Effects of Radiation: The Paradigm Shifts, Adaptive Response and Bystander Models



AC Ugwu 1, AO Imo 2, VC Ikamaise 3

1-Department of Medical Radiography, Nnamdi Azikiwe University, Nnewi Campus, Anambra State, Nigeria. 2-Radiology Department, Ebonyi State University Teaching Hospital, Ebonyi State, Nigeria. 3-Department of Medical Radiography, University of Calabar, Crossriver State, Nigeria.

IJMBS 2009;1(2):61-66


Evidence accumulated over the last 50 years shows that radiation also has, indirect ‘non-target’ actions in which effects of radiation on cells or tissues are transported to cells or tissues that were not ‘hit’ by radiation, leading to changes in their function. Radiation- induced cytotoxic and genotoxic effects by the bystander effect is in contrast to the observations of the adaptive responses, which are generally induced following exposure to low dose, low linear energy transfer radiation and which tend to attenuate radiation – induced damage. In this paper the evidence of the radiation induced bystander effect and adaptive response are discussed. The implications of these non-targeted effects to radiotherapy and radiation protection practices are also highlighted.

Keywords: bystander effects, adaptive response, radiation protection.

Link/DOI: http://journals.sfu.ca/ijmbs/index.php/ijmbs/article/view/22/62