ABSTRACT
The relative biologic effectiveness (RBE) of fast neutrons in the production of single strand DNA breaks is 1.6 as compared to that of 250 kVp x rays. Monolayers of L-929 cells were treated with dinitrophenol during irradiation to prevent the DNA strands from rejoining; the extent of DNA damage was measured by the alkaline sucrose sedimentation method. The RBE for DNA damage is essentially the same as the RBE measured by cell survival methods.
Subject(s)
DNA, Single-Stranded/radiation effects , Radiation Effects , Animals , Cells, Cultured , Dose-Response Relationship, Radiation , Fast Neutrons/adverse effects , Hydrogen-Ion Concentration , Mice , Sucrose , Thermoluminescent Dosimetry , X-Rays/adverse effectsABSTRACT
Because of recent interest in the use of neutrons for radiotherapy, there has been an increased interest in the radiology of neutrons. In this irradiated cell study, a 1.3 MeV accelerator produced beam currents over 100 muA on the water-cooled 3-mm thick beryllium disk target. The monolayer of irradiated cells was neutron-shielded by about 700 kg of paraffin. The neutron energy spectrum for the 9Be(d,n)10B reaction was obtained, with an average neutron energy calculated to be between 3.3 and 3.5 MeV, and an average linear energy transfer calculated at more than 30 keV/micron.
Subject(s)
Cells, Cultured/radiation effects , Fast Neutrons , Neutrons , Radiation Effects , Energy Transfer , Humans , Indium , Thermoluminescent DosimetryABSTRACT
Mouse L-929 cells were exposed in a monolayer to x rays and to a 3.5 MeV neutron beam for comparison of damage effects. Single dose experiments showed a radiobiological effectiveness of 1.5 for neutrons when compared to x rays. Both single and paired dose experiments indicated that the cells were unable to repair neutron-induced damage. Dinitrophenol was found to increase the survival of those cells irradiated with neutrons.
