gms | German Medical Science

Background: The present technology for proton and ion therapy requires large devices for accelerating and delivering the beams with accordingly high investment costs. Therefore, the potential of several technologies for developing compact and cost effective sources of therapeutic proton or ion beams is intensively studied. One feasible solution may be the interaction of ultra-short, high-intensity laser pulses with matter.

Material and methods: Combining their competences in laser physics and technology as well as in radiation physics and biology the centers ultra optics in Jena and OncoRay in Dresden, respectively, initiated in 2007 the research project onCOOPtics being focused on the long-term goal of developing laser driven particle irradiation devices. The work in Jena is concentrated onto the physics of laser-matter-interaction, the technology of high-power lasers and the development of optimal radiator targets. The research in Dresden comprises the real-time physical characterization of laser driven particle pulses, the investigation of the biological efficiency of this new radiation modality and the development of dedicated therapeutic irradiation equipment. For experiments three high-intensity laser systems are available: JeTi (pulse power: 15 TW, pulse duration: 80 fs) and POLARIS (150 TW, 170 fs) in Jena as well as DRACO (150 TW, 25 fs) in Dresden all equipped with real-time dosimetry and setups for in-vitro cell radiobiology.

Results: The main scientific results of onCOOPtics are (i) the optimization of laser based ion beam generation, in particular the development of novel and highly reliable techniques for direct manipulation of the ion energy spectrum and spatial distribution; (ii) the development of devices for a real-time physical characterization of laser accelerated charged particle pulses; (iii) the first systematic in-vitro studies of the RBE of laser driven electron beams, (iv) the production of proton beams with energies up to 12 MeV; (v) the prediction of an enhancement of proton energies by targets consisting of stacked ultrathin (~100 nm) foils.

Conclusions: If a clinical laser based accelerator for protons or ions will be feasible at all, the development of this technology is expected to require intensive research in the upcoming 10 years. Among other groups worldwide the the partners in the onCOOPtics project have taken the first successful steps on this risky way.

Supported by the German Federal Ministry of Education and Research (BMBF), grant no. 03ZIK445.