[Significance of PET and integrated PET/CT in the diagnostics of occult primary tumors].

Background: In the last years (18)F-FDG-positron-emission-tomography (PET) worked satisfactorily as helpful auxiliary method in order to verify recurrency of head and neck tumors and to detect primary tumors in case of CUP syndrome especially when CT and MR imaging failed to identify the tumor accurately. Fusion of FDG hypermetabolism in PET scan and anatomical structures is achieved by integrating positron emission tomography with CT and provides improvement also in case of CUP syndrome. This retrospective study shows 47 patients with neck metastases where PET or PET/CT helped to detect primary tumor site.

[The integrated PET/CT: technological advance in diagnostics of head and neck recurrencies and CUP?].

Background: In the last years (18)F-Fluoro-deoxy-glucose (FDG)-positron emission tomography (PET) worked satisfactorily as auxiliary method in order to show recurrency of head and neck tumors and to detect primary tumors in case of CUP especially when CT and MR imaging failed to identify the tumor accurately. The correlation of FDG hypermetabolism and anatomical structures is now provided by a new technology which is integrating PET and CT: Integrated PET/CT represents a new technical development, which combines the advantages of CT and PET.

Patients: In a retrospective investigation 84 non selected PET/CT studies of 83 patients with recurrent head and neck disease and CUP were critically analyzed.