Effects of neutron sources and moderator materials on therapeutic dose delivery to deep-seated lesions in proton accelerator-based boron neutron capture therapy.

Autor: Hiraga F; Hokkaido University Faculty of Engineering, Kita-13, Nishi-8, Kita-ku, Sapporo, Hokkaido, 060-8628, Japan. Electronic address: hiraga@eng.hokudai.ac.jp.
Jazyk: angličtina
Zdroj: Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine [Appl Radiat Isot] 2024 Aug; Vol. 210, pp. 111359. Date of Electronic Publication: 2024 May 15.
DOI: 10.1016/j.apradiso.2024.111359
Abstrakt: 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 MgF 2 or CaF 2 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 cm 2 ; when the FNR value was about 10 × 10 -13  Gy cm 2 , the therapeutic depth of the neutron beam for the BSA with a Be target and a MgF 2 moderator was almost identical to that for the neutron beam for the BSA with a Be target and a CaF 2 moderator, and slightly greater than those for the neutron beams for the BSAs with a Li target and a MgF 2 or CaF 2 moderator; moreover, the irradiation time of the neutron beam for the BSA with a Be target and a MgF 2 moderator was shorter than that for the neutron beam for the BSA with a Be target and a CaF 2 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 MgF 2 moderator that produced a neutron beam with an FNR of about 10 × 10 -13  Gy cm 2 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.
Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Fujio HIRAGA reports financial support was provided by Japan Society for the Promotion of Science.
(Copyright © 2024 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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