Comparison between CT- and FDG-PET-defined target volumes for radiotherapy planning in head-and-neck cancers

Nine patients with head-and-neck cancer underwent computerized tomography (CT) simulation and [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET) to compare the radiotherapy target volumes. The PET volumes were delineated with an automatic segmentation based on the source-to-background ratio. The volume comparison showed a reduction and qualitative discrepancies between the PET- and CT-volumes.