PhD defence M. (Marloes) Duijm

This research is focusing on non-metastatic lung tumors which are located within 2 cm of the critical organs such as the trachea and esophagus. Patients who do not quality for surgery, can be treated with stereotactic radiotherapy. This stereotactic technique guaranties high precision radiotherapy.

After analyzing this patient group within several institutes we were able to show the survival, disease control and side-effects of this treatment. First, we developed a model to predict the overall survival of these patients based on age, performance status, location of the tumor, treated volume and the dose to the treated volume. Additionally, having a bigger tumor volume, a lower forced expiratory volume within one second and/or a tumor in one of the lower lobes was associated with disease recurrence.

The second part of this thesis is describing the relation between the prescribed dose to the organs at risk and the toxicity probabilities. In case of the bronchial structures, the radiological chances after the stereotactic treatment and the relation with the prescribed dose has been described. Moreover, the relation between dose and the side effects of both the bronchial structures and the esophagus has been analyzed. After identifying these predictive dosimetric parameters, Normal Tissue Complication Probability models were plotted for each dosimetric parameter. These models can show the toxicity probability at the various dose points and could guide physicians in future treatment planning.

Due to corona, the PhD defences do not take place publicly in the usual way in the Senate Hall or in the Professor Andries Querido Room. The candidates will defend their dissertation either in a small group or online