Evaluation of oral cavity carcinomas by 18FDG PET/CT: Diagnostic pathologic patterns with illustrative case examples

1300 Learning Objectives The aim of this exhibit is: 1. To show the different patterns of normal FDG uptake in the oral cavity, including tongue, floor of the mouth, buccal mucosa, gingiva, alveolar ridge, hard palate, retromolar trigone and anterior tonsillar pillar. 2. To show the different uptake patterns in different locations and types of oral cavity carcinoma at the initial staging, recurrence diagnosis and response to therapy assessment. 18FDG PET/CT has improved the initial staging of oral cavity carcinomas. It is superior to CT and MRI in assessing the nodal status particularly in normal size lymph nodes. Furthermore; it can differentiate between postoperative changes and residual active disease in addition to its inherent superiority in assessing distant sites of metastases in one imaging setting. PET/CT reader should be aware of the most common pitfalls and normal variant that can decrease significantly the false positive rates in PET/CT.