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Vegari A, Abdisaray A, Mostafanejad K, Jabbari N. High-density polyethylene (HDPE)-incorporated boron carbide and boric acid nanoparticles as a nanoshield of photoneutrons from medical linear accelerators. Int J Radiat Biol 2024; 100:609-618. [PMID: 38190436 DOI: 10.1080/09553002.2023.2295964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 11/27/2023] [Indexed: 01/10/2024]
Abstract
PURPOSE The current study aimed to investigate boron carbide and boric acid nanoparticles (NPs) as absorbents for thermal neutrons and high-density polyethylene (HDPE) as a substrate and neutron moderator for fast neutrons. The goal was to assess the performance of boron carbide and boric acid NPs based on HDPE as a nanoshield of photoneutrons from medical linear accelerators. MATERIALS AND METHODS This study was conducted in two parts of simulation and practice. The Monte Carlo (MC) simulation involved modeling and verification of the single-layer, double-layer, and combined nanoshields by selecting nanomaterials and substrates and, finally, calculating the macroscopic cross-sections. The practical part involved manufacturing nanoshields based on the simulation results and evaluating the manufactured nanocomposites via experimental measurements. RESULTS MC simulation results with an uncertainty of less than 1% showed that for the monolayer samples, the best result belonged to boron carbide at a concentration of 10% and a macroscopic cross-section of 0.933 cm-1. At a concentration of 20%, the highest value among the double-layer samples was 0.936 cm-1 and for the combined samples, this value was 0.928 cm-1. Boron carbide single-layer nanocomposites at a 10% concentration, as well as the bilayer nanoshield of 10% boron carbide and 20% boric acid performed well; however, the best performance belonged to the nanoshield with a macroscopic cross-section of 0.960 and the combination containing 5% boron carbide and 10% boric acid. CONCLUSIONS The research suggests that utilizing boron carbide and boric acid nanoshields in combination with HDPE holds promise as a viable approach to protecting from the photoneutrons. Further exploration of these nanocomposite shields and their practical applications is warranted, with the potential to yield significant advancements in radiation therapy safety and efficacy.
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Affiliation(s)
- Ali Vegari
- Department of Medical Physics, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Akbar Abdisaray
- Department of Physics, Faculty of Sciences, Urmia University, Urmia, Iran
| | | | - Nasrollah Jabbari
- Solid Tumor Research Center, Cellular and Molecular Medicine Institute, Urmia University of Medical Sciences, Urmia, Iran
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Sohrabi M, Hakimi A. Spectrometry of leakage photoneutrons of 18 MV medical accelerator head by Sohrabi passive multi-directional spherical neutron spectrometry system. Phys Med 2022; 99:120-129. [DOI: 10.1016/j.ejmp.2022.04.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 04/24/2022] [Accepted: 04/27/2022] [Indexed: 10/18/2022] Open
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Sohrabi M, Ebrahimzadeh Torkamani M, Ali Nedaie H. Whole-body photoneutron 360° angular distribution dosimetry by novel "Sohrabi neutron dosimetry methods". Phys Med 2022; 95:167-175. [PMID: 35183907 DOI: 10.1016/j.ejmp.2022.02.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 01/24/2022] [Accepted: 02/01/2022] [Indexed: 11/28/2022] Open
Abstract
PURPOSE Whole-body photoneutron (PN) energy-specific dosimetry on phantom surfaces and 360°angular fast PN distribution dosimetry on and around polyethylene (PE) phantom organs for prostate cancer in 10 cm × 10 cm and 20 cm × 20 cm field sizes of 18 MV X-rays of Varian Clinac 2100C linear accelerator. METHODS Novel "Sohrabi neutron dosimetry methods" including "miniature passive neutron dosimeter/spectrometer" and "strip polycarbonate neutron dosimeters" were applied. Energy-specific PN dose equivalents on surface as well as 360°fast PN dose equivalent angular distributions on and around PE phantom organs; head, neck, thorax, arms, pelvis, thighs and legs were determined. RESULTS Matrix of surface (skin) energy-specific PN dose equivalents including total thermal, total epithermal, total fast, sum total thermal + epithermal and sum total thermal + epithermal + fast, and 360°angular fast PN dose equivalent responses were determined. The results indicate that data matrix of 20 cm × 20 cm field size provides higher PN dose equivalent values than those of 10 cm × 10 cm field size for surface points even remote from the central axis and for all 360°angular fast PN dose equivalent distributions on organs studied. CONCLUSIONS Matrix of energy-specific PN dose equivalents was obtained demonstrating that the Sohrabi neutron dosimetry methods applied are unique for energy-specific PN dose equivalent studies as well as for 360°angular PN dose equivalent distribution data for PN-SPC risk estimation. The dosimetry methods can be specifically applied to many other exotic applications in health physics, medical physics, space flight dosimetry, and nuclear science and technology.
