FLASH proton therapy: planning and delivery challenges - are we close to the clinics?

by Alberto Taffelli (Istituto Nazionale di Fisica Nucleare)

Thursday 3 Apr 2025, 14:00 → 15:00 Europe/Rome

Sala riunioni 250 (INFN - Pisa)

Abstract: The discovery of the FLASH effect in radiotherapy has sparked an immense collaborative effort within the scientific community to tackle the new challenges and opportunities it presents. This effect occurs when radiation is delivered at ultra-high dose rates (UHDR >40 Gy/s), and it has been observed to differentially damage irradiated cells — effectively targeting tumor cells while sparing healthy ones. Although the underlying mechanism of the FLASH effect remains unclear, new approaches to dose delivery and treatment planning are being actively explored, with researchers patiently awaiting mechanistic insights.

Among the various radiotherapeutic techniques, in the next future proton therapy is expected to stand out as the most promising candidate method to deliver UHDR treatments for deep-seated tumors, maximizing the potential benefits of the FLASH effect. However, significant challenges remain in adapting proton delivery systems to operate under FLASH conditions, as well as in optimizing proton therapy treatment planning, where a clear definition of the key metrics is still lacking.

I hereby present an overview of recent advances in the field of FLASH proton therapy and how research and clinical practice have leveraged the FLASH effect in recent years. In this context, the Trento section of INFN (TIFPA) is playing a pivotal role, supported by the Trento Proton Therapy Center (APSS). An experimental FLASH proton beam is now available, and initial radiobiological experiments have already been conducted. Research on proton FLASH treatment planning is also progressing, paving the way for future clinical applications.