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Hiraga F. Effects of neutron sources and moderator materials on therapeutic dose delivery to deep-seated lesions in proton accelerator-based boron neutron capture therapy. Appl Radiat Isot 2024; 210:111359. [PMID: 38772121 DOI: 10.1016/j.apradiso.2024.111359] [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: 06/28/2022] [Revised: 04/26/2024] [Accepted: 05/14/2024] [Indexed: 05/23/2024]
Abstract
This study aimed to identify the optimal conditions for delivering sufficient doses to deep-seated lesions within short irradiation times for two boron carriers of different T/N ratios. The therapeutic depth and irradiation time of a neutron beam for beam shaping assemblies (BSAs) with a Li or Be target and a MgF2 or CaF2 moderator were examined with the fast-neutron dose per epithermal neutron (FNR) as a parameter. When T/N = 3.61, the therapeutic depth was almost saturated at an FNR of about 10 × 10-13 Gy cm2; when the FNR value was about 10 × 10-13 Gy cm2, the therapeutic depth of the neutron beam for the BSA with a Be target and a MgF2 moderator was almost identical to that for the neutron beam for the BSA with a Be target and a CaF2 moderator, and slightly greater than those for the neutron beams for the BSAs with a Li target and a MgF2 or CaF2 moderator; moreover, the irradiation time of the neutron beam for the BSA with a Be target and a MgF2 moderator was shorter than that for the neutron beam for the BSA with a Be target and a CaF2 moderator. When T/N = 100, the therapeutic depths of the neutron beams for the BSAs varied greatly depending on the FNR, and were greater than the corresponding values for T/N = 3.61. We therefore concluded that the BSA with a Be target and a MgF2 moderator that produced a neutron beam with an FNR of about 10 × 10-13 Gy cm2 is optimal for delivering sufficient doses to deep-seated lesions in short irradiation times when T/N = 3.61, and stricter control over FNR is required when T/N = 100.
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Affiliation(s)
- F Hiraga
- Hokkaido University Faculty of Engineering, Kita-13, Nishi-8, Kita-ku, Sapporo, Hokkaido, 060-8628, Japan.
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Hiraga F, Ooie T. Synergistic effects of fast-neutron dose per epithermal neutron and 10B concentration on relative-biological-effectiveness dose for accelerator-based boron neutron capture therapy. Appl Radiat Isot 2019; 144:1-4. [PMID: 30465991 DOI: 10.1016/j.apradiso.2018.11.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 02/06/2018] [Accepted: 11/10/2018] [Indexed: 11/25/2022]
Abstract
The efficacy of accelerator-based boron neutron capture therapy was examined through relative-biological-effectiveness dose calculations with the fast-neutron dose per epithermal neutron (FNR) and the 10B concentration as parameters. In the case of a tumor 10B concentration of 65 ppm, the treatment efficacy depended more strongly on the FNR when the normal-tissue 10B concentration was 0.65 ppm, which would be brought about by the administration of an advanced chemical compound, than when the 10B concentration was 18 ppm, which is attainable by the use of boronophenylalanine.
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Affiliation(s)
- F Hiraga
- Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan.
| | - T Ooie
- Graduate school of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan.
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Khorshidi A. Exploration of Adiabatic Resonance Crossing Through Neutron Activator Design for Thermal and Epithermal Neutron Formation in 99Mo Production and BNCT Applications. Cancer Biother Radiopharm 2015; 30:317-29. [DOI: 10.1089/cbr.2014.1734] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Abdollah Khorshidi
- Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran
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Inoue R, Hiraga F, Kiyanagi Y. Optimum design of a moderator system based on dose calculation for an accelerator driven Boron Neutron Capture Therapy. Appl Radiat Isot 2014; 88:225-8. [DOI: 10.1016/j.apradiso.2013.12.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 12/16/2013] [Accepted: 12/17/2013] [Indexed: 11/17/2022]
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Tanaka K, Endo S, Yonai S, Baba M, Hoshi M. A TPD and AR based comparison of accelerator neutron irradiation fields between (7)Li and W targets for BNCT. Appl Radiat Isot 2013; 88:229-32. [PMID: 24359788 DOI: 10.1016/j.apradiso.2013.11.098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 11/22/2013] [Accepted: 11/23/2013] [Indexed: 11/28/2022]
Abstract
The characteristics of moderator assembly dimension was investigated for the usage of (7)Li(p,n) neutrons by 2.3-2.8MeV protons and W(p,n) neutrons by 50MeV protons. The indexes were the treatable protocol depth (TPD) and advantage depth (AD). Consequently, a configuration for W target with the Fe filter, Fluental moderator, Pb reflector showed the TPD of 5.8cm and AD of 9.3cm. Comparable indexes were found for the Li target in a geometry with the MgF2 moderator and Teflon reflector.
