Highlights
- •Reducing the epithermal neutron energy to increase treatement efficiency.
- •Therapeutic Gain higher for 1 keV neutrons compared to 10 keV neutrons in non-superficials tumours cases.
- •New dose calculation method explicited, classifying dose component by reaction type.
Abstract
Background and purpose: Accelerator-Based Boron Neutron Capture Therapy is a radiotherapy
based on compact accelerator neutron sources requiring an epithermal neutron field
for tumour irradiations. Neutrons of 10 keV are considered as the maximum optimised
energy to treat deep-seated tumours. We investigated, by means of Monte Carlo simulations,
the epithermal range from 10 eV to 10 keV in order to optimise the maximum epithermal
neutron energy as a function of the tumour depth.
Methods: A Snyder head phantom was simulated and mono-energetic neutrons with 4 different
incident energies were used: 10 eV, 100 eV, 1 keV and 10 keV. 10B capture rates and absorbed dose composition on every tissue were calculated to describe
and compare the effects of lowering the maximum epithermal energy. The Therapeutic
Gain (TG) was estimated considering the whole brain volume.
Results: For tumours seated at 4 cm depth, 10 eV, 100 eV and 1 keV neutrons provided
respectively 54%, 36% and 18% increase on the TG compared to 10 keV neutrons. Neutrons
with energies between 10 eV and 1 keV provided higher TG than 10 keV neutrons for
tumours seated up to 6.4 cm depth inside the head. The size of the tumour does not
change these results.
Conclusions: Using lower epithermal energy neutrons for AB-BNCT tumour irradiation
could improve treatment efficacy, delivering more therapeutic dose while reducing
the dose in healthy tissues. This could lead to new Beam Shape Assembly designs in
order to optimise the BNCT irradiation.
Keywords
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Article info
Publication history
Published online: July 12, 2021
Accepted:
June 20,
2021
Received in revised form:
June 1,
2021
Received:
March 2,
2020
Identification
Copyright
© 2021 Published by Elsevier Ltd on behalf of Associazione Italiana di Fisica Medica.
