A design study for an accelerator-based epithermal neutron beam for BNCT.
An achievable design concept for a boron neutron capture therapy (BNCT) facility, based on a high-current, low-energy proton accelerator, is described. Neutrons are produced within a thick natural lithium target, under bombardment from protons with an initial energy between 2.5 and 3.0 MeV. The proton current will be up to 10 mA. After gamma-ray filtering, the neutrons are partially moderated to epithermal energies within a heavy-water moderator, poisoned with 6Li to remove thermal neutrons. Monte Carlo modelling has been used to predict system performance in terms of neutron fluence rate and neutron and gamma-ray dose at the patient position. The relationship between the system performance and key parameters, such as proton energy, moderator depth and 6Li concentration, has been investigated. With a proton current of 10 mA, the facility is capable of providing a therapy beam with a useful neutron fluence rate of 10(9) cm-2 s-1 and a neutron dose per unit fluence of less than 6 x 10(-13) Gy cm2, with a gamma-ray contamination of the therapy beam of about 10(-13) Gy cm2.
Allen
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School of Physics and Space Research, University of Birmingham, Edgbaston, UK.
Beynon
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D055592:Biophysical Phenomena; D001703:Biophysics; D016754:Boron Neutron Capture Therapy / Q000295:instrumentation*; D004867:Equipment Design; D005214:Fast Neutrons; D006801:Humans; D008954:Models, Biological; D009010:Monte Carlo Method; D009369:Neoplasms / Q000532:radiotherapy; D010315:Particle Accelerators / Q000295:instrumentation*; D011522:Protons; D011880:Radiotherapy Planning, Computer-Assisted
D011522:Protons