New technique to measure blood radiation

The University of Navarra has developed a new personalized method to accurately quantify the radiation dose that receives blood during cancer radiotherapy treatments, which ensures that it represents an advance towards a “more personalized, preventive and safe” cancer medicine.

The investigation has been led by Marina García-Cardosa, Researcher of the Medical and Biophysical Physics Group (Physmed) of the Faculty of Sciences, and recognized by international institutions. The study has been carried out in collaboration with doctors and researchers at Cancer Center University of Navarra.

Historically, radiotherapy has focused its efforts on avoiding damaging fixed organs close to the tumor, but the blood – a mobile and vital tissue that runs through the entire body – had been out of the usual dosimetric calculations. The doctoral thesis defended by Dr. García-Cardosa proposes to reverse this omission with an innovative approach: treat blood as a “organ at risk” and adapt the treatment to protect it when clinically viable.

“Each blood cell that crosses a radiation field receives a small amount of energy. Although this dose seems low, its effect can accumulate throughout the treatment and affect the immune system or cause hematological toxicity,” explains the researcher.

Flip-Heados

The method, called Flip-Hedos, integrates specific anatomical information of the patient, real blood circulation patterns and data from the radiotherapy treatment plan to precisely simulate how and how much blood is radiated. Thanks to its multidisciplinary approach -combining medical physics, biophysics, oncology and engineering -this technology allows to calculate personalized scenarios and evaluate the accumulated exposure in prolonged treatments.

The results reveal that factors such as Tumor proximity to large blood vessels, The type of radiotherapy applied and the variability of each patient’s cardiac spending (amount of blood pumped by minute), directly influence the irradiation of the blood and, consequently, in their immune response.

“The immune system is especially sensitive to radiation. Fundamental cells such as lymphocytes – found to coordinate the defense of the organism – can be affected even by very low doses. If a significant amount of these cells is damaged, the body’s ability to respond to infections, inflammations or even the tumor itself, can be compromised. This aspect acquires even more importance in treatments that combine radiotherapy with radiotherapy Immunotherapy, “explains García-Cardosa.

According to the University of Navarra, the participation of the Cancer Center University of Navarra It has been fundamental to integrate the clinical experience in advanced oncological treatments. In addition, the research has had the advice of Professor Harald Paganetti, international reference in Medical Physics of Massachusetts General Hospital and Harvard Medical School.

Future applications

This work has been distinguished as one of the best oral communications by the European Society of Radiotherapy and Oncology (Estrus) in Austria (May 2025) and in specialized congresses such as Radiation Research Society Conference in the United States (September 2024) and by the Spanish Society of Medical Physics at the national level (May 2025). In addition, part of their results have been published in the scientific journals ‘Radiation Physics and Chemistry’, ‘Physics in Medicine & Biology’ and ‘Clinical Cancer Research’.

Regarding their potential in oncological treatments, the authors indicate that the Flip-Hedos framework could be useful to simulate the distribution of drugs or radiopharmaceuticals, as well as to evaluate new radioprotection and hematological toxicity strategies. “Thinking about blood as a dynamic organ to protect implies a paradigm shift in modern radiotherapy. This research not only responds to a scientific need, but also to a clinical imperative: to offer safer treatments without compromising oncological effectiveness,” says Professor Javier Burguete, professor of Medical and Biophysical Physics at the University of Navarra and director of the thesis.

Personalized medicine

For the University of Navarra, in an international context in which precision medicine and the protection of the immune system occupy a central place in the scientific agenda, this research proposes a technological innovation applied to health with real impact on the quality of life of patients.

In addition, he considers that this advance raises new questions about how to optimize radiotherapy and its effect on the immune system, Adjust the duration of the sessions or redesign the direction of the radiation beams to minimize the blood exposure.

The investigation has had the support of the Spanish Agency for Research -dependent on the Ministry of Science and Innovation -, of the Government of Navarra, the Foundation La Caixa, and the Association of Friends of the University of Navarra, among other institutions.

Its results, says Burguete, “show that protecting blood can be important and influence how a patient evolves after the treatment of a tumor.” As these findings are incorporated into clinical practice, they could mark a before and after in therapeutic planning and the management of side effects in radiotherapeutic oncology.