Blood samples were collected from seven healthy donors (four male and three female volunteers, age 21–25 years) by venipuncture into 5 mL heparinized tubes after informed written consent. Donors were nonsmokers with good health (no obvious illness at time of donation) and no history of exposure to chemotherapy or radiotherapy within the last two years.
Blood samples were aliquoted into 1.5 mL cryovials which were either irradiated with different amounts of X-rays (1, 2, 4 or 6 Gy) or not irradiated and kept as controls (0 Gy). A 3-dimensional radiotherapy plan consisted of 6 MV X-ray, dose rate of 600 MU/min, field size 10 cm2, source to surface distance of 95 cm; prescribed doses of 1, 2, 4 or 6 Gy at 5 cm depth were computed on a simulated water phantom using Acuros XB dose calculation algorithm in the Eclipse Treatment Planning System version 16.1 (Varian Medical Systems, Milpitas, CA). Tubes of sampled blood were set up under the treatment plan conditions, placed into the holder at a depth of 5 cm in the water phantom, and irradiated using a TrueBeam linear accelerator (Varian Medical Systems, Palo Alto, CA). In this study, the radiation dose at a depth of interest was determined using a Farmer chamber FC65-G (IBA Dosimetry, Germany), the standard clinical reference dosimeter for high-energy photons.
Blood samples were aliquoted into 1.5 mL cryovials which were either irradiated with different amounts of X-rays (1, 2, 4 or 6 Gy) or not irradiated and kept as controls (0 Gy). A 3-dimensional radiotherapy plan consisted of 6 MV X-ray, dose rate of 600 MU/min, field size 10 cm2, source to surface distance of 95 cm; prescribed doses of 1, 2, 4 or 6 Gy at 5 cm depth were computed on a simulated water phantom using Acuros XB dose calculation algorithm in the Eclipse Treatment Planning System version 16.1 (Varian Medical Systems, Milpitas, CA). Tubes of sampled blood were set up under the treatment plan conditions, placed into the holder at a depth of 5 cm in the water phantom, and irradiated using a TrueBeam linear accelerator (Varian Medical Systems, Palo Alto, CA). In this study, the radiation dose at a depth of interest was determined using a Farmer chamber FC65-G (IBA Dosimetry, Germany), the standard clinical reference dosimeter for high-energy photons.