On-Site PhD conferral mrs. Petronella (Patricia) J.A.M. Brouwers

Key words: late side effects, cosmetic, cardiac damage, registering toxicity

"Towards understanding and reducing late side effects of radiotherapy"

The goal of this dissertation was to gain insight in the different aspects of several late side effects in breast cancer patients who had breast-saving treatment. It appears that a higher dose of radiation (a photon boost instead of an electron boost), a larger radiation area and supplementary chemotherapies are risk factors for a cosmetically less attractive breast. Additionally, we found that our Voluntary moderately Deep Inspiration Breath Hold technique (patient holds their breath during radiation) is a simple and valuable way to reduce the radiated heart volume and therefore later-occurring cardiac damage. Lastly, we demonstrated the structural registration of late side effects through patient questionnaires ensures patients who need extra care are identified. Structural registration also makes the development of prognostic models possible as well as outcome data comparison among centres.