Boron concentration measurement in biological tissues by charged particle spectrometry

Measurement of boron concentration in biological
tissues is a fundamental aspect of boron neutron
capture therapy, because the outcome of the therapy
depends on the distribution of boron at a cellular level,
besides on its overall concentration. This work describes a
measurement technique based on the spectroscopy of the
charged particles emitted in the reaction 10B(n,a)7Li
induced by thermal neutrons, allowing for a quantitative
determination of the boron concentration in the different
components that may be simultaneously present in a tissue
sample, such as healthy cells, tumor cells and necrotic
cells. Thin sections of tissue containing 10B are cut at low
temperatures and irradiated under vacuum in a thermal
neutron field. The charged particles arising from the sample
during the irradiation are collected by a thin silicon
detector, and their spectrum is used to determine boron
concentration through relatively easy calculations. The
advantages and disadvantages of this technique are here
described, and validation of the method using tissue standards
with known boron concentrations is present