Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

2 Publications
In vivo dose response studies for laser driven particle beams
Oppelt, M.; Baumann, M.; Bergmann, R.; Beyreuther, E.; Brüchner, K.; Kaluza, M.; Karsch, L.; Krause, M.; Laschinsky, L.; Leßmann, E.; Nicolai, M.; Reuter, M.; Sävert, A.; Schnell, M.; Schürer, M.; Pawelke, J.;
Purpose: The development of proton and ion acceleration by ultra high intensity lasers for cancer therapy promises the realization of compact and economic particle accelerators that can be integrated in already existing clinics. For translational research towards clinical application the radiobiological consequences of laser accelerated and therewith ultra-short pulsed particle beams with high pulse dose have to be investigated. After extensive in vitro dose response studies with laser driven electron and proton beams, in vivo experiments have been performed within the joint research project “onCOOPtics” as next translational step.

Material/Methods: A mouse tumor model suitable for currently available low energy laser protons was developed, tested and successfully used. The already in vitro established laser based irradiation technology was further developed for the animal model in terms of beam transport, beam monitoring, dose delivery and dosimetry allowing to apply a prescribed dose to each tumor and to determine the absolute dose received. For precise and reproducible positioning at the irradiation site a system for mouse fixation, tumor positioning and position verification was implemented as described in [Schürer et al 2012]. Experiments were carried out at the 30 Terawatt Jena Titanium:Sapphire (JeTi) laser system. Laser pulses of 28 fs duration were focused into a hydrogen gas jet accelerating electrons to energies of up to a few 10 MeV. In vivo tumor irradiation was realized for murine sarcoma KHT and human squamous cell carcinoma FaDu. Doses up to 14 Gy were applied at mean dose rates of 1-2 Gy/min and irradiation induced tumor growth delay was investigated. Comparison irradiations were performed at a conventional therapy LINAC with the same setup for irradiation and absolute dose determination.
Results: The reliability and stability of all implemented setup components and methods were proven by numerous irradiations over a period of several months. Dose response curves of tumor growth delay were generated for direct comparison of ultra short pulsed laser accelerated and conventional continuous electron beam. The ongoing data evaluation by now shows no significant difference in RBE for laser driven electrons.
Conclusion: The successful establishment of all technical requirements for and the world wide first performance of systematic animal studies with laser accelerated electrons mark an important step towards the clinical application of laser accelerated particle beams. The realization of in vivo studies with laser driven proton beams is now feasible.
The authors thank for the contribution of the Jeti accelerator crew at Friedrich-Schiller-University Jena, Ralf Bergmann (HZDR) and for the support by the German Ministry of Education and Research (BMBF) Grant Nr 03Z1N511.
  • Lecture (Conference)
    2nd ESTRO Forum, 19.-23.04.2013, Geneva, Switzerland
  • Abstract in refereed journal
    Radiotherapy and Oncology 106(2013)Suppl 2, 566

Publ.-Id: 18445 - Permalink