All were planned to be subjected to whole body18F FDG-PETimaging in order to evaluate suspected either loco-regionalrecurrence or distant metastasis. Because the PET system wasdismantled and replaced by a new PET/CT device, only 32patients were imaged by the PET system while the rest of thepaents (35) were imaged by the PET/CT system and for thesame purposes. All imaging results will be compared to theresults of contrast-enhanced CT.