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Prasada DNY, Ciamaudi N, Fadli M, Tursinah R, Pawiro SA. Evaluation of the linac neutron dose profile for various depths and field sizes: a Monte Carlo study. Biomed Phys Eng Express 2021; 7. [PMID: 34619664 DOI: 10.1088/2057-1976/ac2dd5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 10/07/2021] [Indexed: 11/12/2022]
Abstract
High-energy medical linear accelerator (Linac) has been widely used for treating cancer patients. However, with its effectiveness, high-energy linac yields an undesirable amount of neutron contamination. An MCNPX code version 2.6.0 was used for calculating photoneutron contamination from Varian Clinac iX 15 MV linac heads in this study. The fast neutrons were dominantly produced inside the linac head. The neutron fluence, absorbed dose, and dose equivalent calculations occurred inside a linac head and a water phantom model. The fast neutrons begin to be moderated after 1 cm inside the water phantom by calculating the energy spectra. Variations in the field sizes from 2 × 2, 5 × 5, 10 × 10, and 15 × 15 cm2show that the neutron production yield would increase for larger field sizes. The maximum neutron dose equivalents are 3.745; 7.687; 11.794 and 14.197μSv/MU for 2 × 2, 5 × 5, 10 × 10 and 15 × 15 cm2field sizes, respectively. These calculations predict the photoneutron characteristics with more detail inside a treated patient during radiation therapy procedures.
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Affiliation(s)
- Dewa Ngurah Yudhi Prasada
- Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, Indonesia.,Department of Radiation Oncology, MRCCC Siloam Hospitals, Jakarta, Indonesia
| | - Nikita Ciamaudi
- Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, Indonesia
| | - Muhamad Fadli
- Department of Radiation Oncology, MRCCC Siloam Hospitals, Jakarta, Indonesia
| | - Rasito Tursinah
- Centre for Applied Nuclear Science and Technology, National Nuclear Energy Agency, Bandung, Indonesia
| | - Supriyanto Ardjo Pawiro
- Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, Indonesia
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Cheraghian M, Pourfallah T, Sabouri-Dodaran AA, Gholami M. Calculation of Photoneutron Contamination of Varian Linac in ICRU Soft-Tissue Phantom Using MCNPX Code. J Med Phys 2021; 46:116-124. [PMID: 34566292 PMCID: PMC8415253 DOI: 10.4103/jmp.jmp_40_21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/28/2021] [Accepted: 04/29/2021] [Indexed: 11/04/2022] Open
Abstract
Purpose The aim of this research was to calculate the fluence, dose equivalent (DE), and kerma of thermal, epithermal and fast photoneutrons separately, within ICRU soft-tissue-equivalent phantom in the radiotherapy treatment room, using MCNPX Monte Carlo code. Materials and Methods For this purpose, 18 MV Varian Linac 2100 C/D machine was simulated and desired quantities were calculated on the central axis and transverse directions at different depths. Results Maximum fluence, DE and kerma of total photoneutrons on central axis of the phantom were 43.8 n.cm-2.Gy-1, 0.26, and 3.62 mGy.Gy-1, at depths 2, 0.1, 0.1 cm, respectively. At any depth, average of fluence, DE and kerma in the outer area of the field were less than the inner area and in general were about 72%, 52%, and 45%, respectively. Conclusion According to this research, within the phantom; variation of fluence, DE and kerma in transverse direction were mild, and along the central axis at shallow area were sharp. DE of fast photoneutrons at shallow and deep areas were one order of magnitude greater than thermal photoneutrons.
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Affiliation(s)
| | - Tayyeb Pourfallah
- Department of Biochemistry, Biophysics and Genetics, Medical College, Mazandaran University of Medical Sciences, Sari, Iran.,Department of Medical Physics, Mazandaran University of Medical Sciences, Sari, Iran
| | | | - Mehrdad Gholami
- Department of Medical Physics, School of Allied Medical Sciences, Lorestan University of Medical Sciences, Khorramabad, Iran
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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.
