18F-FDG-PET/CT of orofacial tumors, a value of whole-body imaging approach

AimStaging of head and neck tumors is one of the most difficult tasks in imaging techniques, due to the very complicated head and neck anatomy and serious problems with the differentiation of reactive enlarged lymph nodes and lymph nodes involved with metastases. The aim of the study was to evaluate the validity of the whole-body approach in the assessment of head and neck malignancies using 18F-FDG-PET/CT.Materials and methodsThe analysis of a group of 1750 consecutive whole-body procedures in all indications of 18F-FDG-PET/CT was made according to: the presence of orofacial tumors; their histology; findings concerning the spread outside head and neck region; and findings concerning the primary staging or restaging. The examinations of head and neck tumors were performed after intravenous application of the 18F-FDG and its accumulation for one hour. Drinking and speaking is restricted during this accumulation to prevent artificial muscle 18F-FDG uptake and to minimize false positive findings. In our hospital, high resolution PET is followed by the sub-millimeter isotropic acquisition of CT data after intravenous application of an iodinated contrast material. The acquisitions of head and neck region and trunk are performed separately to obtain optimal resolution in both regions.Results105 examinations of the orofacial tumors were performed on 87 patients in a group of 1750 consecutive PET/CT examinations. The ratio between primary staging and restaging was 3:7. The most frequent indications were carcinomas of the tongue (19 examinations) and carcinomas of the salivary glands (19 examinations). The metastatic spread of the tumor outside the region of the head and neck was noted in 12 cases.ConclusionOur findings of distant metastases confirmed the importance of the use of whole-body PET/CT in this indication.