1
|
Ardiny H, Beigzadeh A, Askari M. Detecting and tracking multiple mobile radioactive sources by data fusion of a surveillance camera and a sodium iodide (NaI) detector. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:125111. [PMID: 36586955 DOI: 10.1063/5.0122498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 11/24/2022] [Indexed: 06/17/2023]
Abstract
Nowadays, the use of radioactive materials has increased due to recent progress in nuclear technology, but concerns about the missing or smuggling of radioactive materials have persisted. Nuclear threats such as terrorist attacks or the malicious use of radioactive materials out of regulatory control (MORC) are always severe problems that can result in adverse environmental, health, economic, and security effects. Applying new technologies to monitor and track MORC will prevent radioactive materials from being illegally transported across borders or from one place to another. In this research, we have constructed a detection system to automatically and remotely localize multiple mobile gamma-emitting radiation sources among other objects by combining an IP camera and a sodium iodide detector. An algorithm for the detection system has been developed to identify the objects' paths from camera data and correlate radiation data with the paths to detect contaminated objects. We evaluated the system using two weak radioactive sources (Co-60, Cs-137), which were hidden on moving objects, and succeeded in finding harmful targets. The results have also shown that by increasing the number of contaminated sources from one to two, the detection accuracy decreases by about 2.5 times. However, by doubling the speed of mobile targets, the detection accuracy improved by about 30%. Detecting and tracking MORC with a single detection system is limited to small regions. By equipping many surveillance cameras in a city with relatively inexpensive radioactive detectors, a network sensing system is established to find radioactive hotspots in a smart city.
Collapse
Affiliation(s)
- Hadi Ardiny
- Radiation Application Research School, Nuclear Science and Technology Research Institute, AEOI, P.O. Box 1339-14155, Tehran, Iran
| | - Amirmohammad Beigzadeh
- Radiation Application Research School, Nuclear Science and Technology Research Institute, AEOI, P.O. Box 1339-14155, Tehran, Iran
| | - Mojtaba Askari
- Radiation Application Research School, Nuclear Science and Technology Research Institute, AEOI, P.O. Box 1339-14155, Tehran, Iran
| |
Collapse
|
2
|
Banaee N, Goodarzi K, Nedaie HA. Neutron contamination in radiotherapy processes: a review study. JOURNAL OF RADIATION RESEARCH 2021:rrab076. [PMID: 34467374 DOI: 10.1093/jrr/rrab076] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 05/25/2021] [Indexed: 05/27/2023]
Abstract
Using high-energy photon beams is one of the most practical methods in radiotherapy treatment of cases in deep site located tumors. In such treatments, neutron contamination induced through photoneutron interaction of high energy photons (>8 MeV) with high Z materials of LINAC structures is the most crucial issue which should be considered. Generated neutrons will affect shielding calculations and cause extra doses to the patient and the probability of increase induced secondary cancer risks. In this study, different parameters of neutron production in radiotherapy processes will be reviewed.
Collapse
Affiliation(s)
- Nooshin Banaee
- Medical Radiation Research Center, Central Tehran Branch, Islamic Azad University, Tehran 1469669191, Iran
| | - Kiarash Goodarzi
- Department of Medical Radiation Engineering, Central Tehran Branch, Islamic Azad University, Tehran 1469669191, Iran
| | - Hassan Ali Nedaie
- Radiation Oncology Research Centre, Cancer Institute, Tehran University of Medical Sciences, Tehran 1417613151, Iran
| |
Collapse
|
3
|
Measurement of neutron dose in the compensator IMRT treatment. Appl Radiat Isot 2017; 128:136-141. [DOI: 10.1016/j.apradiso.2017.06.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 06/07/2017] [Accepted: 06/08/2017] [Indexed: 11/21/2022]
|
4
|
Arbor N, Higueret S, Elazhar H, Combe R, Meyer P, Dehaynin N, Taupin F, Husson D. Real-time detection of fast and thermal neutrons in radiotherapy with CMOS sensors. Phys Med Biol 2017; 62:1920-1934. [PMID: 28192285 DOI: 10.1088/1361-6560/aa5bc9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The peripheral dose distribution is a growing concern for the improvement of new external radiation modalities. Secondary particles, especially photo-neutrons produced by the accelerator, irradiate the patient more than tens of centimeters away from the tumor volume. However the out-of-field dose is still not estimated accurately by the treatment planning softwares. This study demonstrates the possibility of using a specially designed CMOS sensor for fast and thermal neutron monitoring in radiotherapy. The 14 microns-thick sensitive layer and the integrated electronic chain of the CMOS are particularly suitable for real-time measurements in γ/n mixed fields. An experimental field size dependency of the fast neutron production rate, supported by Monte Carlo simulations and CR-39 data, has been observed. This dependency points out the potential benefits of a real-time monitoring of fast and thermal neutron during beam intensity modulated radiation therapies.
