Block copolymer micelles have been used to encapsulate various chemotherapeutic drugs, which can be delivered to the tumour site using the so-called Enhanced Permeation and Retention effect. However, these micelles usually release the encapsulated drugs in uncontrolled manner. There are various ways to trigger drug release by external and internal stimuli, one of which is ionizing radiation. The use of ionizing radiation as a trigger is only of interest if release can be achieved at a low radiation dose, i.e. in the order of a dose received in a diagnostic scan. For this purpose we have investigated different block copolymer systems, which can respond to radiation. In this study we want to determine any changes occuring in the self-assemblies when irradiated which lead to the osberved release.