In Bern high-energy physics shares proton beams with the hospital

A joint venture bringing together public institutions and private companies is building a new facility on the campus of Inselspital, Bern’s university hospital. The facility will host a cyclotron for the production of radiopharmaceuticals for use in PET as well as in multidisciplinary research laboratories for the development of new products for medical imaging. The Laboratory for High Energy Physics (LHEP) of Bern University, which is deeply involved in the project, will have access to a dedicated beam line and specialized labs.


Construction of the new facility is ongoing at Bern's University Hospital, where the cyclotron will be installed.

The first Bern Cyclotron symposium will take place on 6 and 7 June this year. The event is being organised by LHEP in collaboration with Bern’s Inselspital and will bring together experts – including several from CERN – to promote research activities at the new Bern Cyclotron Laboratory. “The cyclotron will be installed in a dedicated new building, which is under construction on the campus of the hospital. Its main function will be the production of radiotracers for use in PET imaging,” explains Saverio Braccini from LHEP, a senior researcher and the chair of the symposium. “Thanks to the collaboration between the University and the hospital, the building has been designed to host an external beam line, which will be independent from the production activities and fully dedicated to research.”

The role of radiotracers is crucial in PET technology (see box) and a lot of research over the years has gone into finding the most appropriate and effective radionuclide. Physicists have been at the frontline of the research in this field right from the start. One of the main requirements for the clinical use of radionuclides is their life-time, which needs to be relatively short in order to limit the negative effects of radioactivity in the body. However, this also requires these isotopes to be produced in close proximity to the imaging facility. “Today, the most commonly used radionuclide is Fluorine-18, whose life-time is less than two hours. With the new cyclotron, we will be able to produce Fluorine on site but, thanks to the external beam line, we will also be able to test other isotopes, which might be used not only for diagnostics but also for therapy,” says Konrade von Bremen, Director of SWAN Isotopen, the company created by the Inselspital and the University of Bern in 2007 to lead the project.

The SWAN Team: K. von Bermen (CEO), S. Braccini (physicist at LHEP), C. Schweinsberg (Radiopharmacist) and C. Dumas (Radiopharmacist)

The layout of the new building is a good illustration of the successful collaboration between the various institutions involved in the project. “The cyclotron and the beam line are being built by the Belgian company IBA and will be installed in the basement of the building, where physicists from LHEP and other institutions will carry out research in a dedicated lab. The first floor will host the radiochemistry and radiopharmacy laboratories, where the isotopes will be chemically synthesised to form the radiotracers that will be injected into the patients. On the second floor, offices and labs will allow multidisciplinary research activities, exploiting the synergies among the stakeholders of our project to the maximum. Finally, the top two floors will host treatment and patients’ rooms,” explains Saverio Braccini. “The possibility to exploit a dedicated beam line for research in medical applications of particle physics is a great opportunity and will also facilitate the training of a new generation of physicists with specific and currently rare competencies,” says Antonio Ereditato, Director of LHEP. “Particle physics has very often produced valuable knowledge and techniques for the benefit of society. With this project we will exploit our expertise for applications in medicine and, at the same time, seek to make scientific advances in the field.”

The cyclotron will be shipped to Bern in a few weeks' time, and the first isotopes will be produced towards the end of the year.

The IBA Cyclotron

The IBA Cyclone 18/18 is a dual-source high-current proton cyclotron, specifically designed for radioisotope production. Proton beams of 18 MeV and a maximum intensity of 150 μA can bombard one or two targets simultaneously. The machine features eight out-ports with targets for different radioisotope production. In the configuration chosen for Bern, one out-port will direct the beam on a 6 m beam line ending in a separate bunker.


How PET works

Positron Emission Tomography (PET) is a medical imaging technique that can help detect cancerous cells as well as study other functional processes in the body. The system detects the gamma rays emitted by the recombination of electrons in the body with positrons emitted by the tracer injected into the patient. The technique is widely used in oncology, where the computer-driven image reconstruction maps the matter-antimatter annihilations. Radionuclides used in PET are incorporated into compounds – like Fluorine-18 marked glucose (FDG) – for which tumours are particularly thirsty. Therefore, in those regions, the rate of the positron-electron recombination is higher and the tumour can be detected.


by CERN Bulletin