Brachytherapy continues to push the boundaries of innovation in radiation oncology, integrating advanced technologies and refining clinical applications. At ESTRO 2025, the brachytherapy track will showcase cutting-edge research on artificial intelligence-driven treatment planning, electromagnetic tracking, re-irradiation strategies, and the role of brachytherapy as a boost technique.

In this interview, the chair of the brachytherapy track Prof. Dr. rer. nat. Frank-André Siebert shares key trends shown in this year’s submissions highlights must-see sessions—including that on the EMBRACE II study and discusses the future of brachytherapy, from automation to online verification.

What trends have emerged in the brachytherapy-related research submitted for ESTRO 2025?

There is a trend towards the use of modern technology in clinical brachytherapy. We have several abstracts on electromagnetic tracking for various disease sites in the clinical setting. It is very encouraging to see these techniques making the step from research level to clinical applications and further to benefitting patients! The situation is similar with artificial intelligence (AI). The submitted abstracts show that AI can be used for treatment planning as well as for contouring of organs at risk and can be used to optimise the brachytherapy workflow by saving time and increasing consistency.

Are clinical trials a prominent focus in this year’s brachytherapy programme?

A highlight of the brachytherapy/ESTRO programme this year is the study on image-guided, intensity-modulated, external beam radiochemotherapy and MRI-based adaptive brachytherapy in locally advanced cervical cancer (EMBRACE II) in the interdisciplinary track. This study shows the deep integration of brachytherapy into radiotherapy concepts and presents very good results. The data for 1,482 treated cervical cancer patients have been analysed. The treatment consisted of a combination of external beam radiotherapy and brachytherapy in compliance with strict limits and a stringent quality assurance programme. The results are excellent with high rates of long-term disease-free survival and limited G4/5 morbidity.

What advancements or breakthroughs in brachytherapy research should attendees look out for?

At ESTRO 2025, we will see that brachytherapy has reached a very high technical level for almost all treatment sites. The use of 3D-imaging with different imaging modalities is standard, as is the use of adaptive radiotherapy techniques, and accurate and precise treatment planning using modern applicators ‑ and finally, safe treatment delivery. In addition to the well-established standard treatments, I see a trend towards the use of brachytherapy for re-irradiation and a better understanding of brachytherapy as a boost technique. The latter is supported by efforts in radiobiology and applications in dose accumulation between brachytherapy and external beam doses.

What makes the brachytherapy sessions indispensable for radiation oncology professionals?

The brachytherapy track has acted like a magnet to all brachytherapy enthusiasts for many years. As brachytherapy is increasingly melded with external beam radiotherapy, the brachy sessions become increasingly attractive to all radiotherapists and oncologists! Here they see and hear what they need to understand modern radiotherapy in all aspects and how to use this important tool. If anyone is not yet convinced about brachytherapy, they should come to the brachytherapy track sessions and see what great dose distributions and treatment results can be achieved with brachytherapy!

How do you see brachytherapy evolving in the next few years, based on this year's abstracts?

I see brachytherapy becoming more deeply integrated into radiotherapy treatment concepts; I see an increasing application of our GEC-ESTRO recommendations; and I see a trend towards automation through AI and online verification using tracking and in-vivo dosimetry methods.

The question of the future of brachytherapy will be discussed by a panel in the brachytherapy track. For me, this will be a highlight of our brachytherapy programme. Not only well-known brachytherapy experts, but also a patient advocate, a young ESTRO representative and a delegate of the ESTRO board will discuss and try to outline a roadmap for improved clinical application of brachytherapy.

Prof. Dr. rer. nat. Frank-André Siebert

Chair-elect, GEC-ESTRO committee
Medical physicist/head of Medical
Physics Department, UKSH, Campus Kiel
Clinic of Radiotherapy, Kiel, Germany

Chair of the ESTRO 2025 Brachytherapy Track

Late Registration deadline: 2 april 2025

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