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Neutron/photon physics investigation of brain tumor treatments with BNCT
Author(s) -
Ye SungJoon
Publication year - 1998
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 - 10.1118/1.598283
Subject(s) - neutron capture , neutron , nuclear medicine , dosimetry , neutron temperature , neutron source , materials science , irradiation , fluence , relative biological effectiveness , radiochemistry , monte carlo method , nuclear physics , physics , medicine , chemistry , mathematics , statistics
In boron neutron capture therapy (BNCT) for brain tumor treatments, a computational method to calculate the tumor cell survival probability versus treatment conditions is developed as a preclinical neutron beam evaluation. A treatment condition is characterized by the spectrum and lateral size of neutron beams, single or bilateral exposure, and the choice of boron carrier drugs (BPA‐F and BSH). The radiation transport from the neutron source to tumors is carried out using Monte Carlo methods: (1) reactor‐based BNCT facility modeling to yield the neutron spectra at an irradiation port; (2) dosimetry to limit the neutron fluence below a tolerance dose (10.5 Gy Eq); (3) calculation of the10 B ( n , α ) 7 Li reaction density in tumors. Finally, from a cell‐killing yield per ( n , α ) reaction, the cell survival probability distribution across the tumor is calculated for various treatment conditions. A shallow surface tumor could be effectively treated by single exposure with the volume‐averaged cell survival probability of 10 − 3– 10− 5, while a deep tumor will require bilateral exposure to avoid a high cell survival at depth. With pure epithermal beams eliminating low‐ and high‐energy neutrons, the cell survival can be decreased by factors of 2–10, compared to the unmodified neutron spectrum.