Collapse
Affiliation(s)
- Nicolas Arbor
- Université de Strasbourg, IPHC, 23 rue du Loess 67037 Strasbourg, France. CNRS, UMR7178, 67037 Strasbourg, France
| | | | | | | | | | | | | | | |
Collapse
|
5
|
Çeçen Y, Gülümser T, Yazgan Ç, Dapo H, Üstün M, Boztosun I. Photoneutron Flux Measurement via Neutron Activation Analysis in a Radiotherapy Bunker with an 18 MV Linear Accelerator. EPJ WEB OF CONFERENCES 2017. [DOI: 10.1051/epjconf/201715307006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
6
|
Králík M, Šolc J, Vondráček V, Šmoldasová J, Farkašová E, Tichá I. Spectral fluence of neutrons generated by radiotherapeutic linacs. RADIATION PROTECTION DOSIMETRY 2015; 163:373-380. [PMID: 24925899 DOI: 10.1093/rpd/ncu192] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Spectral fluences of neutrons generated in the heads of the radiotherapeutic linacs Varian Clinac 2100 C/D and Siemens ARTISTE were measured by means of the Bonner spheres spectrometer whose active detector of thermal neutrons was replaced by an activation detector, i.e. a tablet made of pure manganese. Measurements with different collimator settings reveal an interesting dependence of neutron fluence on the area defined by the collimator jaws. The determined neutron spectral fluences were used to derive ambient dose equivalent rate along the treatment coach. To clarify at which components of the linac neutrons are mainly created, the measurements were complemented with MCNPX calculations based on a realistic model of the Varian Clinac.
Collapse
Affiliation(s)
- Miloslav Králík
- Czech Metrology Institute, Prague 10 CZ-102 00, Czech Republic
| | - Jaroslav Šolc
- Czech Metrology Institute, Prague 10 CZ-102 00, Czech Republic
| | | | - Jana Šmoldasová
- Czech Metrology Institute, Prague 10 CZ-102 00, Czech Republic
| | - Estera Farkašová
- Thomayer's Hospital, Vídeňská 80, Prague 4 CZ-140 59, Czech Republic
| | - Ivana Tichá
- Thomayer's Hospital, Vídeňská 80, Prague 4 CZ-140 59, Czech Republic
| |
Collapse
|
7
|
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]
|
8
|
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]
|
9
|
Salgado A, Pereira W, da Fonseca E, Patrão K, Batista D. Calibration and evaluation of neutron survey meters used at linac facility. RADIAT MEAS 2010. [DOI: 10.1016/j.radmeas.2010.06.033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
10
|
Naseri A, Mesbahi A. A review on photoneutrons characteristics in radiation therapy with high-energy photon beams. Rep Pract Oncol Radiother 2010; 15:138-44. [PMID: 24376940 DOI: 10.1016/j.rpor.2010.08.003] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Revised: 08/09/2010] [Accepted: 08/19/2010] [Indexed: 11/26/2022] Open
Abstract
In radiation therapy with high-energy photon beams (E > 10 MeV) neutrons are generated mainly in linacs head thorough (γ,n) interactions of photons with nuclei of high atomic number materials that constitute the linac head and the beam collimation system. These neutrons affect the shielding requirements in radiation therapy rooms and also increase the out-of-field radiation dose of patients undergoing radiation therapy with high-energy photon beams. In the current review, the authors describe the factors influencing the neutron production for different medical linacs based on the performed measurements and Monte Carlo studies in the literature.
