The 4^th workshop on Very High Energy Electron Radiotherapy (VHEE-RT) was held at the Cockcroft Institute, Daresbury Laboratory, UK from 15^th – 17^th of September 2025. The inaugural workshop was held at the Cockcroft Institute in 2017, with 2^nd one at CERN in 2020 and 3^rd one at DESY, Hamburg in 2023. This in-person workshop was attended by more than 90 delegates, with 26 from the UK, 53 from Europe, 6  from Asia and 7 from the USA.  The workshop was chaired by Prof Deepa Angal-Kalinin, ASTeC, Cockcroft Institute and Prof Roger M. Jones, University of Manchester, Cockcroft Institute. 

The workshop served as a forum for accelerator physicists, clinicians, medical physicists, and industrialists, and allowed cross-fertilisation of ideas from around the world, and to review the latest developments in the field, to exchange ideas and discuss cutting-edge topics. The workshop covered presentations from existing and planned conventional (RF based) and novel acceleration (laser wake field) facilities where R&D for VHEE and FLASH RT is carried out, status and challenges in the fields of radiobiology, dosimetry, treatment planning and steps towards making VHEE (and VHEE with FLASH) radiotherapy a new modality in a potential clinical setting. The vibrant scientific programme was put together by a 22-member international scientific programme committee, which also included dedicated sessions on industry and presentations by PhD students. Early career researchers also presented their work in a dedicated poster session. The dinner took place at Rowton Hall and here the 5-member committee awarded prizes to the winners of the poster competition: Katie O'Shea, Joel Valerian, Louis Kunz for outstanding work in medical physics, machine design, and biology respectively. 

The workshop was endorsed by ICFA and was sponsored by IoP Particle Accelerators and Beams group, the Cockcroft Institute, ASTeC/STFC, LumiTron Technologies, ScandiNova, THALES, SIT. ​

Right to left: Poster prize winners Louis Kunz, Joel Valerian, Katie O'Shea, and workshop co-chairs Prof Roger M. Jones and Prof Deepa Angal-Kalinin.