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Affiliation(s)
- Mehdi Sohrabi
- Health Physics and Dosimetry Research Laboratory, Department of Energy Engineering and Physics, Amirkabir University of Technology, Tehran, Iran.
| | - Morteza Ebrahimzadeh Torkamani
- Health Physics and Dosimetry Research Laboratory, Department of Energy Engineering and Physics, Amirkabir University of Technology, Tehran, Iran
| | - Hassan Ali Nedaie
- Department of Radiotherapy Oncology, Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran
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Elmtalab S, Shanei A, Choopan Dastjerdi MH, Brkić H, Abedi I, Amouheidari A. OUP accepted manuscript. RADIATION PROTECTION DOSIMETRY 2022; 198:129-138. [PMID: 35137234 DOI: 10.1093/rpd/ncac001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 12/27/2021] [Accepted: 01/03/2022] [Indexed: 11/12/2022]
Affiliation(s)
- Soheil Elmtalab
- Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Ahmad Shanei
- Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | | | - Hrvoje Brkić
- Department of biophysics and radiology, Faculty of Medicine, J. J. Strossmayer University of Osijek, Osijek, Croatia
- Department of biophysics, biology and chemistry, Faculty of dental medicine and health, J. J. Strossmayer University of Osijek, Osijek, Croatia
| | - Iraj Abedi
- Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Alireza Amouheidari
- Department of Radiation Oncology, Isfahan Milad General Hospital, Isfahan, Iran
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Sohrabi M, Torkamani ME. Breakthrough whole body energy-specific and tissue-specific photoneutron dosimetry by novel miniature neutron dosimeter/spectrometer. Sci Rep 2021; 11:20552. [PMID: 34654858 PMCID: PMC8519960 DOI: 10.1038/s41598-021-99612-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 09/28/2021] [Indexed: 11/09/2022] Open
Abstract
Breakthrough whole body energy-specific photoneutron (PN) dosimetry was made in/out-of-field in polyethylene phantom organ surface/depths remote from isocenter of 10 × 10 cm2 field prostate cancer therapy in 18 MV X-rays Varian Clinac 2100C medical linear accelerator for PN tissue-specific second primary cancer (PN-SPC) risk estimation. A novel miniature neutron dosimeter/spectrometer with polycarbonate/10B/cadmium inserts was invented and applied. Each dosimeter determines seven tissue-specific dose equivalent (mSv)/Gy X-ray dose at each measurement point providing seven major energy-specific responses for beam thermal, albedo thermal, total thermal, total epithermal, total fast, sum of totals (thermal + epithermal) and sum of totals (thermal + epithermal + fast) PNs dose equivalents. The neutron dosimeter is simple, efficient, and unique with high spatial resolution and provides matrix of energy-specific PN dose equivalent (mSv)/Gy X-ray dose on surface and organ depths for tissue-specific PN-SPC risk estimation. The dosimeter also performs like a "miniature neutron spectrometer" and is unique for other applications in health physics in particular individual neutron dosimetry, medical physics, space flights, science and technology.
