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02.11.2009 | Heidelberg Ion Therapy Centre (HIT) has opened

Developed at GSI, the novel cancer therapy facility now started routine operation

G. Otto/GSI Helmholtzzentrum für Schwerionenforschung GmbH

The treatment space at the GSI accelerator

G. Otto/GSI Helmholtzzentrum für Schwerionenforschung GmbH

Linear accelerator


On November 2nd, the Heidelberg Ion Therapy Centre (HIT) celebrated its opening. Developed at the GSI Helmholtzzentrum für Schwerionenforschung, the novel ion beam cancer therapy is now available for a large number of patients. So far, patients had been treated solely at the GSI treatment facility. Ion beam therapy is precise, highly effective and very gentle on the patient. HIT is operated by the Universitätsklinikum Heidelberg (University Hospital Heidelberg), where a special building with a floor space of 60 x 80 meters was constructed to hosts the new therapy facility. Its accelerator facility and irradiation technology were developed and built by GSI scientists and engineers. The ion beam cancer treatment at HIT is one of a kind. Currently, the only other country offering ion beam cancer therapy is Japan, however, with a less effective irradiation technique. In the scope of a licence agreement between the GSI Helmholtzzentrum and Siemens AG, two more facilities modelled on HIT are under construction in Marburg and Kiel, Germany.

From now on, a yearly number of 1,300 patients can be treated at HIT. Since 1997, 440 patients, most of them with tumours at the base of the skull, have been treated with carbon ion beams at the GSI facility. Clinical studies proved the success of the therapy, documenting a cure rate of up to 90 percent. Ion beam treatment is now an accepted therapy with health insurance providers refunding the costs.

The heart of HIT is an accelerator facility tailored to therapeutic use and adapted to medical routine operation. The HIT accelerator is significantly smaller than the therapy facility used at GSI. The GSI accelerator spans several hundred meters and is mainly used for heavy ion experiments in fundamental nuclear and atomic physics research. Before administering the first treatment, GSI scientists had carried out fundamental research on the radiobiological effects of ions on cells for several decades, developing an irradiation technique that allows targeting the tumour with the ion beam in the most precise and safe way.

“Since the 1970s, we have systematically examined the effects of ion beams on over 100,000 cell cultures, always looking to optimize ion therapy. When we first started, most people didn’t think it possible that we could develop the technology to make the excellent biological-medical qualities of ion beams useful for therapy. We succeeded thanks to the interdisciplinary cooperation of nuclear and atom physics, radiobiology and radiation therapy, accelerator physics, computer science and many more fields”, says Gerhard Kraft, initiator and pioneer of ion beam therapy and holder of a Helmholtz professorship in the field of biophysics at GSI. ”With the opening of the HIT, the vision professor Kraft and his team had 40 years ago finally comes true: routinely treating patients with up to now incurable tumours with the help of ion beams. This form of therapy offers an increased chance of curing the cancer with shorter treatment cycles and fewer side effects. Ion beam therapy is a great example for a successful transfer of fundamental research to applied technology for the benefit of mankind”, says Horst Stöcker, scientific director of the GSI Helmholtzzentrum and vice president of the Helmholtz-Gemeinschaft.

HIT comprises an accelerator facility with a 5 meter long linear accelerator and a ring accelerator with a diameter of 20 meters. Three treatment spaces are located adjacent to the accelerators, two of which are a continued development of the technology used at GSI. The third treatment space features a rotating ion beam guidance system, a so-called gantry. This gantry is a direct advancement of the prototype developed at GSI. The gantry allows aiming the ion beam at the patient’s tumour at any angle, thus enhancing the treatment options tremendously. HIT uses ions, i.e. positively charged carbon or hydrogen atoms for the treatment.

Ion beams penetrate the body and exert their full impact deep within the tissue, where they hit a spot the size of a pinhead. To reach the tumour tissue, the ions are accelerated inside the accelerator facilities to about three quarters of the speed of light. That is almost 1 billion kilometres per hour. The ion beams are steered with precision so exact that a tumour the size of a tennis ball can be irradiated point by point with millimetre accuracy. The surrounding healthy tissue remains mostly unaffected. Therefore, this method is particularly suited for treating deep-seated tumours that are close to vital or important organs like the brain stem or the optic nerve.

The development of ion beam therapy is a joint project of the Universitätsklinikum and the Deutsche Krebsforschungszentrum in Heidelberg, the Forschungszentrum Dresden-Rossendorf, and the GSI Helmholtzzentrum für Schwerionenforschung.

Development of the Novel Therapy

The GSI Helmholtzzentrum has been conducting fundamental research in the field of radiobiology, nuclear physics and accelerator technology for therapeutic use since 1980. In 1993, the construction of the therapy facility at GSI, Darmstadt, began. Since 1997, approx. 440 patient have been treated by the teams of the collaborating partners GSI Helmholtzzentrum für Schwerionenforschung, Universitätsklinikum Heidelberg, Deutsches Krebsforschungszentrum in Heidelberg, and Forschungszentrum Dresden-Rossendorf. At the same time, plans were made for the clinical facility HIT, to introduce ion beam therapy as a regular component of patient care. HIT represents a direct transfer of technology from the GSI pilot project.

The GSI pilot project produced the following unique innovations:

  • the raster scan method, allowing a tailored tumour irradiation with a carbon-ion beam
  • an accelerator that permits a quick and active variation in the ion beam’s energy level, thus allowing to adapt the penetration depth inside the tumour
  • a fast control system, safely steering the ion beam inside the patient at millisecond intervals
  • a “biology-based” irradiation plan, calculating the physical dose and biological effect of the ion beam at any given point inside the tumour
  • monitoring of the irradiation through a positron emission tomography (PET) camera, to make sure the beam hits the tumour 
The GSI Helmholtzzentrum für Schwerionenforschung

GSI is a research centre of the Helmholtz-Gemeinschaft in Darmstadt, Germany. It is financed by the German federation and the German state of Hesse with a budget of 90 million euros. GSI’s research goal is to create a comprehensive picture of our surrounding nature. In this spirit, GSI’s over 1,000 employees operate a one-of-a-kind accelerator facility for ion beams. More than 1,000 guest scientists from all over the world use the accelerator facility for their fundamental research. GSI’s research program comprises a broad range of fields from nuclear and atom physics to plasma and materials research to biophysics.

GSI’s most prominent advancements are the discovery of new chemical elements and the development of a novel cancer therapy using ion beams. With these cutting-edge innovations and many more scientific novelties, GSI is a global leader in ion beam research. With the construction of the new international accelerator facility FAIR (Facility for Antiproton and Ion Research) at GSI, the centre will be able to continue its world-class research. The new FAIR facility will give researchers the opportunity to conduct a variety of experiments, with which they hope to gain new insights into the structure of matter and the evolution of the universe.

The treatment space at the GSI accelerator
Linear accelerator
The image shows the treatment space at the GSI accelerator, where the clinical studies on tumour therapy with heavy ions are conducted. In order to ensure maximum precision, the patient's head is fixated.
Inside the GSI's 120 meter long linear accelerator.
G. Otto/GSI Helmholtzzentrum für Schwerionenforschung GmbH
G. Otto/GSI Helmholtzzentrum für Schwerionenforschung GmbH