Efectos Citogenéticos de Tasas de Dosis de Radiación Convencionales y Ultra Altas en Linfocitos Humanos: Análisis...

Ultra-high dose rate (UHDR) radiation, popularly known as FLASH, has been demonstrated to selectively kill tumor cells with minimal or negligible effects on normal cells but the biological effects induced by UHDR are not fully understood.

In this study, cytogenetic damage induced by UHDR radiation was compared with conventional dose rate (CDR) in human peripheral blood lymphocytes. Human blood samples were irradiated with 3 Gy and 8 Gy doses using 9 MeV electrons at 2 different dose rates: CDR 1 Gy/min and UHDR 600 Gy/Sec. Unstable and stable chromosomal aberrations were detected by fluorescence in situ hybridization (FISH).

Reduced yields of chromosomal aberrations were observed after UHDR radiation at both radiation doses and the extent of reduction was more in colcemid arrested metaphase chromosomes than in G2-PCCs.

The reduced yields of chromosomal aberrations detected after UHDR of electrons may be due to rapid delivery of radiation dose within seconds, resulting in a non-uniform exposure of lymphocytes with varying levels of DNA damage induction. Future studies using well defined human equivalent in vivo and in vitro model systems are required to determine the underlying mechanisms for the FLASH effects.