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Affiliation(s)
- Kenichi Tanaka
- Center of Medical Education, Sapporo Medical University, Sapporo, Japan.
| | - Satoru Endo
- Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima, Japan
| | - Shunsuke Yonai
- Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Japan
| | - Mamoru Baba
- Cyclotron Radioisotope Center, Tohoku University, Miyagi, Japan
| | - Masaharu Hoshi
- Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima 734-8553, Japan
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TAKATA T, TANAKA H, SAKURAI Y, MARUHASHI A. Increase in Irradiation Beam Intensity by Using a Hybrid Target System in Cyclotron-Based Neutron Capture Therapy. J NUCL SCI TECHNOL 2010. [DOI: 10.1080/18811248.2010.9720954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Kim JK, Kim KO. CURRENT RESEARCH ON ACCELERATOR-BASED BORON NEUTRON CAPTURE THERAPY IN KOREA. NUCLEAR ENGINEERING AND TECHNOLOGY 2009. [DOI: 10.5516/net.2009.41.4.531] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Tanaka H, Sakurai Y, Suzuki M, Takata T, Masunaga S, Kinashi Y, Kashino G, Liu Y, Mitsumoto T, Yajima S, Tsutsui H, Takada M, Maruhashi A, Ono K. Improvement of dose distribution in phantom by using epithermal neutron source based on the Be(p,n) reaction using a 30 MeV proton cyclotron accelerator. Appl Radiat Isot 2009; 67:S258-61. [PMID: 19376720 DOI: 10.1016/j.apradiso.2009.03.096] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
In order to generate epithermal neutrons for boron neutron capture therapy (BNCT), we proposed the method of filtering and moderating fast neutrons, which are emitted from the reaction between a beryllium target and 30 MeV protons accelerated by a cyclotron, using an optimum moderator system composed of iron, lead, aluminum, calcium fluoride, and enriched (6)LiF ceramic filter. At present, the epithermal-neutron source is under construction since June 2008 at Kyoto University Research Reactor Institute. This system consists of a cyclotron to supply a proton beam of about 1 mA at 30 MeV, a beam transport system, a beam scanner system for heat reduction on the beryllium target, a target cooling system, a beam shaping assembly, and an irradiation bed for patients. In this article, an overview of the cyclotron-based neutron source (CBNS) and the properties of the treatment neutron beam optimized by using the MCNPX Monte Carlo code are presented. The distribution of the RBE (relative biological effectiveness) dose in a phantom shows that, assuming a (10)B concentration of 13 ppm for normal tissue, this beam could be employed to treat a patient with an irradiation time less than 30 min and a dose less than 12.5 Gy-eq to normal tissue. The CBNS might be an alternative to the reactor-based neutron sources for BNCT treatments.
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Affiliation(s)
- H Tanaka
- Research Reactor Institute, Kyoto University, Asashiro-nishi 2-1010, Kumatori-cho, Osaka 590-0494, Japan.
