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 model.

References

TUBIANA, M. et al. A new method of assessing the dose-carcinogenic effect relationship in patients exposed to ionizing radiation. A concise presentation of preliminary data. Health Phys, v. 100, n. 3, p. 296-9, Mar 2011. https://www.ncbi.nlm.nih.gov/pubmed/21595074