Effects of low dose and low dose rate low linear energy transfer radiation on animals – review of recent studies relevant for carcinogenesis

Abstract

Purpose: Carcinogenic effects of radiation are often assumed to be universally understood, more often than, for example, carcinogenic effects of many different chemicals. This in turn leads to an assumption that any dose of radiation, delivered at any dose rate, poses a serious health challenge. This remains an issue of dispute and low dose radiation research is focused on understanding whether these exposures contribute to cancer incidence. This review is focused on the low linear energy transfer (low LET) radiation exposures for which the data is the most abundant in recent years. Materials and methods: Review of the literature between 2008 and today, highlighting some of the most diverse studies in low dose research. Results: Low dose and low dose rate, low LET ionizing radiation animal studies suggest that the effects of exposure very much depend on animal genotype and health status. Conclusions: Only the integration of all of the data from different models and studies will lead to a fuller understanding of low dose radiation effects. Therefore, we hope to see an increase in international archival efforts and exchange of raw data information opening the possibilities for new types of meta analyses.

A multi-omics longitudinal study of the murine retinal response to chronic low-dose irradiation and simulated microgravity

“…Second, the animals were radiated by low-dose gamma rays which do not represent space radiation. Ground-based low-dose gamma or x-ray radiation studies are often used to study the effect of space-relevant radiation exposures (in terms of total dose) on different tissues/systems 6 , 47 , 48 as to inform future space radiation experiments and form an initial understanding of the impacts across radiation doses and types. However, further studies should be implemented with higher dose gamma radiation and GCR simulations to leverage a more realistic space radiation analog.…”

Comparison and calibration of dose delivered by 137Cs and x-ray irradiators in mice

“…The highest dose rate is observed for the Mark I-68, while being ∼40% lower for the X-Rad320 at 320 kVp. It has been shown that dose rates play an important role in the biological effects of radiation (Hall and Brenner 1991, Rühm et al 2016, Brooks et al 2016, and, in particular, for small animal irradiation (Down et al 1991, Paunesku et al 2021. Furthermore, high energy photons deliver more dose per photon and unit of length, being higher for 137 Cs than for x-rays (figure 9).…”

Cancer and Non-Cancer Effects Following Ionizing Irradiation

“…Ionizing radiation is used to treat cancer [ 1 , 2 ], but is also a carcinogen [ 3 , 4 ]. Alongside that, there has been mounting interest not only in radiotherapy for non-cancer diseases [ 5 , 6 , 7 , 8 , 9 ], but also the non-cancer effects of radiation exposure that occur at doses or dose rates much lower than previously suggested or considered [ 9 , 10 , 11 ].…”