Problems in determining the absorbed dose in thermal neutron and gamma ray mixed fields: a tissue-equivalent phantom dosimeter for boron neutron capture therapy (BNCT)

摘要

Abstract: In boron neutron capture therapy (BNCT) the absorbed dose consists of the contribution of many radiation components, and its spatial distribution is highly nonuniform. Three- dimensional dose determinations are therefore to be done, and the utilized dosimeters have to perturb the radiation field as little as possible. Thermoluminescent dosimeters (TLDs) are widely utilized for mapping the radiation field. But TLDs with high sensitivity for thermal neutrons have shown an irreversible damage from such neutrons producing an alteration in the response. A tissue equivalent phantom dosimeter is proposed allowing a 3-D determination of absorbed dose by an NMR imaging of the phantom. !5