title: DNA-repair, cell killing and normal tissue damage.
abstract: BACKGROUND
  Side effects of radiotherapy in normal tissue is determined by a variety of factors of which cellular and genetic contributions are described here.
  
  
  METHODS
  Review.
  
  
  RESULTS
  Normal tissue damage after irradiation is largely due to loss of cellular proliferative capacity. This can be due to mitotic cell death, apoptosis, or terminal differentiation. Dead or differentiated cells release cytokines which additionally modulate the tissue response. DNA damage, in particular non-reparable or misrepaired double-strand breaks are considered the basic lesion leading to G1-arrest and ultimately to cell inactivation.
  
  
  CONCLUSIONS
  Evidence for genetic bases of normal tissue response, cell killing and DNA-repair capacity is presented. However, a direct link of all 3 endpoints has not yet been proved directly.
authors.affiliation: Abteilung für Strahlentherapie, Universitätskrankenhaus Hamburg-Eppendorf. dahm@uke.uni-hamburg.de
authors.forename: J
authors.initials: J
authors.lastname: Dahm-Daphi
authors.forename: E
authors.initials: E
authors.lastname: Dikomey
authors.forename: I
authors.initials: I
authors.lastname: Brammer
mesh_terms: D000818:Animals; D002453:Cell Cycle / Q000528:radiation effects; D002470:Cell Survival / Q000528:radiation effects*; D016207:Cytokines / Q000502:physiology; D004247:DNA / Q000528:radiation effects; D004249:DNA Damage; D004260:DNA Repair / Q000528:radiation effects*; D006801:Humans; D008954:Models, Biological; D011878:Radiotherapy / Q000009:adverse effects*
chemical_list: D016207:Cytokines; D004247:DNA