Does concrete composition affect photoneutron production inside radiation therapy bunkers?

Mesbahi, Asghar; Azarpeyvand, Ali-Asghar; Khosravi, Hossein

doi:10.1007/s11604-011-0030-y

Cited by 13 publications

(4 citation statements)

References 9 publications

(12 reference statements)

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“…There was no comparable study in the literature on this regard. However, our finding was in accordance with results of similar studies [10,16,19,21].…”

Section: Resultssupporting

confidence: 93%

Neutron and photon scattering properties of high density concretes used in radiation therapy facilities: A Monte Carlo study

Mesbahi

Khaldari

2017

Polish Journal of Medical Physics and Engineering

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In the current study the neutron and photon scattering properties of some newly developed high density concretes (HDCs) were calculated by using MCNPX Monte Carlo code. Five high-density concretes including Steel-Magnetite, Barite, Datolite-Galena, Ilmenite-ilmenite, Magnetite-Lead with the densities ranging from 5.11 g/cm 3 and ordinary concrete with density of 2.3 g/cm 3 were studied in our simulations. The photon beam spectra of 4 and 18 MV fromVarian linac and neutron spectra of clinical 18 MeV photon beam was used for calculations. The fluence of scattered photon and neutron from all studied concretes was calculated in different angles. Overall, the ordinary concrete showed higher scattered photons and Datolite-Galena concrete (4.42 g/cm 3 ) had the lowest scattered photons among all studied concretes. For neutron scattering, fluence at the angle of 180 was higher relative to other angles while for photons scattering fluence was maximum at 90 degree. The scattering fluence for photons and neutrons was dependent on the angle and composition of concrete. The results showed that the fluence of scattered photons and neutrons changes with the composition of high density concrete. Also, for high density concretes, the variation of scattered fluence with angle was very pronounced for neutrons but it changed slightly for photons. The results can be used for design of radiation therapy bunkers.

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“…There was no comparable study in the literature on this regard. However, our finding was in accordance with results of similar studies [10,16,19,21].…”

Section: Resultssupporting

confidence: 93%

Neutron and photon scattering properties of high density concretes used in radiation therapy facilities: A Monte Carlo study

Mesbahi

Khaldari

2017

Polish Journal of Medical Physics and Engineering

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“…18 The effect of different commercially available concretes on photo-neutron doses in the isocenter and entrance door of the maze revealed that the use of high-density concretes, in order to use more space in the radiotherapy bunker or other purposes, enhanced the neutron dose reached to the entrance door of the maze. 19 It was reported that the number of neutrons at the entrance door of the maze varied up to 36%, depending on the atomic composition of the concrete. In another study, evaluating the equivalent neutron dose produced by photo-neutrons inside primary barriers revealed that primary barrier shielding with a metal sheet for high energy photons, proper neutron shielding material should be constructed to reduce photo-neutron dose.…”

Section: Introductionmentioning

confidence: 99%

Monte Carlo Calculation of linear attenuation coefficients and photon scattering properties of novel concretes loaded with Osmium, Iridium and Barite nanoparticles

Jou

Mesbahi

Zamiri³

et al. 2021

Polish Journal of Medical Physics and Engineering

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Introduction: Recent studies have shown that the use of high-density nanoparticles (NPs) in concrete composition improves its radiation shielding properties. In the present study, the linear attenuation coefficients and photon scattering properties of newly developed high-density Nano-concretes have been calculated using the MCNPX Monte Carlo code. Material and methods: The shielding properties of Nano-concretes containing 10%, 20%, and 30% weight percentage of Osmium, Iridium and Barite NPs (100 nm) as well as ordinary concrete were investigated. The 6 and 18 MV photon beams of Varian Linac and 60 Co photons were used for simulation. Photon scattering flux was calculated for all Nano-concretes with 30 wt% of NPs and ordinary concrete at different angles. Results: In general, by adding Iridium, Osmium and Barite NPs to ordinary concrete, the linear attenuation coefficients increased. Despite a lower density relative to Iridium and Osmium, Nano-concretes containing Barite exhibited a higher linear attenuation coefficient due to their higher electron density. Conclusions: The results revealed a dependence between the scattered photon flux and the effective atomic number of Nano-concretes. With increasing the atomic number of fillers, the intensity of the scattered photon flux enlarged. Also, the scattered flux was higher for all types of concretes at 180 degrees relative to other angles.

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“…The effects of different types of concrete in doses due to photoneutrons in the isocenter and at the entrance door of the maze were conducted by Mesbahi and colleagues (Mesbahi et al 2011). Contributions concerning radiation scattered and build up produced by concrete shielding on patients undergoing prostate cancer treatment was performed by Braga and colleagues as well (Braga et al 2018).…”

Section: Introductionmentioning

confidence: 99%

Brazilian regulatory authority contribution to the shielding dimensioning model of radiotherapy rooms proposed by the NCRP 151

Braga¹,

Gomes²,

Terra³

et al. 2020

Biomed. Phys. Eng. Express

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The National Council on Radiation Protection and Measurements (NCRP) Report No. 151 is an essential document for bunker design commonly applied for radiotherapy treatment rooms. This document is used as a reference by several countries, including Brazil. The objective of this study is to evaluate the shielding dimensioning methodology recommended by NCRP 151, and compare it with the one adopted by the Brazilian regulatory authority. Radiotherapy rooms and respective doors were designed to use linear accelerators operating at 6, 10, 15, and 18 MeV under two different ways: (a) applying exclusively the methodology recommended by the NCRP 151, and (b) taking into consideration the complementary recommendations from the Brazilian authorities. The results suggest that designers in Brazil can count on at least 4 and 11% safety margin for dimensioning primary barriers in controlled and free areas respectively. Also 8% for secondary barriers in controlled areas, 9.7% for secondary barriers adjacent to the primary belt of free areas, and 6.6% for the lead of the doors.

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Does concrete composition affect photoneutron production inside radiation therapy bunkers?

Abstract: It can be concluded that application of high-density concretes in order to use limited space or for other purposes may cause higher neutron doses in the maze entrance door and consequently may impose stricter requirements for neutron shielding of maze entrance doors.

Cited by 13 publications

References 9 publications

Neutron and photon scattering properties of high density concretes used in radiation therapy facilities: A Monte Carlo study

Neutron and photon scattering properties of high density concretes used in radiation therapy facilities: A Monte Carlo study

Monte Carlo Calculation of linear attenuation coefficients and photon scattering properties of novel concretes loaded with Osmium, Iridium and Barite nanoparticles

Brazilian regulatory authority contribution to the shielding dimensioning model of radiotherapy rooms proposed by the NCRP 151

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