skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Characterization of moderator assembly dimension for accelerator boron neutron capture therapy of brain tumors using {sup 7}Li(p,n) neutrons at proton energy of 2.5 MeV

Abstract

The characteristics of moderator assembly dimension are investigated for the usage of {sup 7}Li(p,n) neutrons by 2.5 MeV protons in boron newtron capture therapy (BNCT) of brain tumors in the present study. The indexes checked are treatable protocol depth (TPD), which is the greatest depth of the region satisfying the dose requirements in BNCT protocol, proton current necessary to complete BNCT by 1 h irradiation, and the heat flux deposited in the Li target which should be removed. Assumed materials are D{sub 2}O for moderator, and mixture of polyethylene and LiF with 50 wt % for collimator. Dose distributions have been computed with MCNP 4B and 4C codes. Consequently, realized TPD does not show a monotonical tendency for the Li target diameter. However, the necessary proton current and heat flux in the Li target decreases as the Li target diameter increases, while this trend reverses at around 10 cm of the Li target diameter for the necessary proton current in the condition of this study. As to the moderator diameter, TPD does not exhibit an apparent dependence. On the other hand, necessary proton current and heat flux decrease as the moderator diameter increases, and this tendency saturates at around 60more » cm of the moderator diameter in this study. As to the collimator, increase in inner diameter is suitable from the viewpoint of increasing TPD and decreasing necessary proton current and heat flux, while these indexes do not show apparent difference for collimator inner diameters over 14 cm for the parameters treated here. The practical viewpoint in selecting the parameters of moderator assembly dimension is to increase TPD, within the technically possible condition of accelerated proton current and heat removal from the Li target. In this process, the values for which the resultant characteristics mentioned above saturate or reverse would be important factors.« less

Authors:
; ; ; ; ;  [1]
  1. Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi-Minami-ku, Hiroshima, 834-8553 (Japan)
Publication Date:
OSTI Identifier:
20853182
Resource Type:
Journal Article
Journal Name:
Medical Physics
Additional Journal Information:
Journal Volume: 33; Journal Issue: 6; Other Information: DOI: 10.1118/1.2199596; (c) 2006 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-2405
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; ACCELERATORS; BORON; BRAIN; COLLIMATORS; DOSIMETRY; HEAT FLUX; LITHIUM 7; LITHIUM FLUORIDES; NEOPLASMS; NEUTRON CAPTURE THERAPY; POLYETHYLENES; PROTON BEAMS; RADIATION DOSE DISTRIBUTIONS

Citation Formats

Tanaka, Kenichi, Kobayashi, Tooru, Bengua, Gerard, Nakagawa, Yoshinobu, Endo, Satoru, Hoshi, Masaharu, Kyoto University Research Reactor Institute, Kyoto, National Kagawa Children's Hospital, Zentsuji, and Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi-Minami-ku, Hiroshima, 834-8553. Characterization of moderator assembly dimension for accelerator boron neutron capture therapy of brain tumors using {sup 7}Li(p,n) neutrons at proton energy of 2.5 MeV. United States: N. p., 2006. Web. doi:10.1118/1.2199596.
Tanaka, Kenichi, Kobayashi, Tooru, Bengua, Gerard, Nakagawa, Yoshinobu, Endo, Satoru, Hoshi, Masaharu, Kyoto University Research Reactor Institute, Kyoto, National Kagawa Children's Hospital, Zentsuji, & Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi-Minami-ku, Hiroshima, 834-8553. Characterization of moderator assembly dimension for accelerator boron neutron capture therapy of brain tumors using {sup 7}Li(p,n) neutrons at proton energy of 2.5 MeV. United States. https://doi.org/10.1118/1.2199596
Tanaka, Kenichi, Kobayashi, Tooru, Bengua, Gerard, Nakagawa, Yoshinobu, Endo, Satoru, Hoshi, Masaharu, Kyoto University Research Reactor Institute, Kyoto, National Kagawa Children's Hospital, Zentsuji, and Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi-Minami-ku, Hiroshima, 834-8553. 2006. "Characterization of moderator assembly dimension for accelerator boron neutron capture therapy of brain tumors using {sup 7}Li(p,n) neutrons at proton energy of 2.5 MeV". United States. https://doi.org/10.1118/1.2199596.
@article{osti_20853182,
title = {Characterization of moderator assembly dimension for accelerator boron neutron capture therapy of brain tumors using {sup 7}Li(p,n) neutrons at proton energy of 2.5 MeV},
author = {Tanaka, Kenichi and Kobayashi, Tooru and Bengua, Gerard and Nakagawa, Yoshinobu and Endo, Satoru and Hoshi, Masaharu and Kyoto University Research Reactor Institute, Kyoto and National Kagawa Children's Hospital, Zentsuji and Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi-Minami-ku, Hiroshima, 834-8553},
abstractNote = {The characteristics of moderator assembly dimension are investigated for the usage of {sup 7}Li(p,n) neutrons by 2.5 MeV protons in boron newtron capture therapy (BNCT) of brain tumors in the present study. The indexes checked are treatable protocol depth (TPD), which is the greatest depth of the region satisfying the dose requirements in BNCT protocol, proton current necessary to complete BNCT by 1 h irradiation, and the heat flux deposited in the Li target which should be removed. Assumed materials are D{sub 2}O for moderator, and mixture of polyethylene and LiF with 50 wt % for collimator. Dose distributions have been computed with MCNP 4B and 4C codes. Consequently, realized TPD does not show a monotonical tendency for the Li target diameter. However, the necessary proton current and heat flux in the Li target decreases as the Li target diameter increases, while this trend reverses at around 10 cm of the Li target diameter for the necessary proton current in the condition of this study. As to the moderator diameter, TPD does not exhibit an apparent dependence. On the other hand, necessary proton current and heat flux decrease as the moderator diameter increases, and this tendency saturates at around 60 cm of the moderator diameter in this study. As to the collimator, increase in inner diameter is suitable from the viewpoint of increasing TPD and decreasing necessary proton current and heat flux, while these indexes do not show apparent difference for collimator inner diameters over 14 cm for the parameters treated here. The practical viewpoint in selecting the parameters of moderator assembly dimension is to increase TPD, within the technically possible condition of accelerated proton current and heat removal from the Li target. In this process, the values for which the resultant characteristics mentioned above saturate or reverse would be important factors.},
doi = {10.1118/1.2199596},
url = {https://www.osti.gov/biblio/20853182}, journal = {Medical Physics},
issn = {0094-2405},
number = 6,
volume = 33,
place = {United States},
year = {Thu Jun 15 00:00:00 EDT 2006},
month = {Thu Jun 15 00:00:00 EDT 2006}
}