The RBE of the leakage radiation from the Hiletron neutron therapy unit.
AffiliationPaterson Laboratories, Christie Hospital and Holt Radium Institute, Manchester.
MetadataShow full item record
AbstractThe RBE of the leakage radiation from the Hiletron 14.7 MeV neutron therapy unit has been measured using three sensitive biological systems in mice, which differ markedly in their radiobiological characteristics. These systems comprise type A spermatogonia and bone marrow stem cells, which are affected insignificantly by dose rate, and pigment abnormalities in hair follicles which are affected markedly by dose rate. For mice irradiated at 10 cm depth in a water phantom, the leakage radiation up to 40 cm from the beam axis was virtually as effective as the primary beam for the latter two biological systems, and for spermatogonia in mice when irradiated in air. At this distance, the total dose rate was about 0.2 cGy (rad) per minute (3% of that in the primary beam), and the gamma-ray component was about 70%. This equal effectiveness of the total dose for all three systems was considered fortuitous, and it implied high RBE values for equal effect with the small neutron component at far distances. Considering published data on RBE versus neutron energy, the evidence suggested either a positive interaction of neutron and gamma-ray components in killing bone marrow stem cells when the neutron component was less than 40% of the total dose, or an increased efficiency of neutrons when delivered at very low dose rates. However the components were additive in killing spermatogonia.
CitationThe RBE of the leakage radiation from the Hiletron neutron therapy unit. 1983, 56 (668):551-8 Br J Radiol
JournalBritish Journal of Radiology
- Interaction between the biological effects of high- and low-LET radiation dose components in a mixed field exposure.
- Authors: Mason AJ, Giusti V, Green S, Munck af Rosenschöld P, Beynon TD, Hopewell JW
- Issue date: 2011 Dec
- Changes in RBE of 14-MeV (d + T) neutrons for V79 cells irradiated in air and in a phantom: is RBE enhanced near the surface?
- Authors: Schalla S, Herskind C, Höver KH, Lorenz WJ, Hahn EW
- Issue date: 1998 Apr
- RBE values and repair characteristics for colo-rectal injury after caesium 137 gamma-ray and neutron irradiation. II. Fractionation up to ten doses.
- Authors: Terry NH, Denekamp J
- Issue date: 1984 Jul
- RBE values of d (16) + Be and d (50) + Be neutrons for chromosome rearrangements induced in mouse spermatogonia.
- Authors: Pécrot M, Léonard A, Wambersie A, Meulders JP
- Issue date: 1977 Jun