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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
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Konefał A, Bieniasiewicz M, Wendykier J, Adamczyk S, Wrońska A. Additional radiation sources in a treatment and control room of medical linear accelerators. Radiat Phys Chem Oxf Engl 1993 2021. [DOI: 10.1016/j.radphyschem.2021.109513] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Abdul Aziz MZ, Yani S, Haryanto F, Ya Ali NK, Tajudin SM, Iwase H, Musarudin M. Monte Carlo simulation of X-ray room shielding in diagnostic radiology using PHITS code. JOURNAL OF RADIATION RESEARCH AND APPLIED SCIENCES 2020. [DOI: 10.1080/16878507.2020.1828020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- M Z Abdul Aziz
- Oncological and Radiological Sciences Cluster, Institut Perubatan Dan Pergigian Termaju (Advanced Medical and Dental Institute), Universiti Sains Malaysia, George Town, Malaysia
| | - S Yani
- Department of Physics, Faculty of Mathematics and Natural Sciences, IPB University (Bogor Agricultural University), Bogor, Indonesia
| | - F Haryanto
- Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Bandung, Indonesia
| | - N. Kamarullah Ya Ali
- Department of Radiology, Hospital Universiti Sains Malaysia, Universiti Sains Malaysia, Kelantan, Malaysia
| | - S. M. Tajudin
- Faculty of Health Sciences, Universiti Sultan Zainal Abidin, Terengganu, Malaysia
| | - H. Iwase
- Department of Accelerator Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Japan
- Department of Accelerator Science, Graduate University for Advanced Studies(SOKENDAI), Tsukuba, Ibaraki, Japan
| | - M. Musarudin
- School of Health Sciences, Health Campus, Universiti Sains Malaysia, Kubang Kerian, Kelantan
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Radioactivity induced in new-generation cardiac implantable electronic devices during high-energy X-ray irradiation. Appl Radiat Isot 2020; 163:109206. [DOI: 10.1016/j.apradiso.2020.109206] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Revised: 03/27/2020] [Accepted: 04/24/2020] [Indexed: 01/17/2023]
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Yani S, Budiansah I, Rhani MF, Haryanto F. Monte carlo model and output factors of elekta infinity™ 6 and 10 MV photon beam. Rep Pract Oncol Radiother 2020; 25:470-478. [PMID: 32494222 DOI: 10.1016/j.rpor.2020.03.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 02/02/2020] [Accepted: 03/20/2020] [Indexed: 10/24/2022] Open
Abstract
Aim This study aimed to commission the Elekta Infinity™ working in 6 and 10 MV photon beam installed in Concord International Hospital, Singapore, and compare the OFs between MC simulation and measurement using PTW semiflex and microDiamond detector for small field sizes. Material and Methods There are two main steps in this study: modelling of Linac 6 and 10 MV photon beam and analysis of the output factors for field size 2 × 2-10 × 10 cm2. The EGSnrc/BEAMnrc-DOSXYZnrc code was used to model and characterize the Linac and to calculate the dose distributions in a water phantom. The dose distribution and OFs were compared to the measurement data in the same condition. Results The commissioning process was only conducted for a 10 × 10 cm2 field size. The PDD obtained from MC simulation showed a good agreement with the measurement. The local dose difference of PDDs was less than 2% for 6 and 10 MV. The initial electron energy was 5.2 and 9.4 MeV for 6 and 10 MV photon beam, respectively. This Linac model can be used for dose calculation in other situations and different field sizes because this Linac has been commissioned and validated using Monte Carlo simulation. The 10 MV Linac produces higher electron contamination than that of 6 MV. Conclusions The Linac model in this study was acceptable. The most important result in this work comes from OFs resulted from MC calculation. This value was more significant than the OFs from measurement using semiflex and microDiamond for all beam energy and field sizes because of the CPE phenomenon.
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Affiliation(s)
- Sitti Yani
- Department of Physics, Faculty of Mathematics and Natural Sciences, IPB University (Bogor Agricultural University), Babakan, Bogor, Indonesia.,Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesa 10, Bandung, Indonesia
| | - Indra Budiansah
- Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesa 10, Bandung, Indonesia
| | | | - Freddy Haryanto
- Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesa 10, Bandung, Indonesia
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Tajiki S, Nedaie HA, Rahmani F. A Monte Carlo study of neutron contamination in presence of circular cones during stereotactic radiotherapy with 18 MV photon beams. Biomed Phys Eng Express 2020; 6:035016. [PMID: 33438661 DOI: 10.1088/2057-1976/ab7ff2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
High-energy photons are being used to treat different kinds of cancer, but it may increase the rate of secondary cancers due to the neutron contamination as well as over exposing of patients and medical staffs in radiation therapy Takam, Bezak, Marcu, and Yeoh, 2011, Radiation Research, 176, 508-520. Due to some difficulties in experimental measurements of neutron contamination, Monte Carlo method is an efficient tool to investigate dose parameters and characteristics in new techniques. The 18-MV photon beam of linac and circular cones have been simulated by MCNP5 code. Various parameters of photon and neutron including mean energy, flux, KERMA, the number of particles crossing a surface at a distance of 100 cm (SSD = 100 cm) as well as the change in photon and neutron spectrum as well as in intensity through the transmission in the circular collimators have been investigated. The results of this study show that the use of a circular collimator decreases neutron dose in the central axis, which is an advantage, but neutron contamination inducing small neutron dose is distributed all over the space. On the surface of phantom, photon dose rate is approximately equal to 3.41E7 (mGy/mA.min) for different collimators, but the neutron dose rate is 1.64E2 (mGy/ mA.min), 2.03E2 (mGy/ mA.min) and 2.52E2 (mGy/mA.min) for diameters of 12, 20 and 40 mm, respectively and it decreases by decreasing the diameter of the collimator. The neutron dose rate decreases from 9.68E7 and 9.74E7 (mGy/min.mA) for open field size 33 cm2 and 55 cm2 to 1.64E2 (mGy/min.mA), 2.02E2 (mGy/min.mA) and 2.52E2 (mGy/min.mA) for collimator diameter of 12 mm, 20 mm and 40 mm. It can be concluded that the use of circular collimators has an advantage of reducing neutron dose in the central axis. It should be mentioned that the off-axis neutron dose surrounding the collimator can be eliminated using an external neutron shield without perturbing the treatment field.
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Affiliation(s)
- Sareh Tajiki
- Department of Medical Physics and Biomedical Engineering, Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran. Radiotherapy Oncology Research Center, Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran
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