Localized Synchrotron Irradiation of Mouse Skin Induces Persistent Systemic Genotoxic and Immune Responses

Area of Science:

• Radiation biology
• Medical physics
• Immunology

Background:

• Nontargeted (systemic) effects of ionizing radiation are gaining attention.
• Understanding these effects is crucial for radiation safety and therapeutic applications.

Purpose of the Study:

• To investigate radiation-induced nontargeted effects using synchrotron radiation in mice.
• To assess the impact of different beam configurations and doses on systemic responses.

Main Methods:

• Local irradiation of C57BL/6 mice using synchrotron X-ray broad and microbeam radiotherapy.
• Monitoring of DNA damage (OCDL, DSB), apoptosis, and immune responses (cytokines, cell frequencies) in irradiated and unirradiated tissues.
• Analysis of effects at 1 and 4 days post-irradiation.

Main Results:

• All tested radiation settings induced persistent systemic effects, even with short exposures and small irradiated areas.
• Elevated oxidatively induced clustered DNA lesions (OCDL) were observed in various unirradiated tissues.
• Changes in plasma cytokine levels and immune cell frequencies (macrophages, neutrophils, T lymphocytes) were detected systemically.

Conclusions:

• Radiation therapy can induce significant nontargeted, systemic effects impacting normal tissues and immune responses.
• Findings necessitate careful consideration of beam configuration and dose in radiation treatment planning to minimize adverse systemic effects.
• Further research is needed to fully elucidate the mechanisms and clinical implications of these systemic radiation effects.