[Individualised radiotherapy on the basis of functional imaging with FMISO PET]

A dose painting strategy in order to overcome hypoxia-induced radiation resistance is presented. 15 HNC patients were examined with 18F-FDG and dynamic 18F-FMISO PET before the start of a 70Gy radiotherapy. After approx. 20 Gy, a second dynamic 18F-FMISO scan was performed The voxelbased 18F-FMISO PET data were analysed with a kinetic model, which allows for the determination of local tumour parameters for hypoxia and tissue perfusion. A statistical analysis showed, that only a combination of these two parameters predicted treatment outcome. A translation of the imaging data into a reliable dose prescription can only be reached via a TCP model that includes these functional parameters. The developed model was calibrated using the outcome data of the 15 HNC patients. This model allows to determine a map of locally varying dose escalation factors to be used for radiotherapy planning. A planning study showed that hypoxia dose painting is feasible without a higher burden for the organs at risk.