The risk of harboring occult metastasis in levels I, IV, and V when levels II and III are negative is low. Levels II and III neck dissection is likely to be an effective staging procedure in patients with isolated parotid metastases.

Physical activity before F-FDG PET/CT can cause increased muscle glucose metabolism. We report markedly increased glucose metabolism in the masseter and temporalis muscles of a 53-year-old man who was clenching his teeth before the scan, and then resolution of this increased metabolism on a second scan 12 weeks later. SUVmax in the right masseter muscle was 26.9; 12 weeks later, the SUVmax was 1.6. This level of FDG uptake in bruxism has not yet been reported.