RBE: Mechanisms inferred from cytogenetics

E. H. Goodwin, Michael Cornforth

Research output: Contribution to journalArticle

6 Scopus citations

Abstract

Cyclotron-accelerated heavy ion beams provide a fine degree of control over the physical parameters of radiation. Cytogenetics affords a view into the irradiated cell at the resolution of chromosomes. Combined they form a powerful means to probe the mechanisms of RBE. Cytogenetic studies with high energy heavy ion beams reveal three LET-dependent trends for 1) level of initial damage, 2) distribution of damage among cells, and 3) lesion severity. The number of initial breaks per unit dose increases from a low-LET plateau to a peak at ∼180 keV/μm and declines thereafter. Overdispersion of breaks is significant above ∼100 keV/μm. Lesion severity, indicated by the level of chromosomal fragments that have not restituted even after long repair times, increases with LET. Similar studies with very low energy 238Pu alpha particles (120 keV/μm) reveal higher levels of initial breakage per unit dose, fewer residual fragments and a higher level of misrepair when compared to high energy heavy ions at the same LET. These observations would suggest that track structure is an important factor in genetic damage in addition to LET.

Original languageEnglish (US)
Pages (from-to)249-255
Number of pages7
JournalAdvances in Space Research
Volume14
Issue number10
DOIs
StatePublished - 1994

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ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

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