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An accelerator‐based epithermal photoneutron source for boron neutron capture therapy
Author(s) -
Mitchell Hannah E.
Publication year - 1997
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.598140
Subject(s) - neutron capture , neutron , neutron source , nuclear physics , neutron temperature , beryllium , linear particle accelerator , particle accelerator , nuclear engineering , materials science , beam (structure) , radiochemistry , physics , chemistry , optics , engineering
Boron neutron capture therapy is an experimental cancer radiotherapy modality in which a boronated pharmaceutical that preferentially accumulates in malignant tissue is administered, followed by exposure of the tissue in the treatment volume to a thermal neutron field. Presently in the US and Europe, for treatment of deeper‐seated tumors, an epithermal beam is felt preferable in generating the necessary thermal neutron field. Boronated cells are selectively destroyed via energy deposition resulting from the10 B ( n , α ) 7 Li interaction. Current usable beams are reactor‐based; a viable alternative is production of the epithermal neutron beam using an accelerator. Various proposed accelerator‐based designs exist, most based on proton beams with beryllium or lithium targets. This dissertation examines the efficacy of a novel approach incorporating an electron linear accelerator (4 to 8 MeV) in the production of a photoneutron source, which may help to resolve present concerns associated with some accelerator‐based sources, including target cooling. A conceptual design to produce epithermal photoneutrons, with high energy bremsstrahlung on deuterium targets, is presented along with computational and experimental neutron production data. A clinically acceptable epithermal neutron flux on the order of 10 7neutrons/second per milliampere of electron current is shown obtainable. Additionally, the neutron beam is modified and characterized, employing two unique moderating materials (anAl / AlF 3composite and a stacked Al/Teflon design).