The target of modern radiooncological therapy technics, such as the intensity modulated radiotherapy (IMRT) as well as the image supported radiotherapy (IGRT) is to irridate the tumor as precisely as possible to achieve a good control of the tumor and at the same time to take care of the surrounding normal tissue. Especially in movable tumor regions this target cannot always be realized very easily.
It is not possible to measure continuously the movement of the prostate during radiotherapy taking up to 30 minutes as IGRT with the actually existing systems, and to reposition the organ accordingly. By permitting an electromagnetic positioning of the target volume as well as an online control of the target volume, a solution is provided to address the issues. Three transmitters sized only a few millimetres (on average 8,5 mm) are placed in the prostate analogically to the prostate seed treatment. Through an antenna placed above patient, the position of the transmitters in the room can be registered exactly and divergences concerning the planned therapy can be recorded.