The external beam radiotherapy research community is currently experiencing an exciting time: experimental evidence is growing, supporting the evidence of a considerable normal tissue sparing effect when treatments are delivered with dose rates much larger (100 times or more) with respect to the conventional ones. If confirmed, this so-called `FLASH effect' has the potential to re-shape the future of radiation treatments especially with charged particles, with a significant impact on many oncology patients.
The DEARS project addresses one of the main challenges posed by this potential revolution. The potential of FLASH delivery of electron beams can be evaluated only by means of dedicated MonteCarlo simulations carried out using software tools, currently missing, that are capable of handling the FLASH treatments planning. The development of the needed algorithms and software tools is mandatory to carry out a detailed study on the improvements with respect to standard radio therapy and enable clinical applications. In addition, to improve the experimental knowledge of the FLASH effect new beam monitoring and dosimetry techniques are needed to overcome the saturation problem present in the standard techniques.
Within the Scienze di Base e Applicate per l'Ingegneria department of "Sapienza" university, the knowhow and expertises needed to make a step forward in the implementation of software tools needed for the simulation and treatment optimization tasks are currently available. Same holds for the beam monitoring task: DEARS proponents have already built a prototype detector for FLASH beams monitoring purposes and will use the preliminary results to finalise the monitor geometry and maximise its performance. Such contribution can be seen as a fundamental step towards the FLASH enabling technology.
The DEARS deliverables will place on solid grounds the future steps made when aiming for the FLASH effect confirmation or disprove and its possible clinical implementation.
The DEARS project is ambitious. The potential impact of the FLASH delivery of EBRT is driving the interest of the international research community, and the time factor is crucial. This is the right time to perform the studies proposed within DEARS and address the fundamental questions that are still open. The key aspects that guarantee the success of DEARS are the knowhow of the manpower involved in the project and the research network that the proponents have already built in the field.
The scientific impact of DEARS is not strictly related to the confirmation of the FLASH effect. While performing the research and implementing the necessary steps to bring the FLASH technology to a level compatible with the clinical implementation, the related monitoring technologies as well as the treatment planning tools will be developed and brought one step ahead improving the treatment efficacy even in standard conditions.
To have an implementation of the FLASH approach in clinical centres we do not just need the proof of principle that the effect exists, but also need to develop the technology capable of delivering such beams with the level of control and precision required inside the treatment rooms. Modern RT is a very active research field, in which the quest for more compact accelerators capable of achieving high dose rates and better beam delivery technologies that could allow a more flexible coverage of the clinical target volume is constant and reckless. This effort is constantly driving the research and development activity of the scientific community and of the companies that provide the needed clinical solutions to be implemented in the treatment centres.
DEARS addresses two key questions related to the FLASH therapy understanding and implementation in the clinical environment and in both ways the pursued approach is novel. Concerning the beam monitoring, the use of a detector using the air fluorescence is novel by itself. Such technique has never been implemented before for such applications and its potential to RT and PT is now becoming interesting in view of the very high intensities expected in the FLASH regime. The proponents experience in building and testing novel detector for monitoring applications in particle therapy will be particularly important in ensuring that the real potential of the technique will be extracted and characterised. Concerning the evaluation of the FLASH potential optimising EBRT plans including a modelling of the normal tissue sparing due to the very high dose rates, within DEARS a new approach will be pursued. The dose absorbed by the tissues will be computed using state of the art simulation software for medical applications and an optimisation code, developed at SBAI by the proponents, will be employed to compute the fluence of each particle beam to achieve the target goal inside the tumour while properly sparing the organs at risk. Such minimisation problem calls for novel strategies and requires parallel computing solutions. The proponents have developed the core algorithms needed for such task and software will be tested against real cases provided by the CNAO and APSS treatment centres.
One of the pillars of the Horizon2020 programme is the ¿Health, Demographic Change and Wellbeing¿ challenge. In the current Horizon Europe initiative among `Cluster 1: Health¿ we can find the `Cancer¿ mission area. The DEARS project aligns perfectly with these research interests and goals at european and, more generally, at global level. While the efficacy of conventional Radio Therapy and Particle Therapy treatments is steadily improving due to the constant research and development in the field, it is also true that there are some known limitations of the current therapies that call for novel solutions to broaden the impact and improve the efficacy and availability of deep seated radioresistant tumours treatments.
In that respect, the DEARS project is timely and addresses the crucial questions that have the potential of enabling a new powerful technology to treat deep seated tumours. The project goal nicely fits the landscape of the Horizon research priorities, making a significant contribution to the specific cancer mission area. Among the objectives of DEARS we have the development of novel beam monitoring technologies as well as the tools for an efficient planning of the treatments. The reach of the DEARS program will depend, for sure, on the size and effectiveness of the normal tissues sparing effect of very high absorbed dose gradients typical of the so-called FLASH irradiation. If confirmed, these effects have the potential to revolutionize the EBRT field. But even if in the end the size of the effect will turn out to be reduced, the technological advances delivered by DEARS will significantly help the research community in moving forward in the ¿development of health technologies¿ to ¿mitigate health risks¿ in the population (goals of Horizon Europe initiative).