New approaches for cancer therapy: First tumor treatment with radioactive ion beams

The research project “BARB – Biomedical Applications of Radioactive Ion Beams” funded by a prestigious ERC Advanced Grant to Professor Marco Durante, head of the Biophysics Department at the GSI Helmholtzzentrum für Schwerionenforschung, has reached an important milestone: the first treatment of an animal tumor with radioactive ion beams has been demonstrated and published in Nature Physics. The study marks a decisive step towards the further development of particle therapy and is based on intensive collaboration between different GSI departments and FAIR pillars and with the LMU Department of Medical Physics, which contributes to the BARB project as Associated Partner with a team led by Professor Katia Parodi.

BARB and the recently published paper are centered on the forward-looking idea of using radioactive ion beams (RIB) for simultaneous treatment and imaging. This approach could significantly reduce what is known as range uncertainty—one of the greatest challenges in particle therapy. The work now presented demonstrates for the first time the feasibility and great potential of the concept under realistic conditions.

“Particle therapy is growing rapidly and is possibly the most effective and precise radiation therapy technique,” says Durante. “However, its application is still limited by technical constraints such as inadequate image guidance. The new idea of using the same beam for treatment and for imaging during treatment could pave the way for even more precise and diversified applications. Improving accuracy is a key to expanding the applicability of particle therapy.” This could also allow for better treatment of metastases or tumors near critical structures and small targets in non-cancerous diseases, such as ventricular ablations for cardiac arrhythmias.

Localize the ion beam in the body

A detector developed at LMU plays a key role in BARB, enabling the precise localization of the ion beam within the body. The international and interdisciplinary team of Katia Parodi, in collaboration with Professor Taiga Yamaya's laboratory (QST-Chiba), has developed a high-resolution and highly sensitive in-beam positron emission tomography (PET) scanner for small animals. The system was originally developed as part of Professor Parodi’s ERC Consolidator Grant “SIRMIO — Small animal proton irradiator for research in molecular image-guided radiation-oncology“ to monitor the radiation-induced activity of proton beams and has been further developed in recent years as part of the BARB project to monitor radioactive ion beam treatments in real time. “The BARB project marked an important milestone for the first in vivo application of advanced instrumentation that we have developed over the past years at LMU to open new frontiers in high-precision image-guided small animal radiation research”, comments the LMU project lead Katia Parodi.

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“Our work focused on real-time in-beam PET data acquisition and image reconstruction. This contributed to the first successful demonstration of tumor control using image-guided radioactive ion beam therapy in mice,” says co-first author Giulio Lovatti, who analysed the PET data of the Nature Physics paper as part of his doctoral thesis in physics at LMU. BARB impressively demonstrates how applied nuclear physics can provide direct impetus for medical applications, according to the researchers.

“We conclude that image-guided particle therapy with exotic beams is feasible, safe, and effective,” the researchers report. Further short-lived isotopes will be investigated in the future, which researchers hope will provide a stronger signal and faster feedback during treatment. “Our preclinical results demonstrate the feasibility of RIB radiation therapy and thus point the way toward future clinical applications of radioactive ion beams,” says BARB project leader Professor Marco Durante.

Daria Boscolo, Giulio Lovatti, Olga Sokol et al.: Image-guided treatment of mouse tumours with radioactive ion beams. Nature Physics 2025