Thesis defense of Henning Manke

Intraocular tumours are a life-threatening risk. Smaller tumours can be treated with 106Ru applicators. Meanwhile, more prominent tumours get treated with 125I applicators, which results in a higher risk of side effects, or proton therapy, which is only available at a limited number of specialised centres and may lead to toxic tumour syndrome. Therefore, a novel combined therapy concept is presented and analysed in this thesis. The idea combines using 106Ru applicators and external beam radiotherapy performed with soft X-rays. With the confocal irradiation technique and the utilisation of the 106Ru applicator as a beam-stop for the X-ray beams, healthy tissue is spared from high dosages to reduce the risk of side effects. The combined therapy concept can be implemented in hospitals with relatively low costs and resembles a novel bulb-preserving modality for large intraocular tumours.
As the first steps to this therapy concept, measurements are performed with a novel solid phantom with three different detector types to assess the absorption of the X-rays in the 106Ru applicator. Additionally, the clinical benefit is investigated with a novel software workflow, in which 3D models are created using patient data from the University Hospital Essen in Germany. The modalities are simulated with these 3D models. Dose-volume histograms are presented to evaluate the combined therapy concept and to compare it to stand-alone brachytherapy.