Collapse
Affiliation(s)
- Alireza Naseri
- Radiation Therapy Department, Imam Hospital, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Asghar Mesbahi
- Radiation Therapy Department, Imam Hospital, Tabriz University of Medical Sciences, Tabriz, Iran ; Medical Physics Department, Medical School, Tabriz University of Medical Sciences, Tabriz, Iran
| |
Collapse
|
11
|
A neutron track etch detector for electron linear accelerators in radiotherapy. Radiol Oncol 2010; 44:62-6. [PMID: 22933893 PMCID: PMC3423670 DOI: 10.2478/v10019-010-0003-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2009] [Accepted: 11/16/2009] [Indexed: 11/27/2022] Open
Abstract
Background Electron linear accelerators in medical radiotherapy have replaced cobalt and caesium sources of radiation. However, medical accelerators with photon energies over 10 MeV generate undesired fast neutron contamination in a therapeutic X-ray photon beam. Photons with energies above 10 MeV can interact with the atomic nucleus of a high-Z material, of which the target and the head of an accelerator consist, and lead to the neutron ejection. Results and conclusions. Our neutron dosimeter, composed of the LR-115 track etch detector and boron foil BN-1 converter, was calibrated on thermal neutrons generated in the nuclear reactor of the Josef Stefan Institute (Slovenia), and applied to dosimetry of undesirable neutrons in photon radiotherapy by the linear accelerator 15 MV Siemens Mevatron. Having considered a high dependence of a cross-section between neutron and boron on neutron energy, and broad neutron spectrum in a photon beam, as well as outside the entrance door to maze of the Mevatron, we developed a method for determining the effective neutron detector response. A neutron dose rate in the photon beam was measured to be 1.96 Sv/h. Outside the Mevatron room the neutron dose rate was 0.62 μSv/h. PACS: 87.52. Ga; 87.53.St; 29.40.Wk.
Collapse
|
12
|
Králík M, Turek K, Vondrácek V. Spectra of photoneutrons produced by high-energy X-ray radiotherapy linacs. RADIATION PROTECTION DOSIMETRY 2008; 132:13-17. [PMID: 18940821 DOI: 10.1093/rpd/ncn278] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Spectral fluence of photoneutrons generated in the head of the radiotherapeutic linac Varian 2100 C/D was measured by means of the Bonner spheres spectrometer whose active detector of thermal neutrons was replaced by a track detector, i.e. a sandwich of four CR-39s with the boron radiator inserted between them. Measurements with different collimator settings showed that the fluence of photoneutrons was higher for the more open collimator.
Collapse
Affiliation(s)
- M Králík
- Inspectorate for Ionizing Radiation, Czech Metrology Institute, Radiová 1, CZ 102 00 Prague 10, Czech Republic.
| | | | | |
Collapse
|
13
|
Al-Ghamdi H, Fazal-ur-Rehman, Al-Jarallah M, Maalej N. Photoneutron intensity variation with field size around radiotherapy linear accelerator 18-MeV X-ray beam. RADIAT MEAS 2008. [DOI: 10.1016/j.radmeas.2008.03.065] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
14
|
Esposito A, Bedogni R, Lembo L, Morelli M. Determination of the neutron spectra around an 18MV medical LINAC with a passive Bonner sphere spectrometer based on gold foils and TLD pairs. RADIAT MEAS 2008. [DOI: 10.1016/j.radmeas.2007.10.035] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
15
|
Knösel M, Attin R, Kubein-Meesenburg D, Sadat-Khonsari R. Cephalometric assessment of the axial inclination of upper and lower incisors in relation to the third-order angle. J Orofac Orthop 2007; 68:199-209. [PMID: 17522804 DOI: 10.1007/s00056-007-0635-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2006] [Accepted: 11/27/2006] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND AIM Estimating incisor inclination cephalometrically by reference lines NA and NB puts the orthodontist in the difficult position of relating these axial inclination data to the bracket's third-order prescription which refers to a perpendicular to the occlusal plane. Purpose of the present study was to evaluate the relationship between the cephalometrically-assessed incisor inclination (using the lines NA and NB for reference) and the third-order angle (syn.: torque angle, TA) according to Andrews' description, and moreover to investigate the correlation between incisor inclination data and skeletal-sagittal and skeletal-vertical findings. MATERIALS AND METHODS The lateral cephalograms and corresponding dental casts of 67 subjects between 10 and 25 years of age (regardless of