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Medeiros MPC, Silva AX, Rebello WF, Santos RFG, Stenders RM, Braz D, Braga KL, Thalhofer JL, Berdeguez MBT, Andrade ER. Shielding implications on secondary radiation doses in prostate cancer treatment. Appl Radiat Isot 2020; 163:109163. [PMID: 32561036 DOI: 10.1016/j.apradiso.2020.109163] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 03/16/2020] [Accepted: 03/26/2020] [Indexed: 11/29/2022]
Abstract
Medical linear accelerators (linacs) require a physical structure designed to provide adequate structural support which ensures the safety of patients, operators and the general public. During a radiotherapy session, healthy tissues are exposed to radiation, even with these safety guarantees. This unwanted exposure may increase the likelihood of developing secondary cancer. This work uses the MCNP-5 code to computationally simulate a conformational 3D radiotherapy protocol for prostate cancer. Also, it investigates the potential effects of radiotherapy room shielding composition on equivalent and effective doses in the patient's body. A computational model of an actual room was developed considering a Varian Trilogy linac operating at 10 MeV. This model enabled dose calculations for an anthropomorphic phantom called REX to be performed. This phantom has sufficient details of all relevant organs and tissues needed to estimate the effective dose of the patient. The treatment protocol modeled in this study came from the database of patients treated by the Brazilian National Cancer Institute (Inca). For this protocol, the total dose to be applied to the patient is equally distributed over the four gantry inclination angles (0°, 90°, 180° and 270°). The simulated results suggested that the equivalent dose on different organs and tissues has been increased by concrete shielding. Regarding the effective dose due to the presence of additional shielding (steel or lead), the simulation suggests that such variations can be considered small. Overall the results allowed quantifying the specific contribution of concrete, lead, and steel as part of shielding on the equivalent and effective doses in the patient.
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Affiliation(s)
- Marcos P C Medeiros
- Nuclear Engineering Graduate Program, Federal University of Rio de Janeiro (COPPE/UFRJ), Rio de Janeiro, Brazil; Nuclear Engineering Graduate Program, Military Institute of Engineering (IME), Rio de Janeiro, Brazil.
| | - Ademir X Silva
- Nuclear Engineering Graduate Program, Federal University of Rio de Janeiro (COPPE/UFRJ), Rio de Janeiro, Brazil.
| | - Wilson F Rebello
- State University of Rio de Janeiro, Faculty of Engineering and IBRAG, Rio de Janeiro, Brazil.
| | - Raphael F G Santos
- Nuclear Engineering Graduate Program, Federal University of Rio de Janeiro (COPPE/UFRJ), Rio de Janeiro, Brazil.
| | - Ricardo M Stenders
- IBMEC, Faculty of Engineering, Graduate Program, Rio de Janeiro, Brazil.
| | - Delson Braz
- Nuclear Engineering Graduate Program, Federal University of Rio de Janeiro (COPPE/UFRJ), Rio de Janeiro, Brazil.
| | - Kelmo L Braga
- Nuclear Engineering Graduate Program, Federal University of Rio de Janeiro (COPPE/UFRJ), Rio de Janeiro, Brazil.
| | - Jardel L Thalhofer
- Nuclear Engineering Graduate Program, Federal University of Rio de Janeiro (COPPE/UFRJ), Rio de Janeiro, Brazil.
| | - Mirta B T Berdeguez
- Nuclear Engineering Graduate Program, Federal University of Rio de Janeiro (COPPE/UFRJ), Rio de Janeiro, Brazil.
| | - Edson R Andrade
- Nuclear Engineering Graduate Program, Federal University of Rio de Janeiro (COPPE/UFRJ), Rio de Janeiro, Brazil; Defense Engineering Graduate Program, Military Institute of Engineering (IME), Rio de Janeiro, Brazil.
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Effect of external shielding for neutrons during radiotherapy for prostate cancer, considering the 2300 CD linear accelerator and voxel phantom. Radiat Phys Chem Oxf Engl 1993 2014. [DOI: 10.1016/j.radphyschem.2013.02.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Ho L, White P, Chan E, Chan K, Ng J, Tam T. Evaluation of Optimum Room Entry Times for Radiation Therapists after High Energy Whole Pelvic Photon Treatments. J Occup Health 2012; 54:131-40. [DOI: 10.1539/joh.11-0161-fs] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Lavine Ho
- Department of Health Technology and InformaticsThe Hong Kong Polytechnic UniversityHong Kong
| | - Peter White
- Department of Health Technology and InformaticsThe Hong Kong Polytechnic UniversityHong Kong
| | - Edward Chan
- Department of Health Technology and InformaticsThe Hong Kong Polytechnic UniversityHong Kong
| | - Kim Chan
- Department of Health Technology and InformaticsThe Hong Kong Polytechnic UniversityHong Kong
| | - Janet Ng
- Department of Health Technology and InformaticsThe Hong Kong Polytechnic UniversityHong Kong
| | - Timothy Tam
- Department of Health Technology and InformaticsThe Hong Kong Polytechnic UniversityHong Kong
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Takam R, Bezak E, Marcu LG, Yeoh E. Out-of-Field Neutron and Leakage Photon Exposures and the Associated Risk of Second Cancers in High-Energy Photon Radiotherapy: Current Status. Radiat Res 2011; 176:508-20. [DOI: 10.1667/rr2606.1] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Kry SF, Johnson JL, White RA, Howell RM, Kudchadker RJ, Gillin MT. Neutron-induced electronic failures around a high-energy linear accelerator. Med Phys 2010; 38:34-9. [DOI: 10.1118/1.3519905] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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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.
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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
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Rebello W, Silva A, Facure A, Roque H. Monte Carlo simulation of photoneutrons streaming inside radiotherapy treatment rooms as a function of gantry angles. PROGRESS IN NUCLEAR ENERGY 2010. [DOI: 10.1016/j.pnucene.2009.07.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Mesbahi A, Keshtkar A, Mohammadi E, Mohammadzadeh M. Effect of wedge filter and field size on photoneutron dose equivalent for an 18MV photon beam of a medical linear accelerator. Appl Radiat Isot 2010; 68:84-9. [DOI: 10.1016/j.apradiso.2009.08.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2009] [Revised: 08/15/2009] [Accepted: 08/17/2009] [Indexed: 11/30/2022]
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