The most commonly quoted advantage of proton therapy over photon therapy is the potential of reducing the deterministic toxicity in normal tissue and the organs at risk (OARs). This is based on the fact that proton treatment optimisation succeeds at producing plans that are ensuring good coverage of the target and steep gradients of the dose outside the target leading thus to a better sparring of the normal tissue and the organs at risk and therefore lower deterministic toxicity. The optimisation of the plans is currently performed assuming a relative biological effectiveness (RBE) of the protons of 1.1 as recommended by the International Committee for Radiation Units. The current 1.1 RBE paradigm, however, has started to be questioned as clinical evidence is gathering pointing towards cases of radiation induced toxicity in the normal tissue that cannot be directly attributed to uncertainties in patient set-up or proton range. A serious radiation protection concern is therefore rising with respect to the use of proton radiation therapy.

Furthermore, the potential risk of second malignant neoplasm induction is also posing a radiation protection dilemma in case of proton therapy.

This project aims therefore at investigating and developing proton treatment planning optimisation approaches that would reduce both the deterministic toxicity and the stochastic effects for the same quality of the plan with respect to the target coverage minimising therefore the radiation protection concerns regarding proton therapy.

The present research project has a high relevance for the radioprotection of patients undergoing proton therapy as it aims at treatment planning optimisation having as objectives the minimisation of the normal tissue toxicity and the reduction of the risk of developing a second tumour induced by the initial treatment. This is of crucial importance since the main group of patients treated at Skandion are relatively young, with a median age below 44 years and with high expectations in terms of curability. Minimising thereby the deterministic effects in the healthy tissue and preventing the stochastic effects would contribute to increasing the benefit of the treatment by increasing the overall quality of life of the patients treated with proton therapy.


For more information contact Iuliana Toma-Dasu