Session Speaker

Advanced MRI imaging in delineation of target volume for radiotherapy of differentiated gliomas
Rafal Tarnawski, Barbara Billewicz-Bobek, Adam Idasiak
Poland

Modern radiotherapy techniques have theoretical precision in range of 1 mm. Intensity Modulated Radiotherapy (IMRT) together with Image Guided Radiotherapy (IGRT) are commonly used for treatment of brain tumors. Delineation of tumor borders is difficult in case of gliomas even with the use of CT/MRI fusion. Advanced MRI techniques together with PET (Positron Emission Tomography) using specific tracers, have to be applied in order to visualize tumor/tumor borders. The most robust MRI techniques are PWI and DTI. 3D Magnetic Resonance Spectroscopy is very promising tool that may be applied to RT planning. Regions of increased signals of lactic acid may be related to hypoxia, the most probable reason of gliomas radioresistance. Increased signals of choline may be related to regions of increased proliferation. It is not clear, how to include metabolic information in treatment of glioma patients. The possibilities are: to increase radiation dose in regions of altered metabolic activity, the use of new drugs, antiangiogenic agents, hypoxia modifiers.

Novel trials may address these questions but advanced imaging have to be used during these studies in order to join the treatment individualization of novel drug treatment with potential and precision of modern radiotherapy techniques.