Mixed Field Dosimetry of Neutron Beams for Boron Neutron Capture Therapy at the Massachusetts Institute of Technology
An epithermal neutron beam has been developed1,2 for Boron Neutron Capture Therapy (BNCT) at the Massachusetts Institute of Technology Research Reactor (MITR-II). The neutron beam has been used to treat two patients as part of a Phase I clinical trial for subcutaneous melanoma of the extremities. The clinical dosimetry of epithermal neutron beams for BNCT is considerably different from that of fast neutron beams used for fast neutron therapy. In BNCT, the incident radiation field consists primarily of neutrons in the 0.5 eV to ≈20 keV range; higher energy neutrons, with energies up to 15 MeV, and photons of 0–10 MeV, are present as contaminants. Therefore, separate macroscopic doses, including those from thermal and fast neutrons, photons, and the B-10(n,α)Li-7 reaction, need to be determined.
KeywordsThermal Neutron Fast Neutron Ionization Chamber Neutron Energy Neutron Beam
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