Prognostic Value of Volume-Based 18F-Fluorodeoxyglucose PET/CT Parameters in Patients with Clinically Node-Negative Oral Tongue Squamous Cell Carcinoma

To evaluate the prognostic value of volume-based metabolic parameters measured with 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) in patients with clinically node-negative (cN0) oral tongue squamous cell carcinoma (OTSCC) as compared with other prognostic factors. In this study, we included a total of 57 patients who had been diagnosed with cN0 tongue cancer by radiologic, (18F-FDG PET/CT, and physical examinations. The maximum standardized uptake value (SUVmax), average SUV (SUVavg), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) for primary tumors were measured with (18F-FDG PET. The prognostic significances of these parameters and other clinical variables were assessed by Cox proportional hazards regression analysis. In the univariate analysis, pathological node (pN) stage, American Joint Committee on Cancer (AJCC) stage, SUVmax, SUVavg, MTV, and TLG were significant predictors for survival. On a multivariate analysis, pN stage (hazard ratio = 10.555, p = 0.049), AJCC stage (hazard ratio = 13.220, p = 0.045), and MTV (hazard ratio = 2.698, p 0.033) were significant prognostic factors in cN0 OTSCC patients. The patients with MTV ≥ 7.78 cm3 showed a worse prognosis than those with MTV < 7.78 cm3 (p = 0.037). The MTV of primary tumor as a volumetric parameter of (18F-FDG PET, in addition to pN stage and AJCC stage, is an independent prognostic factor for survival in cN0 OTSCC.