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Tanaka K, Yokobori H, Endo S, Kobayashi T, Bengua G, Saruyama I, Nakagawa Y, Hoshi M. Characteristics of proton beam scanning dependent on Li target thickness from the viewpoint of heat removal and material strength for accelerator-based BNCT. Appl Radiat Isot 2008; 67:259-65. [PMID: 19042135 DOI: 10.1016/j.apradiso.2008.10.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2007] [Revised: 09/18/2008] [Accepted: 10/02/2008] [Indexed: 11/24/2022]
Abstract
This study demonstrates the characterization of proton spot scanning on a Li target assembly for accelerator-based BNCT from the viewpoint of heat removal and material strength. These characteristics are investigated as to their dependence on the Li target thickness, considering that the Cu backing plate has more suitable heat removal properties than Li. Two situations are considered in this paper, i.e. the cyclic operation of the spot scanning, and a stalled spot scanning cycle where the proton beam stays focused on a single position on the Li target. It was found that the maximum of the Li temperature and the strain of the Cu backing increase as the cycle period increases. A cycle period less than 120 ms (over 8.3 Hz of frequency) enables the Li temperature to be kept below 150 degrees C and a cycle of less than 115 ms (8.7 Hz) keeps the Cu strain below the critical value for a 230 microm thick Li target, though the values are evaluated conservatively. Against expectation, the Li temperature and Cu strain are larger for a 100 microm thick target than for a 230 microm target. The required cycle period in this case is 23 ms (43 Hz) for maintaining a reasonable Li temperature and 9 ms (110 Hz) to prevent Cu fatigue fracture. For a stall in the spot scanning cycle, the Cu temperature increases as the beam shutdown time increases. The time for Cu to reach its melting point is estimated to be 4.2 ms at the surface, 20 ms at 1mm depth, for both of 100 and 230 microm thick targets. At least 34 ms is estimated to be enough to make a hole on Cu backing plate. A beam shutdown mechanism with a response time of about 20 ms is therefore required.
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Affiliation(s)
- Kenichi Tanaka
- Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan.
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YONAI S, BABA M, NAKAMURA T, YOKOBORI H, TAHARA Y. Extension of Spallation-Based BNCT Concept to Medium- to High-Energy Accelerators. J NUCL SCI TECHNOL 2008. [DOI: 10.1080/18811248.2008.9711447] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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YONAI S, BABA M, ITOGA T, NAKAMURA T, YOKOBORI H, TAHARA Y. Influences of Neutron Source Spectrum and Thermal Neutron Scattering Law Data on the MCNPX Simulation of a Cyclotron-Based Neutron Field for Boron Neutron Capture Therapy. J NUCL SCI TECHNOL 2007. [DOI: 10.1080/18811248.2007.9711383] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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TAHARA Y, ODA Y, SHIRAKI T, TSUTSUI T, YOKOBORI H, YONAI S, BABA M, NAKAMURA T. Engineering Design of a Spallation Reaction-Based Neutron Generator for Boron Neutron Capture Therapy. J NUCL SCI TECHNOL 2006. [DOI: 10.1080/18811248.2006.9711063] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Yonai S, Itoga T, Baba M, Nakamura T, Yokobori H, Tahara Y. Benchmark experiments for cyclotron-based neutron source for BNCT. Appl Radiat Isot 2004; 61:997-1001. [PMID: 15308182 DOI: 10.1016/j.apradiso.2004.05.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In the previous study, we found the feasibility of a cyclotron-based BNCT using the Ta(p,n) neutrons at 90 degrees bombarded by 50 MeV protons, and the iron, AlF(3), Al and (6)LiF moderators by simulations using the MCNPX code. In order to validate the simulations to realize the cyclotron-based BNCT, we measured the epithermal neutron energy spectrum passing through the moderators with our new spectrometer consisting of a (3)He gas counter covered with a silicon rubber loaded with (nat)B and polyethylene moderator and the depth distribution of the reaction rates of (197)Au(n,gamma)(198)Au in an acrylic phantom set behind the rear surface of the moderators. The measured results were compared with the calculations using the MCNPX code. We obtained the good agreement between the calculations and measurements within approximately 10% for the neutron energy spectra and within approximately 20% for the depth distribution of the reaction rates of (197)Au(n,gamma)(198)Au in the phantom. The comparison clarified a good accuracy of the calculation of the neutron energy spectrum passing through the moderator and the thermalization in a phantom. These experimental results will be a good benchmark data to evaluate the accuracy of the calculation code.
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Affiliation(s)
- S Yonai
- Cyclotron and Radioisotope Center, Tohoku University, Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan.
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