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Affiliation(s)
- Mehdi Sohrabi
- Health Physics and Dosimetry Research Laboratory, Department of Energy Engineering and Physics, Amirkabir University of Technology, Tehran, Iran.
| | - Morteza Ebrahimzadeh Torkamani
- Health Physics and Dosimetry Research Laboratory, Department of Energy Engineering and Physics, Amirkabir University of Technology, Tehran, Iran
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Mohammadi S, Behmadi M, Mohammadi A, Toossi MTB. THERMAL AND FAST NEUTRON DOSE EQUIVALENT DISTRIBUTION MEASUREMENT OF 15-MV LINEAR ACCELERATOR USING A CR-39 NUCLEAR TRACK DETECTORS. RADIATION PROTECTION DOSIMETRY 2020; 188:503-507. [PMID: 32025737 DOI: 10.1093/rpd/ncaa001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 12/07/2019] [Accepted: 12/26/2019] [Indexed: 06/10/2023]
Abstract
The main purpose of this study is to measure the contribution of the thermal and fast neutron dose along the central axis of the 15 MV Elekta Precise linac in a tissue equivalent phantom. In order to achieve this purpose, different points were selected in three field sizes of 5 × 5 cm2, 10 × 10 cm2 and 15 × 15 cm2. Fast and thermal neutrons were measured using CR-39 nuclear track detectors with and without thermal neutron converter of 10B, respectively. According to the results, the fast neutron dose equivalent was decreased as the depth increased (field size 5 × 5, 10 × 10 and 15 × 15 cm2 fall from 0.35 to 0.15, 0.5 to 0.3 and 0.5 to 0.3, respectively). Thermal dose equivalent was increased as the depth increased in the tissue equivalent phantom (field size 5 × 5, 10 × 10 and 15 × 15 cm2 rise from 0.1 to 0.4, 0.4 to 0.8 and 0.4 to 0.9, respectively). In conclusion, at depth <3 cm, most existing neutrons are fast and CR-39 films are sensitive to fast neutrons; therefore, they are more appropriate than thermoluminescent dosemeters in measuring neutron dose equivalent.
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Affiliation(s)
- Sara Mohammadi
- Medical Physics Department, Faculty of Medicine, Gonabad University of Medical Sciences, Gonabad, Iran
- Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Marziyeh Behmadi
- Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
- Medical Physics Department, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Aghil Mohammadi
- Energy Engineering and Physics Department, Amir Kabir University of Technology, Tehran, Iran
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In-field radiation contamination during intraoperative electron radiation therapy with a dedicated accelerator. Appl Radiat Isot 2020; 155:108918. [DOI: 10.1016/j.apradiso.2019.108918] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 09/05/2019] [Accepted: 10/02/2019] [Indexed: 01/30/2023]
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Karimi AH, Brkić H, Shahbazi-Gahrouei D, Haghighi SB, Jabbari I. Essential considerations for accurate evaluation of photoneutron contamination in Radiotherapy. Appl Radiat Isot 2018; 145:24-31. [PMID: 30572262 DOI: 10.1016/j.apradiso.2018.12.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 11/07/2018] [Accepted: 12/04/2018] [Indexed: 10/27/2022]
Abstract
Nowadays, high-energy X-rays produced by medical linear accelerators (LINACs) are widely used in many Radiation Therapy (RT) centers. High-energy photons (> 8 MeV) produce undesired neutrons in the LINAC head which raise concerns about unwanted neutron dose to the patients and RT personnel. Regarding the significance of radiation protection in RT, it is important to evaluate photoneutron contamination inside the RT room. Unfortunately, neutron dosimeters used for this purpose have limitations that can under the best conditions cause to > 10% uncertainty. In addition to this uncertainty, the present Monte Carlo (MC) study introduces another uncertainty in measurements (nearly up to 20%) when neutron ambient dose equivalent (Hn*(10)) is measured at the patient table or inside the maze and the change in neutron energy is ignored. This type of uncertainty can even reach 35% if Hn*(10) is measured by dosimeters covered by a layer of 10B as converter. So, in these cases, neglecting the change in neutron energy can threaten the credibility of measured data and one should attend to this energy change in order to reduce measurement uncertainty to the possible minimum. This study also discusses the change in neutron spectra and Hn*(10) at the patient table caused by removing a typical RT room from MC simulations. Under such conditions, neutron mean energy (Ēn) overestimated by 0.2-0.4 MeV at the patient table. Neutron fluence (φn) at the isocenter (IC) was underestimated by 23-54% for different field sizes that caused Hn*(10) to be miscalculated up to 24%. This finding informs researchers that for accurate evaluation of Hn*(10) at the patient table, simulating the RT room is an effective parameter in MC studies.
