Value of [18F]FDG PET-CT in the follow-up of surgically treated oral tongue squamous cell carcinoma: single centre cohort analysis on 87 patients

Background: To evaluate the diagnostic performance of [F-18]fluorodeoxyglucose positron emission tomography/computed tomography ([F-18]FDG-PET/CT) scan in detecting local recurrences in patients with surgically treated oral tongue squamous cell cancer (OTSCC).Material and methods: Eighty-seven patients who had undergone surgery for OTSCC were monitored clinically and [F-18]FDG PET/CT and magnetic resonance (MR). PET uptakes were classified as functional (Type A), suspicious (Type B), or highly suggestive of local recurrence (Type C). A multidisciplinary team (MDT) evaluated case-by-case the surveillance strategy based on PET uptake.Results: Fifty-nine patients presented FDG-PET uptake during follow-up: this report was significantly more frequent in patients who received flap reconstruction than in those without (73% vs 50%; p = 0.05). In 13 patients with Type A (n = 1), Type B (n = 9), and Type C (n = 3) uptakes an additional MR was considered preferable and discovered recurrence in 12.PET-CT had 9 true positives, 17 false positives, 71 true negatives, and no false-negative, resulting in sensitivity, specificity, positive (PPV) and negative predictive values (NPV) of 100%, 80.7%, 34.6%, and 100%.Conclusions: The present results demonstrated a change in diagnostic strategy, as decided by the MDT, in about one-fifth of patients. The results should prompt in designing a rational surveillance schedule in surgically treated OTSCC.