Phạm Ngọc Duy, Chế Quang Tuấn, Trần Thanh Mai, Lê Thị Thùy Linh, Hán Huỳnh Diện, Lê Thị Bích Thy, Phạm Xuân Hải

Abstract

Radiotherapy not only kills the cancer cells but also non-selectively affects the surrounding normal cells. The method for analysing chromosome aberrations induced by DNA damage in G2 phase of the cell cycle is expected to be used to assess the radiosensitivity for improving treatment efficacy and radiation safety. In this study, the human peripheral blood lymphocytes samples were cultured in vitro and irradiated by X-ray sources with the doses of 0.5; 1.0; 2.0; 4.0 Gy after 69 hours’ cultivation, when most of the lymphocyte cells were in G2 phase. The samples were continued to be treated with 4 mM caffeine, cells harvesting and scoring of microscope slides for determining the chromatid break frequency in the samples with and without caffeine treatment. The radiosensitivity was evaluated by IRS = (G2/G2caffeine) × 100%. The results exhibited that this method has greatly potential application in assessing individual radiosensitivity, especially for cancer patients before radiation therapy.