A study led by the Research Group in Radiation Oncology and Medical Physics at the Girona Biomedical Research Institute Dr. Josep Trueta (IDIBGI) and the Catalan Institute of Oncology (ICO) in Girona proposes a new strategy for planning radiotherapy treatments using advanced calculation algorithms. Specifically, the Girona team has developed a tool that is incorporated into the radiotherapy planning system and allows for traditional reporting of doses from these new algorithms, which are now sensitive to the biological tissue composition of the affected area. Additionally, they have, for the first time, evaluated the use of these algorithms in robust optimization, currently the most advanced technique in treatment planning, which accounts for small variations in tumour positioning that can occur in each session. These are two recent innovations which, if applied separately, might in some cases require starting from scratch and disregarding accumulated clinical experience.
This new system has been implemented in a commercial treatment planner and successfully applied to a first group of patients, comparing the resulting treatment plans with those generated through robust optimization. Both methods produced compatible results, and the conclusions were published in the journal “Radiotherapy and Oncology”. Therefore, the tool developed by the Girona researchers allows clinicians to maintain their usual protocols while benefiting from the precision of the new algorithms and increasing patient safety.
Radiotherapy planning systems have evolved significantly in recent years. One of the most recent advancements is the development of advanced algorithms that incorporate a new variable in the calculation of radiation dose. It is the specific composition of the patient’s tissues, a factor that is added to the tumor’s location and shape. This improvement is especially relevant in cases where the area to be irradiated includes high-density tissues, such as bones or metal implants, and it poses new challenges to traditional dose calculation criteria, which apply a homogeneous irradiation to the entire treated area.
Adding to this is robust optimization, a technique that dispenses with the millimetre-scale safety margin traditionally applied around the tumour to ensure treatment coverage. Instead of applying such a margin, this method considers the small uncertainties in tumour position that can occur during each session and incorporates this information directly into the treatment design process, thereby minimizing risk to nearby healthy organs. Robust optimization thus accounts for all uncertainties in the optimization of the irradiated area.
The development of this new tool within the planning software acts as a bridge between classical planning and the new algorithms. “We’ve found a way to more accurately calculate the dose a patient receives by integrating both innovations, without losing the knowledge accumulated over years with traditional systems,” explains Dr. Diego Jurado-Bruggeman, medical physicist and lead investigator of the study. “This allows us to harness the potential of advanced algorithms without radically changing clinical practice, which benefits any radiotherapy patient, regardless of their pathology.”
The benefits of this new methodology are direct for patients. It enables more precise calculation of the actual dose received by each point of their body, considering the specific tissue composition, while maintaining the safety and efficacy criteria of clinical protocols. This can reduce side effects and improve tumour control. “From the patient’s perspective, we are calculating more accurately than before. At the same time, we’re maintaining the type of radiation we already know, both for tumour control and for protecting at-risk organs,” adds Dr. Jurado.
This work represents a first step toward the development and implementation of a new, more precise and safer planning model. The research was carried out in collaboration with a team from RaySearch Laboratories (Sweden), a leading software company in the field, and it opens the door to further advances in personalized care for oncology patients.
Reference article: Jurado-Bruggeman D, Angerud A, Fredriksson A, Muñoz-Montplet C. On the PTV homogeneity objective in the era of photon advanced dose calculation algorithms: Bridging robust and PTV-based planning. Radiother Oncol. 2025 Apr 4;207:110878. doi: 10.1016/j.radonc.2025.110878. Epub ahead of print. PMID: 40189149.