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Affiliation(s)
- Amir Hossein Karimi
- Department of Medical Physics, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
| | - Hrvoje Brkić
- Department of Biophysics and Radiology, Faculty of Medicine, University of J.J. Strossmayer, Osijek, Croatia; Department of Biophysics and Radiology, Faculty of Dental Medicine and Health, University of J.J. Strossmayer, Osijek, Croatia
| | - Daryoush Shahbazi-Gahrouei
- Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
| | - Somayeh Biparva Haghighi
- Department of General Courses, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Iraj Jabbari
- Department of Nuclear Engineering, Faculty of Advanced Sciences and Technologies, University of Isfahan, Isfahan, Iran
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Effect of each component of a LINAC therapy head on neutron and photon spectra. Appl Radiat Isot 2018; 139:40-45. [PMID: 29704704 DOI: 10.1016/j.apradiso.2018.04.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 04/07/2018] [Accepted: 04/16/2018] [Indexed: 11/22/2022]
Abstract
Linear accelerators (LINACs) are widely applied in radiotherapy for their versatility and flexibility. Monte Carlo simulations were made to find the neutron and photon spectra at the isocenter (IC) of a LINAC operating at 10, 15, 18, and 24 MV by the MCNPX code. A detailed model of the LINAC head, consisting of flattening filter, secondary collimator, primary collimator, and multi-leaf collimator were used in the calculations. The effect of eliminating any of these components on contamination of a neutron spectrum and a photon spectrum was assessed. Photon and neutron ambient equivalent doses were found, and comparisons were made for the various structures. Lethargy neutron spectra at the IC were compared with spectra computed with the function reported by Tosi et al., which describes well neutron spectra for the energy region beyond 1 MeV, although tending to undervalue energy spectra below 1 MeV. The findings show that the photon and neutron fluences are enhanced when eliminating a LINAC component. The neutron and photon doses increased except when removing the primary collimator.
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Khabaz R, Boodaghi R, Benam MR, Zanganeh V. Estimation of photoneutron dosimetric characteristics in tissues/organs using an improved simple model of linac head. Appl Radiat Isot 2018; 133:88-94. [DOI: 10.1016/j.apradiso.2017.12.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Revised: 12/24/2017] [Accepted: 12/27/2017] [Indexed: 10/18/2022]
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Abou-Taleb WM, Hassan MH, El Mallah EA, Kotb SM. MCNP5 evaluation of photoneutron production from the Alexandria University 15 MV Elekta Precise medical LINAC. Appl Radiat Isot 2018; 135:184-191. [PMID: 29413836 DOI: 10.1016/j.apradiso.2018.01.036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 01/24/2018] [Accepted: 01/25/2018] [Indexed: 10/17/2022]
Abstract
Photoneutron production, and the dose equivalent, in the head assembly of the 15 MV Elekta Precise medical linac; operating in the faculty of Medicine at Alexandria University were estimated with the MCNP5 code. Photoneutron spectra were calculated in air and inside a water phantom to different depths as a function of the radiation field sizes. The maximum neutron fluence is 3.346×10-9 n/cm2-e for a 30×30 cm2 field size to 2-4 cm-depth in the phantom. The dose equivalent due to fast neutron increases as the field size increases, being a maximum of 0.912 ± 0.05 mSv/Gy at depth between 2 and 4 cm in the water phantom for 40×40 cm2 field size. Photoneutron fluence and dose equivalent are larger to 100 cm from the isocenter than to 35 cm from the treatment room wall.
