Dose distribution of neutron beam and chromosome analysis
Chromosome analysis using peripheral lymphocytes is a sensitive and reliable indicator of the biological effect of radiation at low radiation doses. In the present study, using this chromosome aberration analysis, we tried to investigate the radiation dose distribution within and around the radiation field of a 6 MeV neutron beam. The efficient induction of dicentrics and rings at the irradiation of neutrons compared to those of gamma or X rays especially in a lower dose range, results in a dominant linear component in the linear quadratic model in the dose response relation of a chromosome aberration formation. A marked increase of RBE (relative biological effectiveness) in a lower dose range of neutrons was demonstrated. The radiation doses of the neutron beam as a function of depth, estimated from the yields of dicentrics and rings in a water phantom revealed a fairly good agreement with doses that were physically obtained. The radiation portal margin of the neutron beam was demonstrated to be not as sharp due to a wide penumbra. This wide penumbra and high RBE value, especially at lower dose range of the neutron beam may contribute to the induction of secondary malignancies in the normal tissue surrounding the tumor mass.
- Research Organization:
- Tokyo Medical and Dental Univ. (Japan)
- OSTI ID:
- 5200126
- Journal Information:
- Int. J. Radiat. Oncol., Biol. Phys.; (United States), Vol. 14:3
- Country of Publication:
- United States
- Language:
- English
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61 RADIATION PROTECTION AND DOSIMETRY
CHROMOSOMAL ABERRATIONS
RADIOINDUCTION
LYMPHOCYTES
RADIOSENSITIVITY
NEUTRON BEAMS
RADIATION DOSE DISTRIBUTIONS
DOSE-RESPONSE RELATIONSHIPS
FAST NEUTRONS
GENETIC RADIATION EFFECTS
IN VITRO
LOW DOSE IRRADIATION
PHANTOMS
RBE
WATER
ANIMAL CELLS
BARYONS
BEAMS
BIOLOGICAL EFFECTS
BIOLOGICAL MATERIALS
BIOLOGICAL RADIATION EFFECTS
BLOOD
BLOOD CELLS
BODY FLUIDS
CONNECTIVE TISSUE CELLS
ELEMENTARY PARTICLES
FERMIONS
GENETIC EFFECTS
HADRONS
HYDROGEN COMPOUNDS
IRRADIATION
LEUKOCYTES
MATERIALS
MOCKUP
MUTATIONS
NEUTRONS
NUCLEON BEAMS
NUCLEONS
OXYGEN COMPOUNDS
PARTICLE BEAMS
RADIATION EFFECTS
SOMATIC CELLS
STRUCTURAL MODELS
560120* - Radiation Effects on Biochemicals
Cells
& Tissue Culture
655003 - Medical Physics- Dosimetry