Dörr W
Annals of the ICRP. Date of publication 2015 Jun 1;volume 44(1 Suppl):58-68.
1. Ann ICRP. 2015 Jun;44(1 Suppl):58-68. doi: 10.1177/0146645314560686. Epub 2015
Mar 5.
Radiobiology of tissue reactions.
Dörr W(1).
Author information:
(1)Department of Radiation Oncology and Christian Doppler Laboratory for Medical
Radiation Research for Radiooncology, Comprehensive Cancer Centre, Medical
University Vienna/Vienna General Hospital, Waehringer Guertel 18-20, A-1090
Vienna, Austria wolfgang.doerr@meduniwien.ac.at.
Tissue effects of radiation exposure are observed in virtually all normal
tissues, with interactions when several organs are involved. Early reactions
occur in turnover tissues, where proliferative impairment results in hypoplasia;
late reactions, based on combined parenchymal, vascular, and connective tissue
changes, result in loss of function within the exposed volume; consequential late
effects develop through interactions between early and late effects in the same
organ; and very late effects are dominated by vascular sequelae. Invariably,
involvement of the immune system is observed. Importantly, latent times of late
effects are inversely dependent on the biologically equieffective dose. Each
tissue component and--importantly--each individual symptom/endpoint displays a
specific dose-effect relationship. Equieffective doses are modulated by exposure
conditions: in particular, dose-rate reduction--down to chronic levels--and dose
fractionation impact on late responding tissues, while overall exposure time
predominantly affects early (and consequential late) reactions. Consequences of
partial organ exposure are related to tissue architecture. In 'tubular' organs
(gastrointestinal tract, but also vasculature), punctual exposure affects
function in downstream compartments. In 'parallel' organs, such as liver or
lungs, only exposure of a significant (organ-dependent) fraction of the total
volume results in clinical consequences. Forthcoming studies must address
biomarkers of the individual risk for tissue reactions, and strategies to
prevent/mitigate tissue effects after exposure.
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DOI: 10.1177/0146645314560686
PMID: 25816259 [Indexed for MEDLINE]
