Research Article Summary
• Primary focus:
This review examines the biological effects of low-dose ionizing radiation (LDR) and evaluates whether LDR may play a role in cancer treatment and normal-tissue protection, distinct from the damaging effects observed at high radiation doses.
• Low-dose vs. high-dose responses:
The authors emphasize that low-dose radiation elicits fundamentally different biological responses compared to high-dose radiation. At doses below approximately 0.1–0.2 Gy, cellular systems often activate regulatory and protective mechanisms rather than accumulating irreversible damage.
• Key biological mechanisms:
LDR is shown to stimulate processes such as enhanced DNA repair capacity, antioxidant activity, immune activation, adaptive response, bystander effects, hyper-radiosensitivity, and induced radioresistance. These mechanisms contribute to maintaining tissue homeostasis and reducing long-term biological stress.
• Cancer-related implications:
The article reviews evidence that LDR can inhibit tumor metastasis, enhance immune surveillance, and selectively protect normal tissue without conferring the same protective benefits to tumor cells. This raises the possibility of using LDR strategically to improve therapeutic outcomes when combined with conventional cancer treatments.
• Risk model implications:
The authors argue that the Linear No-Threshold (LNT) hypothesis does not adequately describe low-dose biological reality, as it ignores adaptive and compensatory mechanisms. They suggest that risk assessment frameworks should incorporate modern radiobiological evidence rather than relying solely on linear extrapolation from high-dose data.