Radiobiological characterization of laser driven particle beams – Dresden activities

The long-term aim of developing laser based particle acceleration towards clinical application requires not only substantial technological progress, but also new technical solutions for dose delivery and quality assurance as well as comprehensive research on the radiobiological consequences of ultra-short radiation pulses with high pulse dose.
During the last years the laser driven technology was developed at such a rate that cell samples and small animals can be irradiated. Within the joint research project “onCOOPtics” extensive in vitro studies with several human tumor and normal tissue cells were performed revealing comparable radiobiological effects of laser driven and conventional electron and proton beams1,2. Using the same cell lines, these results were substantiated comparing the radiobiological response to ultra-short pulsed electron bunches (pulse dose rates of ≤1012 Gy/min) and continuous electron delivery at the radiation source ELBE3.
In a second translational step, in vivo experiments were established. Although the experiments were motivated by future proton trials, first attempts were performed with electrons at the laser system JETI4, since the delivery of prescribed homogeneous doses to a 3D target volume is easier for electrons than for protons. A full scale animal experiment was realized for the HNSCC FaDu grown on nude mice ear. The radiation induced tumor growth delay was determined and compared to those obtained after similar treatment at a conventional clinical LINAC. Again, no significant difference in the radiation response to both radiation qualities was revealed, whereas the successful performance of such a comprehensive experiment campaign underlines the stability and reproducibility of all implemented methods and setup components.
During this experiment campaign several limitations of the model were identified which were in the following redressed by co-injection of LN229 glioblastoma tumour cells with Matrigel5. Results of this optimization process and the status of the experiments with laser driven protons at the laser system DRACO will be presented.
The work was supported by the German Government, Federal Ministry of Education and Research, grant nos. 03ZIK445 and 03Z1N511.
1Laschinsky L et al. (2012) J. Radiat. Res. 53(3): 395-403.
2Zeil K et al. (2012) Appl. Phys. B 110(4): 437-444.
3Beyreuther E et al. (2015) Int. J. Radiat. Biol. 91(8): 643-652.
4Oppelt M et al. (2015) Radiat. Environ. Biophys. 54(2): 155-166.
5Beyreuther E et al. (2017) PloS One 12.5 (2017): e0177428.