Designing accelerator-based epithermal neutron beams for boron neutron capture therapy

Authors:   Bleuel D.L., Donahue R.J., Ludewigt B.A., Vujic J.
Journal: Medical Physics
https://doi.org/10.1118/1.598353
Abstract: The reaction has been investigated as an accelerator?driven neutron source for proton energies between 2.1 and 2.6 MeV. Epithermal neutron beams shaped by three moderator materials, and have been analyzed and their usefulness for boron neutron capture therapy (BNCT) treatments evaluated. Radiation transport through the moderator assembly has been simulated with the Monte Carlo N?particle code (MCNP). Fluence and dose distributions in a head phantom were calculated using BNCT treatment planning software. Depth?dose distributions and treatment times were studied as a function of proton beam energy and moderator thickness. It was found that an accelerator?based neutron source with or as moderator material can produce depth?dose distributions superior to those calculated for a previously published neutron beam design for the Brookhaven Medical Research Reactor, achieving up to ?50% higher doses near the midline of the brain. For a single beam treatment, a proton beam current of 20 mA, and a moderator, the treatment time was estimated to be about 40 min. The tumor dose deposited at a depth of 8 cm was calculated to be about 21 Gy?Eq.