The ESTRO community is deeply saddened by the loss of Ben Mijnheer, a prominent figure in the field of medical physics. Ben made remarkable contributions to ESTRO and the broader scientific community. His work was instrumental in the transition from 2D to 3D radiotherapy and pioneering IMRT. Beyond his research, he actively engaged with ESTRO, fostering dedicated meetings for physicists and co-chairing the Guidelines Committee. As a respected faculty member and editor of several ESTRO booklets, he shared his expertise in radiation physics and conformal techniques. His legacy will continue to influence and drive the field forward for many years to come. In 2016, Ben received the ESTRO Lifetime Achievement Award, a tribute to his remarkable impact.

Below, you will find a few testimonies from colleagues and friends in the medical physics and radiation oncology community who have worked with Ben. You may contribute to these testimonies by writing to communications@estro.org.

You can read the interview he gave to the ESTRO Newsletter when he received the Lifetime Achievement Award in 2016 at ESTRO 35 here.



“Ben was not only a brilliant medical physicist but also a mentor and advocate for the next generation of professionals. His kindness, willingness to share knowledge, and dedication to improving patient care through innovative solutions were truly inspiring. “

Matthias Guckenberger, ESTRO President

Anna Kirby, ESTRO Past-president

Barbara Jereczek-Fossa, ESTRO President-Elect


“I would like to thank Ben for all his contributions to improve the quality of RT treatments. In particular all his work on in vivo dosimetry starting with point detectors to the use of EPID and 3D dose reconstruction. Before meeting him in person I had read all the papers on in vivo dosimetry and they were key in my career. I still remember the first time I met him in a EU meeting in Prague (quite many years ago), I was impressed by his kindness and by his willingness to solve any doubt for younger colleagues, never making anyone feel not knowledgeable. I keep only good memories of any interaction that I have had with him during the years. All the good times in Barcelona when he came for our course on in vivo dosimetry, ESTRO meetings, and the gift he made me when he agreed to be interviewed for EFOMP news. “

Núria Jornet
Past chair of the ESTRO Physics comittee

“The role of physics in Radiation Oncology has always been a crucial one, but it has also taken several strong advocates over the years to ensure that this is well understood. Ben was indeed one of those advocates. The ESTRO physics committee has gone from strength to strength and one of the most effective current activities is the physics workshops. These were put in place to fill the void when the Biennial meetings, which he helped to set up, came to an end. That interaction of physicists to present, discuss and work together was sorely missed and now we approach the 7th workshop and the other disciplines have taken the initiative and want to start this too.

Personally I remember very well my first activity at ESTRO which was on the IMRT QA booklet. I was young and unsure as to what I could contribute, but Ben was very welcoming and open minded and we created a really nice publication. This was the beginning of my ESTRO journey and I had a very nice impression of the work that physicists could do together. I also was completely bitten by the bug of working with physicists across Europe, which I know from his EFOMP interview, is something which he enjoyed too.

So, I would like to thank Ben, both personally and from the physics committee and wider community for all that he has done for medical physics, for ESTRO and for our patients.”

Catharine Clark

Past chair of the ESTRO Physics Committee and Chair of Professions and Partnerships Council


“Thanks for all Ben.”

Tommy Knoos

Past chair of the ESTRO Physics Comittee and Radiotherapy & Oncology Editorial Board member

David Thwaites

Past chair of the ESTRO Physics Comittee and Radiotherapy & Oncology Emeritus Physics Editor


“It was always a pleasure to work with Ben on a number of different projects, he was so willing to share his knowledge and expertise.”

Mary Coffey
Chair of the ROSEIS Working group


“The ESTRO Physics Committee 2024 is grateful to Ben for all his contributions to the ESTRO Physics activities.”

Daniela Thorwarth

Charlotte Robert

Wouter van Elmpt

Cristina Garibaldi

Coen Hurkmans 

Victor Hernandez 

Christian Richter 

Kathrine Roe Redalen

Åsa Carlsson Tedgren

Tomasz Piotrowski

Jenny Bertholet

Marianne Aznar

Núria Jornet

Dietmar Georg

Ludvig Muren

Catharine Clark