Performance of 18F-FDG PET/contrast-enhanced CT in the staging of squamous cell carcinoma of the oral cavity and oropharynx

The aim of this study was to assess the diagnostic value of integrated whole body positron emission tomography/contrast-enhanced CT (PET/CECT) as a one step examination in the initial staging of oral and oropharyngeal squamous cell carcinoma (OOSCC). Seventy three consecutive OOSCC patients who underwent PET/CECT for initial staging and tumour resection and neck dissection as primary treatment, were included. For each PET/CECT result, the contribution of fluorine-18 fluorodeoxyglucose ((18)F-FDG)-uptake and radiologic criteria was assessed. PET/CECT results were correlated to histological specimens obtained with tumour resection and neck dissection. For detecting the primary tumour PET/CECT showed a sensitivity of 96% and for detecting cervical metastases a sensitivity and specificity of 89% and 81%, respectively. In the clinically N0 subgroup (n=37), PET/CECT showed a sensitivity and specificity of 64% and 81%, respectively. In five of six patients PET/CECT detected a second primary tumour. The results show that the use of diagnostic PET/CECT as a one step examination is a reliable alternative for PET/CT in combination with a separate diagnostic CT in patients with OOSC for initial staging. The need for treatment of the neck in the clinically negative neck should not be based on PET/CECT results only, due to the risk of missing a small metastasis.