The European Society for Radiotherapy and Oncology (ESTRO)
Since their introduction in the 1980s, ESTRO Annual Conferences have become a must in the calendars of radiotherapy professionals not only in Europe, but around the globe. The unique environment of ESTRO events provides a platform for the various scientific disciplines that are essential to radiotherapy: biology, physics, technology and clinical.
This year’s theme is Innovating Radiation Oncology, Together and the event will be held at the Stockholmsmässan in Stockholm, Sweden, from 15 to 19 May.
FLASH Radiotherapy, a Groundbreaking Innovation in Radiotherapy Research
FLASH Radiotherapy is one of the latest innovations to embody the four pillars of ESTRO.
Biology – FLASH Radiotherapy is an innovative radiation technique in which treatment is delivered in a fraction of a second at ultra-high dose rates (UHDR). Using this method, a remarkable biological effect, known as the FLASH effect, can be observed. Pre-clinical studies suggest an enhanced differential response, where damage to surrounding healthy tissue is reduced while maintaining tumor control[i][ii]. The use of Very-High Energy Electrons (VHEE), typically above 100 MeV, is particularly promising, as their deep penetration enables FLASH irradiation of larger and more deeply seated tumors, potentially extending these biological benefits to a wider range of clinical indications.
Physics – The triggering of the FLASH effect depends critically on both dose rate and irradiation time. Delivering the full prescribed dose within milliseconds requires particle beams capable of sustaining ultra-high dose rates with precise temporal control. VHEE beams are especially well suited to this challenge: their high energy allows for stable beam transport and dose delivery at depth, while maintaining the beam intensities required for UHDR conditions.
Technology – Generating particle beams that meet FLASH requirements has driven major advances in accelerator technology over the past decade. Conventional radiotherapy systems, typically operating at dose rates of 1–20 Gy/min, were not designed for UHDR delivery. In contrast, VHEE-FLASH-capable accelerators are being developed to deliver ultra-high dose rates while maintaining beam stability, precision, and safety.
Clinical – FLASH Radiotherapy remains largely in the pre-clinical and early clinical research phase, with ongoing studies aiming to confirm the reproducibility and safety of its observed benefits. The introduction of VHEE-FLASH systems is expected to play a pivotal role in clinical translation, as their ability to treat deep-seated tumors addresses a major limitation of current FLASH approaches. Enabling the clinical translation of FLASH radiotherapy and supporting the transition from laboratory to clinic lies at the heart of THERYQ’s mission.
THERYQ, Pioneers in FLASH Radiotherapy
THERYQ specializes in the development of FLASH Radiotherapy devices, with a view to pioneering the clinical application of this innovation. For over a decade, THERYQ’s teams have partnered with various leading cancer research centers in collaborative FLASH research projects.
This year, don’t miss abstract presentations that stem from our research collaboration with Gustave Roussy, (Villejuif, France):
Saturday, 16 May 2026
10:30–11:30 | Beam to biology: Advancing clinical translation of FLASH | A10 | Track: Physics
Investigating Superoxide Radical Yield Under Ultra-High Dose Rate Irradiation: Effects of Beam Parameters on Water Radiolysis
Presenter: Aashini Rajpal (France)
Presentation No.: 786
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10:45–11:15 | Poster Area | Poster Highlights | Track: Physics
Towards Standardized Quality Assurance for Non-Conventional Beams: A Preliminary Framework for the FLASHKNiFE™ UHDR Electron Accelerator
Presenter: Elena Agostoni (France)
Presentation No.: 820
Sunday, 17 May 2026
11:15–11:30 | Poster Area | Poster Highlights | Track: Physics (Machine Learning & AI Algorithms)
Developing a Machine Learning-Based Digital Twin for an Electron FLASH Radiotherapy LINAC
Presenter: Johan Leygonie (France)
Presentation No.: 575
Monday, 18 May 2026
08:45–09:45 | Poster Area | Poster Highlights | Track: Radiobiology
Impact of Dose Fractionation and Pulse Splitting on the FLASH Effect in Ultra-High Dose-Rate Electron Irradiation
Presenter: Amina Joudat (France)
Presentation No.: 2971
Discover the official ESTRO 2026 Programme here.
If you would like to meet with our team in Stockholm, feel free to reach out to the team here.
Sources
[i] 1. Favaudon, V., Caplier, L., Monceau, V., Pouzoulet, F., Sayarath, M., Fouillade, C., Poupon, M., Brito, I., Hupé, P., Bourhis, J., Hall, J., Fontaine, J., & Vozenin, M. Ultrahigh dose-rate FLASH irradiation increases the differential response between normal and tumor tissue in mice. Science Translational Medicine, 6(245) (2014). https://doi.org/10.1126/scitranslmed.3008973
[ii] Bourhis, J., Sozzi, W. J., Jorge, P. G., Gaide, O., Bailat, C., Duclos, F., Patin, D., Ozsahin, M., Bochud, F., Germond, J., Moeckli, R., & Vozenin, M. Treatment of a first patient with FLASH-radiotherapy. Radiotherapy and Oncology, 139, 18–22 (2019). https://doi.org/10.1016/j.radonc.2019.06.019