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Affiliation(s)
- W M Abou-Taleb
- Physics and Chemistry Department, Faculty of Education, Alexandria University, Alexandria, Egypt.
| | - M H Hassan
- Nuclear and Radiation Engineering Department, Alexandria University, Egypt.
| | - E A El Mallah
- Physics Department, Faculty of Science, Alexandria University, Alexandria, Egypt.
| | - S M Kotb
- Physics and Chemistry Department, Faculty of Education, Alexandria University, Alexandria, Egypt.
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Ezzati AO, Studenski MT. Neutron damage induced in cardiovascular implantable electronic devices from a clinical 18 MV photon beam: A Monte Carlo study. Med Phys 2017; 44:5660-5666. [DOI: 10.1002/mp.12581] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 07/27/2017] [Accepted: 09/01/2017] [Indexed: 11/06/2022] Open
Affiliation(s)
- Ahad Ollah Ezzati
- Department of Physics; University of Tabriz; 29 Bahman Blvd. Tabriz 5166616471 Iran
| | - Matthew T. Studenski
- Department of Radiation Oncology; University of Miami; 1475 NW 12 Ave. Suite 1500 Miami FL 33136 USA
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Fast, epithermal and thermal photoneutron dosimetry in air and in tissue equivalent phantom for a high-energy X-ray medical accelerator. Z Med Phys 2017; 28:49-62. [PMID: 28546005 DOI: 10.1016/j.zemedi.2017.04.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 04/16/2017] [Accepted: 04/17/2017] [Indexed: 12/14/2022]
Abstract
Photoneutron (PN) dosimetry in fast, epithermal and thermal energy ranges originated from the beam and albedo neutrons in high-energy X-ray medical accelerators is highly important from scientific, technical, radiation protection and medical physics points of view. Detailed dose equivalents in the fast, epithermal and thermal PN energy ranges in air up to 2m as well as at 35 positions from the central axis of 12 cross sections of the phantom at different depths were determined in 18MV X-ray beams of a Siemens ONCOR accelerator. A novel dosimetry method based on polycarbonate track dosimeters (PCTD)/10B (with/without cadmium cover) was used to determine and separate different PN dose equivalents in air and in a multilayer polyethylene phantom. Dose equivalent distributions of PNs, as originated from the main beam and/or albedo PNs, on cross-plane, in-plane and diagonal axes in 10cm×10cm fields are reported. PN dose equivalent distributions on the 3 axes have their maxima at the isocenter. Epithermal and thermal PN depth dose equivalent distributions in the phantom for different positions studied peak at ∼3cm depth. The neutron dosimeters used for the first time in such studies are highly effective for separating dose equivalents of PNs in the studied energy ranges (beam and/or albedo). The PN dose equivalent data matrix made available in this paper is highly essential for detailed patient dosimetry in general and for estimating secondary cancer risks in particular.
