Improved survival of non-Hodgkin’s Lymphoma patients was observed when they were subjected to 10 or 15 cGy total-body or half-body irradiation (TBI or HBI) interspersed between radiation treatments to the tumor (Total dose=1.5 Gy) (Sakamoto, 2004).

These data indicate that low radiation doses reduce the cancer risk consistent with radiation hormesis and contradicting the LNT model.

Tumors outside the HBI field also regressed in response to the repeated LDR exposures (Pollycove 2007), indicating that the the cancer therapeutic effect was due to a systemic response (e.g. immune enhancement), and not due to tumor cell-killing from the total dose of 1.5 Gy.

References

SAKAMOTO, K. Radiobiological basis for cancer therapy by total or half-body irradiation. Nonlinearity Biol Toxicol Med, v. 2, n. 4, p. 293-316, Oct 2004. https://www.ncbi.nlm.nih.gov/pubmed/19330149

Second cancers per kg of tissue is lower in parts of body exposed to low-dose radiation in radiation therapy patients when compared to the parts of the body that had no radiation exposre

This study (Tubiana et al., 2011) was carried out on a French-United Kingdom cohort of 5,000 survivors of a childhood cancer cohort treated in eight centers in France and the UK before 1985 and followed on average for 29 years. Second cancers per kg of tissue were determined and plotted as a function of the average radiation dose to the tissue during radiation therapy.

Reduction of second cancers per kg of tissue was observed in regions of body subjected to radiation dose of ~20 cGy during radiation therapy, in comparison to regions not subjected to any radiation dose.

These data indicate that low radiation doses reduce the cancer risk consistent with radiation hormesis and contradicting the LNT…

Immune system plays a very important role in preventing cancer, as indicated by the increase in the cancer risk when the immune system is suppressed in organ-transplant recipients and AIDS patients (Oliveira Cobucci, 2012).

Immune system response declines rapidly with age (Levin, 2014), qualitatively explaining the well-known age-related increase in cancers risk.

Low-dose radiation boosts the immune system response (see graph below) (Yang, 2014)

and so would reduce cancer risk.

Many publications have claimed that increased residential radon levels increase lung cancer risk. However, there is a major problem with such publications.

Whereas high-dose radiation, received in a short time, has been observed to increase cancer risk as observed in the atomic bomb survivors, low radiation doses have been observed to reduce the cancer risk in many studies (Berrington et al, 2001; Doss, 2018; Linet et al, 2017; Pollycove & Feinendegen, 2008; Sponsler & Cameron, 2005). In view of such data, it would not be appropriate to use the linear no-threshold (LNT) model for analyzing the radon-lung cancer data in order to determine the dose-response shape or to estimate the lung cancer risk due to low levels of residential radon. Therefore, a vast majority of the publications on radon and lung cancer risk, which utilize the LNT model for analyzing the data, including meta-analyses of such publications, do not have…