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E. A. Domina
R. E. Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology of the National Academy of Sciences of Ukraine, 45 Vasylkivska St., Kyiv, 03022, Ukraine
RADIATION;INDUCED DESTABILIZATION OF THE BLOOD LYMPHOCYTES’ GENOME IN CANCER PATIENTS DEPENDING ON THEIR INDIVIDUAL RADIOSENSITIVITY
Objective: determination of the patterns of chromosome aberration formation in peripheral blood lymphocytes of
cancer patients with different types and tumors’ localization, taking into account the individual radiosensitivity of
the organism.
Methods. Test system of peripheral blood lymphocyte culture from patients with tumors of various types and locations and conditionally healthy individuals. Metaphase analysis of chromosome aberrations was performed in the
first mitosis. Individual radiosensitivity was determined based on test irradiation of lymphocytes in the G2 period
of the mitotic cycle. Quantitative assessment of the chromosomal damage formation and construction of standard
calibration dose curves based on cytogenetic indicators in irradiated blood lymphocytes were performed using the
spline regression model.
Results. In primary cancer patients with different tumor localization, the spontaneous level of chromosome aberrations in peripheral blood T-lymphocytes is already compromised before the start of radiation therapy, and therefore
the cells can only be defined as conditionally healthy (non-malignant). At the same time, the average frequency of
chromosome aberrations (0.07 per cell), chromatid-type aberrations (0.05 per cell) and dicentrics (0.016 per cell)
in peripheral blood lymphocytes of cancer patients significantly exceeds the average population level and similar
indicators in the control group (conditionally healthy donors). It has been proven for the first time that the nature
of the dose dependence of the aberration yield during irradiation in the range of low doses (0.1–0.5 Gy) is influenced by the individual radiosensitivity of cancer patients, determined by the chromosomal G2 test, with an increase
in which the boundaries of the plateau (dose-independent area) on the dose-effect curve change.
Conclusion. Determination of individual radiosensitivity of cancer patients before the start of radiation therapy
allows to reasonably identify individuals with a high risk of secondary tumors of radiation genesis, which is important for personalized planning of therapeutic radiation schemes.
Key words: ionizing radiation; radiation therapy; cancer patients; individual radiosensitivity; chromosomal aberrations.
Problems of Radiation Medicine and Radiobiology.
2025;30:236-247. doi: 10.33145/2304-8336-2025-30-236-247
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