Data for: Electron dose rate and oxygen depletion protect zebrafish embryos from radiation damage

Primary data and data description to publication: Electron dose rate and oxygen depletion protect zebrafish embryos from radiation damage Abstract: Background and purpose In consequence of a previous study, where no protecting proton Flash effect was found for zebrafish embryos, potential reasons and requirements for inducing a Flash effect should be investigated with the beam pulse structure and the partial oxygen pressure (pO2) as relevant parameters. Materials and methods The experiments were performed at the research electron accelerator ELBE, whose variable pulse structure enables dose delivery as electron Flash and quasi-continuously (reference). Zebrafish embryos were irradiated with ~26 Gy either continuously with a dose rate of ~6.7 Gy/min or in one 111 µs long pulse with a pulse dose rate of 109 Gy/s and a mean dose rate of 105 Gy/s, respectively. Using the OxyLite system to measure the pO2 a low- (pO2 ≤ 5 mmHg) and a high-pO2 group were defined on basis of the oxygen depletion kinetics in sealed embryo samples. Results A protective Flash effect was seen for most endpoints ranging from 4 % less reduction in embryo length to about 20 – 25 % less embryos with spinal curvature and pericardial edema, relative to reference irradiation. The reduction of pO2 below atmospheric levels (148 mmHg) resulted in higher protection, which was however more pronounced in the low-pO2 group. Conclusion The Flash experiment at ELBE showed that the zebrafish embryo model is appropriate for studying the radiobiological response of high dose rate irradiation. Pulse dose and pulse dose rate as important beam parameters were confirmed as well as the pivotal role of pO2 during irradiation.