Diamond detector based microdosimetry: key solution in the determination of the radiobiological effectiveness? (R-9972)

This research project is situated within the context of radiotherapy in which ionizing radiation is used to destroy tumors, and focuses more specifically on hadron therapy. The radiation bundle consists of protons or heavy ions. Five new Hadron Therapy Centres are currently being planned or under construction in Belgium and the Netherlands. The medical radiation physicists already have a wide range of measuring equipment at their disposal to measure very accurately the amount of radiation administered to the patient. The radiation dose is used in Gray (Gy). In this project, we want to shift our focus from that dose to another aspect of ionising radiation, namely radiation quality. The radiation quality parameter concerns the estimation of the damage caused by radiation when crossing living tissues. It has been demonstrated for years that different types of radiation (different energies and/or different particles) are not the same in this regard. For instance, a dose of 1 Gy neutrons causes as much damage in living tissues as a dose of 20Gy photons with an energy of 6MV. However, this radiation quality is simply not measurable in clinical conditions. Experiments, for example, can be carried out using cell cultures or live animals to evaluate radiobiological effectiveness (RBE), but the wide range of materials required for these measurements make frequent use in a (busy) hospital impossible. We therefore want to develop a method in this project that is based on the use of a physical dosimeter, a microdosimeter, that can be routinely used in a clinical environment. Hereby, the result of the physical measurements is related to the relative biological effectiveness (RBE) for a specific biological endpoint. In this way, the use of this microdosimeter can be applied to determine the radiation quality in clinical circumstances.

Keywords:development of nuclear measuring equipmen, radiological contaminations

Disciplines:Radiation therapy