Abstract
PURPOSE: Oral cavity squamous cell carcinoma (OCC) can spread to the neck without apparent lymphadenopathy. Pretreatment detection or prediction of occult metastasis might contribute to proper management of clinically node-negative (cN0) OCC. We examined the role of tumour quantitative 18-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET)/computed tomography (CT) measurements for predicting OCC occult metastasis and survival. METHODS: This study included 130 cN0 OCC patients who underwent (18)F-FDG PET/CT scanning and subsequent curative surgery and neck dissection. Maximum, peak, and mean standardized uptake value (SUV(max), SUV(peak), and SUV(mean)), metabolic tumour volume (MTV), and total lesion glycolysis (TLG) were measured on pretreatment (18)F-FDG PET/CT. Binary logistic regression was used to identify factors predicting occult cervical metastasis. Univariate and multivariate Cox proportional hazard regression were used to find factors associated with overall survival (OS). RESULTS: Pathological cervical metastasis (pN +) was found in 29 (22.3%) patients. Age, tumour differentiation, lymphovascular invasion, and T classification were significantly associated with pN + (all P < 0.05). After adjustment for these factors, MTV and TLG independently predicted pN + (P < 0.05). Invasion depth, lymphovascular invasion, T and N classifications, and overall TNM stage were significantly associated with OS. After adjustment for these factors, SUV(max) and TLG independently predicted OS (all P < 0.05). Patients with TLG > 9.3 g had a 5.7-fold increased risk of overall mortality. CONCLUSIONS: Tumour (18)F-FDG PET/CT parameters might predict occult metastasis and survival in cN0 OCC patients.