May 2, 2019 – IBA (Ion Beam Applications SA) recently announced the first Flash irradiation in an IBA proton therapy gantry treatment room at the University Medical Centre Groningen (UMCG) in The Netherlands. This novel technique has the potential to enhance the therapeutic window with a fast and powerful treatment that delivers a high dose of radiation at an ultra-high dose rate.
On March 1, 2019, IBA delivered several Flash irradiations at isocenter in one of the two gantry treatment rooms at UMCG in Groningen, The Netherlands. Results obtained with the current IBA Proteus solution are promising, according to the company, and largely exceed the conditions required to obtain the Flash effect with a dose rate up to 200 Gy/sec.
When compared to radiotherapy delivered at conventional dose rates (1 – 7 cGy/sec), the Flash phenomenon seems to appear when irradiation is delivered with a dose superior to 8 Gy and at a dose rate above 33 Gy/sec in a very short time (less than a second). Researchers theorize that irradiation at very high dose rate causes oxygen depletion in tissues, which renders healthy tissue radioresistant, enabling dose escalation to levels that destroy tumor tissues even in high hypoxia. In other words, healthy tissue seems to better withstand this novel method of irradiation, while the tumor has the same level of sensitivity to Flash irradiation as to conventional treatment.
Hans Langendijk, M.D., Ph.D., chair of radiation oncology, University Medical Centre Groningen, said, “Being the first proton therapy center that has treated patients in The Netherlands, we have the vision that the clinical introduction of new and emerging radiation technologies should be more evidence-based. As the pioneer of the model-based approach for selecting patients for proton therapy in The Netherlands, we look forward to better understand the radiobiological effect of Flash irradiation and predict the benefits and outcomes of Flash therapy for patients.”
The Flash irradiation is highlighted in Science Translational Medicine.
Watch the VIDEO: The Role of the Physicist in Proton Therapy
For more information: www.iba-worldwide.com
November 04, 2025 
