[PET scanning in head and neck cancer]

INTRODUCTION: FDG (fluorine-labeled deoxy-glucose) and 11C-methionine positron emission tomography was evaluated in the diagnostics of head and neck cancer. PET scans were applied for identifying/staging relapse after oncotherapy or searching unknown primary tumor with metastatic lymph nodes of the neck. METHODS: Retrospective analysis of 22 patients examined by 17 (18)FDG and 15 (11)C-methionine PET scan. In 9 cases indication was unknown primary tumor with positive neck, in 13 cases previously treated head and neck cancer patients were examined for recurrence/restaging. RESULTS: In searching for unknown primary tumor not detectable with conventional methods, PET was effective in 22%, however, false positivity and uncertain results were found as well. In restaging PET proved to be very effective (85%) to discover recurrences and to differentiate them from post-treatment (mainly irradiation) effects. In two cases silent distant metastase were detected. CONCLUSION: PET can provide valuable information about unknown primary tumors, recurrences after oncotherapy and distant metastases as well. Simultaneous use of FDG/methionine scans does not improve the results.