Targets, pools, shoulders, and communication – a reflection on the evolution of low-dose radiobiology

Abstract

This reflection aims to look at the evolution of thinking about radiation dose response relationships from the early years of the journal when target theory prevailed to the present day when dose response is seen as a more holistic process involving multiple levels of organization and communication. The review is structured to consider how the old ideas evolved leading to apparently abrupt paradigm shifts. The odd data leading to these conceptual shifts are reviewed. Topics, which are currently still not mainstream are considered with a view to how they may change the future of radiobiology. Finally some personal reflections on the insights gained during the writing of the review are presented. The major conclusion from this study is that ideas concerning survival curves and radiation dose responses evolved and (epi)mutated gradually, driven in a large part by the techniques available for studying radiobiological processes. The illusion of abrupt paradigm shifts is not really borne out by the history when primary references are studied rather than textbooks or reviews. The textbooks necessarily simplify and distil complex data to provide a ‘take-home message’ while reviews are usually very personal collations selected among the vast amount of scientific literature. Primary references reveal the context of the discussion and the caveats and uncertainties of the authors.

Keywords:

• Target
• non-targeted effects
• low-dose radiation
• shouldered survival curves
• recovery

Acknowledgment

The authors are very grateful to Andrej Rusin for formatting the paper and for constructing the figures.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Carmel Mothersill

Dr. Carmel Mothersill is a professor at McMaster University, Canada. Her research interests involve the understanding of the risks of very low doses of ionizing radiation to humans and the environment, with particular emphasis on the mechanisms of low-dose effects. Identification of early events and the mechanisms involved in radiation carcinogenesis are also examined. Study of the mechanisms involved in genomic instability, and their relevance to the repair of radiation damage and radiation-induced carcinogenesis. Development of bio-indicators of radiation stress in non-human species after low doses of alpha, beta, and gamma radioisotopes involve in uranium, radium, and tritium decay.

Colin Seymour

Dr. Colin Seymour is a professor at McMaster University, Canada. His research interests include the understanding of very low doses of ionizing radiation to humans and the environment. His research topics include genomic instability, the radiation-induced bystander effect, and the development of biomarkers of radiation stress in both humans and non-human species.