title: Filter, collimator and moderating material to achieve boron neutron capture enhanced fast neutron therapy.
abstract: The combination of fast neutron therapy and boron neutron capture therapy is currently being studied as a possible treatment for some radio-resistant brain tumours. In an attempt to design a boron-enhanced fast neutron therapy beam for the Fermilab Fast Neutron Therapy Facility, the use of moderating material surrounding the patient's head has been investigated. Graphite, polyethylene, water and heavy water were studied as moderating materials, using MCNP. The use of tungsten, iron, lead and bismuth as materials for a small filter and collimator near the patient's head was investigated. Calculations showed that a filter and collimator made of tungsten with a graphite moderator was capable of producing a dose enhancement of 17.3 +/- 0.6% for a 100 microg g(-1) loading of 10B for a 5.6 cm diameter beam while delivering 1.5 Gy in 7 min.
authors.affiliation: X-5, Applied Physics Division, Los Alamos National Laboratory, MS F663, Los Alamos, NM 87545, USA. j.sweezy@lanl.gov
authors.forename: J
authors.initials: J
authors.lastname: Sweezy
authors.forename: Nolan
authors.initials: N
authors.lastname: Hertel
authors.forename: Arlene
authors.initials: A
authors.lastname: Lennox
mesh_terms: D016754:Boron Neutron Capture Therapy / Q000379:methods*; D001932:Brain Neoplasms / Q000532:radiotherapy*; D003131:Combined Modality Therapy; D003198:Computer Simulation; D005214:Fast Neutrons / Q000627:therapeutic use*; D005374:Filtration / Q000379:methods*; D006801:Humans; D008422:Materials Testing; D008954:Models, Biological; D011874:Radiometry / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*