Is interindividual variation of cellular radiosensitivity real or artifactual?

Area of Science:

• Radiobiology
• Immunology
• Cellular Biology

Background:

• Cellular radiosensitivity is a critical factor in radiation oncology and radiation protection.
• Understanding interindividual variation in radiosensitivity is essential for personalized medicine and risk assessment.
• Human G0 T lymphocytes are a relevant model for studying radiosensitivity due to their quiescent state.

Purpose of the Study:

• To investigate the extent of interindividual variation in the radiosensitivity of human G0 T lymphocytes.
• To compare the variability of radiosensitivity between different individuals and within a single individual.
• To determine if significant differences exist in radiation dose-survival curves among healthy donors.

Main Methods:

• A dose-survival assay was developed using peripheral blood human G0 T lymphocytes.
• Cellular radiosensitivity was assessed by measuring the surviving fraction after exposure to various X-ray doses.
• Variability was compared between 31 different individuals and 28 repeated tests on a single donor.

Main Results:

• The X-ray dose required to kill 90% of cells (D10) was 3.59 ± 0.18 Gy for different individuals and 3.66 ± 0.21 Gy for repeated tests.
• Analysis of variance showed no significant difference in D10 value variation between the two groups.
• Similar results were observed for D50 and D90, indicating low interindividual variability in radiosensitivity.

Conclusions:

• Interindividual variation in the radiosensitivity of human G0 T lymphocytes is minimal.
• The colony-forming ability of irradiated G0 lymphocytes demonstrates consistent radiosensitivity across different individuals.
• These findings suggest that cellular radiosensitivity, as measured by this assay, is largely consistent among healthy individuals.