures. The purpose of this work was to validate measured dosimetry data by Monte Carlo (MC) simulations using EGSnrc‐based codes (BEAMnrc and DOSXYZnrc). Our MC simulations consisted of two major steps. In the first step, the incident electron beam parameters (energy spectrum, FWHM, mean angular spread) were adjusted to match the measured data (PDD and profile) at [Formula: see text] for an open field. In the second step, these parameters were used to calculate dose distributions at the treatment distance of 400 cm. MC simulations of dose distributions from single and dual fields at the treatment distance were performed in a water phantom. Dose distribution from the full treatment with six dual fields was simulated in a CT‐based anthropomorphic phantom. MC calculations were compared to the available set of measurements used in clinical practice. For one direct field, MC calculated PDDs agreed within 3%/1 mm with the measurements, and lateral profiles agreed within 3% with the measured data. For the OF, the measured and calculated results were within 2% agreement. The optimal angle of 17° was confirmed for the dual field setup. Dose distribution from the full treatment with six dual fields was simulated in a CT‐based anthropomorphic phantom. The MC‐calculated multiplication factor (B12‐factor), which relates the skin dose for the whole treatment to the dose from one calibration field, for setups with and without degrader was 2.9 and 2.8, respectively. The measured B12‐factor was 2.8 for both setups. The difference between calculated and measured values was within 3.5%. It was found that a degrader provides more homogeneous dose distribution. The measured X‐ray contamination for the full treatment was 0.4%; this is compared to the 0.5% X‐ray contamination obtained with the MC calculation. Feasibility of MC simulation in an anthropomorphic phantom for a full TSEI treatment was proved and is reported for the first time in the literature. The results of our MC calculations were found to be in general agreement with the measurements, providing a promising tool for further studies of dose distribution calculations in TSEI. PACS number(s): 87.10. Rt, 87.55.K, 87.55.ne John Wiley and Sons Inc. 2016-07-08 /pmc/articles/PMC5690047/ /pubmed/27455502 http://dx.doi.org/10.1120/jacmp.v17i4.6230 Text en © 2016 The Authors. This is an open access article under the terms of the Creative Commons Attribution (http://creativecommons.org/licenses/by/3.0/) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
spellingShingle Radiation Measurements
Nevelsky, Alexander
Borzov, Egor
Daniel, Shahar
Bar‐Deroma, Raquel
Validation of total skin electron irradiation (TSEI) technique dosimetry data by Monte Carlo simulation
title Validation of total skin electron irradiation (TSEI) technique dosimetry data by Monte Carlo simulation
title_full Validation of total skin electron irradiation (TSEI) technique dosimetry data by Monte Carlo simulation
title_fullStr Validation of total skin electron irradiation (TSEI) technique dosimetry data by Monte Carlo simulation
title_full_unstemmed Validation of total skin electron irradiation (TSEI) technique dosimetry data by Monte Carlo simulation
title_short Validation of total skin electron irradiation (TSEI) technique dosimetry data by Monte Carlo simulation
title_sort validation of total skin electron irradiation (tsei) technique dosimetry data by monte carlo simulation
topic Radiation Measurements
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5690047/
https://www.ncbi.nlm.nih.gov/pubmed/27455502
http://dx.doi.org/10.1120/jacmp.v17i4.6230
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AT danielshahar validationoftotalskinelectronirradiationtseitechniquedosimetrydatabymontecarlosimulation
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