Photo: Experiment at the FZD's high-power laser
The high-power laser at the FZD
generates protons, accelerating
them on a very short scale of less
than ten micrometers;©OncoRay

Today, accelerated hydrogen and carbon ions are mainly used to treat inoperable tumors in organs like the brain and bone marrow, which are sensitive to radiation therapy. A new technology for this kind of treatment is developed by researchers of the OncoRay center in Dresden and of the research center Forschungszentrum Dresden-Rossendorf (FZD): in their concept the ion beams are accelerated by a compactlaser, and not in "normal" accelerators.

The Dresden OncoRay center, which is carried by the research center Forschungszentrum Dresden-Rossendorf (FZD), University Hospital Dresden and TU Dresden, now achieved an important step towards compact radiation facilities for cancer treatment.
The high-power laser DRACO at the FZD generates protons, accelerating them on a very short scale of less than ten micrometers (which is about one tenth of the thickness of a single human hair). For their current results, the team of researchers led by Doctor Ulrich Schramm (FZD) and Doctor Jörg Pawelke (OncoRay) irradiated cancer cells with protons, i.e. hydrogen atoms where the electron is missing.

The scientists are also investigating the impact of radiation on cells under controlled conditions, for which they developed a special device enabling them to precisely measure the dose of the irradiated cells. The dose of the irradiations at the FZD ranged between 1.5 and 4 gray - an area particularly relevant for clinical application of proton beams. What is more, the energy of the laser accelerated ion beam is high enough for the first time for the beam to be able to penetrate into tissue, but also into other materials, enabling exact dose detection. Up to 20 mega electron volts were achieved in the experiments.

The advantage of accelerated ion beams is that they have their highest impact in the tumor and, thus, have a better ability to spare healthy tissue. Today, more than 60 percent of cancer patients undergo radiation therapy. While, in traditional therapy, a considerable part of the energy of photon beams generated in modern clinical linear accelerators is emitted on their way through healthy tissue, ion beams can be stopped right in the tumor with utmost precision, where their damaging impact is released on all tumor cells.

This new method was successfully tested in the heavy ion therapy project at GSI, Darmstadt, among other things. About 400 patients were treated and about 70 percent of them were cured. FZD scientists collaborated in this project and are also significantly involved in the Heidelberg HIT center.; Source: Forschungszentrum Dresden-Rossendorf e. V.