skeletal and dental relationships) were considered in the study. All subjects were Caucasian, and none had undergone orthodontic therapy. Upper (U1) and lower (L1) incisor angulations were cephalometrically assessed in reference to the NA and NB lines and compared to third-order angles obtained from dental cast measurements with an incisor inclination-recording appliance. Incisor inclination data from the two measurements were correlated to craniofacial sagittal (angles SNA, SNB, ANB) and vertical (angles NSL-NL, NSL-ML, ML-NL) findings from the radiographs. RESULTS The third-order angles in the upper arch measured on the dental casts were a mean of 16.2 degrees (SD = 5.3 degrees) smaller than the axial inclination according to the NA line; the lower incisor third-order data were less than those of the axial inclination according to the NB line by a mean of 27.8 degrees (SD = 4.75 degrees). In this sample, there was a range of 42.7 degrees for the U1TA variable (mean = 5.6 degrees, SD 9.73 degrees) and 47 degrees for U1NA/ degrees variable (mean = 21.71 degrees, SD = 8.67 degrees). The L1TA variable showed a range of 29 degrees (mean = -2.95 degrees, SD = 7.17 degrees), the radiographic L1NB/ degrees range was 23 degrees (mean = 24.91 degrees, SD = 5.8 degrees). We observed a highly significant correlation (r(NA) = 0.84***, r(NB) = 0.76***) between the Andrews' angle and the inclination estimated in reference to the NA and NB lines. No significant correlation between incisor inclination and craniofacial measurements was detected. CONCLUSIONS Dental cast measurements seem to be more precise and more valid than lateral radiographs. The method we describe enables clinicians to get a good idea precisely and quickly of how much torque potential remains in the brackets and archwires during treatment. The inclination of the incisors can also be calculated using the regression equations provided, making additional lateral cephalograms unnecessary.
Collapse
Affiliation(s)
- Michael Knösel
- Department of Orthodontics, Center of Dentistry, University Hospital, Göttingen, Germany.
| | | | | | | |
Collapse
|
16
|
Chen J. Extended conversion coefficients for use in radiation protection of the embryo and fetus against external neutrons from 10 MeV to 100 GeV. HEALTH PHYSICS 2006; 90:223-31. [PMID: 16505619 DOI: 10.1097/01.hp.0000180776.45686.3b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
External neutron exposure is of concern in the environment and in some workplaces. Dose assessments for neutrons frequently rely on fluence-to-absorbed dose conversion coefficients. A problem of concern in radiation protection is exposure of pregnant women to ionizing radiation because of the high radiosensitivity of the embryo and fetus. While neutron fluence-to-dose conversion coefficients for adults are recommended in ICRP publications and ICRU reports, conversion coefficients for embryos and fetuses are not given in the publications. This study uses the Monte Carlo code MCNPX to determine mean absorbed doses to the embryo and fetus when the mother is exposed to neutron fields. A previous study has dealt with neutrons from 1 eV to 10 MeV. In this study, monoenergetic neutrons ranging from 10 MeV to 100 GeV are considered. The irradiation geometries include antero-posterior, postero-anterior, lateral, rotational, and isotropic. At each of these standard irradiation geometries, absorbed doses to the fetal brain and body are calculated for the embryo of 8 wk and the fetus of 3, 6, or 9 mo. Neutron fluence-to-absorbed dose conversion coefficients are derived for the four prenatal ages. The results showed that the fetus at about 3 mo of prenatal age should receive more radiation protection to prevent long-term brain damage. During prenatal life, the fetus generally receives the highest absorbed dose per unit neutron fluence for antero-posterior irradiation. In cases where the irradiation geometry is not specified or not adequately known, conversion coefficients of AP-irradiation can therefore be used in a conservative dose assessment of fetus exposure to external neutrons.
Collapse
Affiliation(s)
- Jing Chen
- Radiation Protection Bureau, Health Canada 6302Dl, 775 Brookfield Road, Ottawa KIA lCl, Canada.
| |
Collapse
|
17
|
Fernández F, Amgarou K, Domingo C, García M, Nourreddine A, Mouhssine D, Belafrites A, Ribaud I. A joint UAB-IReS-IPNO neutron comparison exercise with nuclear track detectors. RADIAT MEAS 2005. [DOI: 10.1016/j.radmeas.2004.12.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|