These results will help to better predict the risk of developing secondary cancers after radiotherapy 

Predicting a patient’s risk of developing a secondary cancer as a result of the radiation received during radiotherapy is not easy. One of the reasons for this is the limited ability to estimate the small doses of radiation absorbed by organs that are far from the treated area. This is where Lorenzo Brualla, leader of the HARMONIC task dedicated to dose reconstruction in paediatric cancer patients, and his colleagues come in.

“In order to compute this small dose, it is necessary to have a precise knowledge of the geometrical description of the irradiating device, but this information is usually not provided by the manufacturers due to trade secrets,” explains Brualla, professor at the University of Medicine Essen and the West German Proton Therapy Centre.

In this study, he and colleagues in Panama and Spain provide a solution to circumvent this problem for a medical linear accelerator commonly used in modern radiotherapy. The researchers used the geometry information from another model. The results obtained show that this approach works well if certain adjustments are made to the simulation parameters.

For Brualla, this solution “contributes to the efforts made within HARMONIC to systematically calculate the whole-body radiation dose to the patient.” The authors also point out that the proposed approach helps in the verification process of radiotherapy treatments planned with this linear accelerator.

The overall goal of HARMONIC is to better understand – and mitigate – the long-term health effects of medical exposure to ionising radiation in children, including secondary cancers in patients treated with modern radiotherapy techniques.



Rodriguez M, Sempau J and Brualla L. Monte Carlo simulation of the Varian TrueBeam flattened‑filtered beams using a surrogate geometry in PRIMO. Radiation Oncology. 2024. Doi: 10.1186/s13014-024-02405-w