Currently, new treatment facilities for radiation therapy with ions are built all over the world. These particles destroy cancer cells and have a better ability to spare the surrounding healthy tissue than other techniques. Today, accelerated hydrogen and carbon ions are primarily used to treat inoperable tumors in organs such as the brain and bone marrow, which are sensitive to radiation therapy.
Conventional proton and ion accelerators are large and expensive, which is why the new therapy making use of accelerated proton and ion beams can only be applied in a few clinics such as the Heidelberg Ion-Beam Therapy (HIT) Center. However, there is a big worldwide interest in compact and flexible facilities for proton and ion acceleration for therapy, as experts expect the proof of the advantages of proton and ion therapy for an increasing group of different cancer diseases in the future leading to widespread clinical application.
The Dresden OncoRay Center, which is carried by the research center Forschungszentrum Dresden-Rossendorf (FZD; Germany), University Hospital Dresden, and TU Dresden, now achieved an important step towards compact radiation facilities for cancer treatment.
The high-power laser DRACO (Dresden laser acceleration source) at the FZD generates protons, accelerating them on a very short scale of less than 10 μm. For their current findings, the team of researchers led by Dr. Ulrich Schramm (FZD) and Dr. Jörg Pawelke (OncoRay), irradiated cancer cells with protons.
The scientists are also investigating the impact of radiation on cells under controlled conditions, for which they developed a special device enabling them to measure precisely the dose of the irradiated cells. The dose of the irradiations at the FZD ranged between 1.5 Gy and 4 Gy–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 MeV were achieved in the experiments.
Sixty percent of cancer patients receive traditional radiation therapy. 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% 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 (Germany), among other places. About 400 patients were treated and about 70% of them were cured. FZD scientists collaborated in this project and they are also significantly involved in the Heidelberg HIT center.