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discovered_01_2013

COLLABORATION// The HZDR Research Magazine WWW.Hzdr.DE 38 39 set by choosing the particle range in the tissue prior to treatment. This is exactly why radiation oncologists consider proton and ion beams a highly effective anti-cancer weapon. In the case of state-of-the-art X-ray based cancer therapy, refined techniques for optimal irradiation are available. These technologies cannot readily be adopted for particle beams because of their different physical behavior. This status quo is what prompted the ENVISION project. Originally proposed in 2007 by Ugo Amaldi of CERN, the European Nuclear Research Center in Geneva, and Wolfgang Enghardt of the OncoRay Research Center in Dresden, the project has been coordinated by CERN ever since 2010. Scientists from 15 research institutes and one medical technology company are together developing imaging devices and protocols to visualize the invisible particle beam inside the patient’s body. They are exploiting the fact that a proportion of the particles collides with atomic nuclei of the irradiated tissue. Because of the particles’ high speed - they travel at up to 70 percent of the speed of light - nuclear reactions are taking place. This leads to secondary radiation like gamma radiation, fast protons and neutrons; they carry useful information about the radiation’s degree of precision. The researchers are working on a number of topics simultaneously: // Development of radiation detectors that precisely register secondary radiation, in particular its energy and its position of origin. // Design of software capable of calculating from these signals highly informative images and clinically relevant conclusions in real-time for all therapeutic situations – in particular also for tumors that follow the breathing motion. // Integration of this software into the planning of radiation treatment as a prerequisite for "adaptive" particle therapy; deviations from the treatment plan are immediately corrected by adjusting the radiation parameters. HZDR department chair and physicist Fine Fiedler and her former Ph.D. supervisor Wolfgang Enghardt are working closely with five Ph.D. students to find answers to these questions. Says Fine Fiedler: "Our goal is to determine both the range of the protons and the applied radiation dose directly during radiation treatment. A major benefit to us is the close collaboration with the University Hospital and the TU Dresden at the OncoRay Center because it allows us as physicists to directly exchange ideas with experts from the fields of oncology, cancer biology, or computer science. This is very important: After all, ultimately, these devices must prove useful in the clinical context." Therefore Fiedler and her OncoRay colleague Guntram Pausch, who is head of the "In-vivo dosimetry for new types of radiation" group funded by the Federal Ministry of Education and Research (BMBF), make for a great team. Nuclear physics meets medicine Wolfgang Enghardt is the force behind nuclear physics making its way successfully into medical technology, since he is an international expert in this field. As part of the German Heavy Ion Therapy Project, years ago, he developed a PET camera to image the particle beam’s path inside the patient’s body following treatment. Today, Enghardt heads the corresponding part of the ENVISION project and is also the man in charge of the project overall here in Dresden. "Radiation oncologists need images that show how much of a given dose actually ends up at its target destination. But we’re also working towards the implementation of protons as adaptive high precision therapy in the everyday clinical setting. Our new high-tech equipment is supposed to directly intervene in the treatment and make corrections if there are any deviations of the actual beam from the calculated dose or range." Oncologists estimate that some 15 percent of all radiation therapy patients will benefit from particle therapy. The additional devices and techniques being investigated within the frame of the ENVISION project are indispensable. Only they are capable of creating the proper conditions to enable proton and ion beams to destroy the cancer completely while sparing the surrounding healthy tissue as best as possible. Wolfgang Enghardt is a realist: "Ever since 1896, when X-rays were first introduced in cancer therapy, the challenges for physicians, physicists, and engineers have been the same, that is increasing the efficacy and precision of radiotherapy. The ENVISION project, which is funded by the EU through 2014, has yielded cutting-edge physical and technical solutions. A few of these important results may become clinically relevant over the coming years. However, rapid development of accelerator technology, radiation detectors, and IT solutions, will guarantee that, in 10, 20, or 30 years’ time, as long as radiation therapy will continue to exist as a highly effective cancer treatment modality, research on this topic will go on and refined technological solutions will reach the clinical setting." ContaCt _Institute of Radiation Physics at HZDR Dr. Fine Fiedler f.fiedler@hzdr.de _National Center for Radiation Research in Oncology "OncoRay" Prof. Wolfgang Enghardt wolfgang.enghardt@oncoray.de _Research group "In-vivo dosimetry for new types of radiation" Dr. Guntram Pausch guntram.pausch@oncoray.de www.oncoray.de envision.web.cern.ch

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