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Hernandez-Adame L, Contreras-Sandoval H, Vega-Carrillo HR, Landeros LHP. Design of a Treatment Room for an 18-MV Linac. NUCL TECHNOL 2017. [DOI: 10.13182/nt11-a12277] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Luis Hernandez-Adame
- Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares Apartado Postal 336, Zacatecas, 98000, Mexico
| | - Hector Contreras-Sandoval
- Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares Apartado Postal 336, Zacatecas, 98000, Mexico
| | - Hector Rene Vega-Carrillo
- Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares Apartado Postal 336, Zacatecas, 98000, Mexico
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Ezzati A, Studenski M. Neutron dose in and out of 18 MV photon fields. Appl Radiat Isot 2017; 122:186-192. [DOI: 10.1016/j.apradiso.2017.01.046] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 01/21/2017] [Accepted: 01/27/2017] [Indexed: 10/20/2022]
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Measurement of Photo-Neutron Dose from an 18-MV Medical Linac Using a Foil Activation Method in View of Radiation Protection of Patients. NUCLEAR ENGINEERING AND TECHNOLOGY 2016. [DOI: 10.1016/j.net.2015.11.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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17
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Induced radioisotopes in a linac treatment hall. Appl Radiat Isot 2015; 102:103-108. [DOI: 10.1016/j.apradiso.2015.05.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2014] [Revised: 05/10/2015] [Accepted: 05/10/2015] [Indexed: 11/19/2022]
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18
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Neutron spectrometry and determination of neutron contamination around the 15 MV Siemens Primus LINAC. J Radioanal Nucl Chem 2015. [DOI: 10.1007/s10967-015-3944-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Mohammadi N, Miri-Hakimabad H, Rafat-Motavalli L, Akbari F, Abdollahi S. Patient-specific voxel phantom dosimetry during the prostate treatment with high-energy linac. J Radioanal Nucl Chem 2014. [DOI: 10.1007/s10967-014-3872-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Alem-Bezoubiri A, Bezoubiri F, Badreddine A, Mazrou H, Lounis-Mokrani Z. Monte Carlo estimation of photoneutrons spectra and dose equivalent around an 18MV medical linear accelerator. Radiat Phys Chem Oxf Engl 1993 2014. [DOI: 10.1016/j.radphyschem.2013.07.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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21
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Khabaz R. Investigation of the effects of beam divergence on the response of neutron voluminous detectors. J Radioanal Nucl Chem 2014. [DOI: 10.1007/s10967-014-3084-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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22
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Secondary radiation dose during high-energy total body irradiation. Strahlenther Onkol 2014; 190:459-66. [DOI: 10.1007/s00066-014-0635-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 11/28/2013] [Indexed: 10/25/2022]
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24
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Karimi-Shahri K, Rafat-Motavalli L, Miri-Hakimabad H. Study of size, type and the kerma approximation for thermoluminescent dosimetry. J Radioanal Nucl Chem 2013. [DOI: 10.1007/s10967-013-2580-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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25
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Quantifying the geometry correction factor and effectiveness parameter for Bonner sphere spectrometer with 3He counter. J Radioanal Nucl Chem 2013. [DOI: 10.1007/s10967-012-2286-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Study of a new multi-sphere spectrometer based on water moderator with a high efficiency 6LiI(Eu) detector. J Radioanal Nucl Chem 2012. [DOI: 10.1007/s10967-012-1748-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Kalef-Ezra JA. Health physics aspects in treatment rooms after 18-MV X-ray irradiations. RADIATION PROTECTION DOSIMETRY 2011; 147:281-286. [PMID: 21979431 DOI: 10.1093/rpd/ncr361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Delayed activation products contribute to the exposure of the staff operating high-energy accelerators. Induced activity was studied in a treatment room following 18-MV X-ray irradiations using a hand-held system that allows both dose rate measurements and spectroscopic analysis. The major activation products and the corresponding nuclear reactions were identified. At the majority of the studied locations, β(+) emitters were the main short-term dose contributors. The time variation of the absorbed dose rate in a treatment room during the first 20-min post-irradiation was represented by the sum of two exponential components with half-lives of 1-2 min and either 4 or 10 min, depending on the location in the room. Components with a half-life of hours or days contribute <1 % to the initial dose rate. The activation of some accessories, such as iron filters and portal imagers, deserve special attention. The collection of such data with the proposed method allows the development of optimised working protocols at each treatment room.
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Affiliation(s)
- John A Kalef-Ezra
- Medical Physics Department, University of Ioannina and Ioannina University Hospital, 45510 Ioannina, Greece.
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