The maximum standardized uptake value increment calculated by dual-time-point 18F-fluorodeoxyglucose positron emission tomography predicts survival in patients with oral tongue squamous cell carcinoma.

The aim of this study was to investigate the prognostic value of dual-time-point (DTP) 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) imaging in primary oral tongue squamous cell carcinoma (OTSCC). The study included 52 patients who underwent preoperative 18F-FDG PET scans at two time points, namely 1 h and 2 h after injection. The following PET parameters were calculated: maximum standardized uptake value (SUVmax) for both time points (SUV early, SUV delayed); retention index (RI); and SUVmax increment (ΔSUVmax). Receiver operating characteristic (ROC) curve analysis was performed to define the optimal cutoff point for these parameters. Overall survival was calculated using the Kaplan-Meier method. Prognostic factors for patients with OTSCC were evaluated using the univariate log-rank test and a multivariate Cox proportional hazards model. ROC analysis revealed that the area under the curve was higher and more accurate for ΔSUVmax than for the other parameters. Additionally, patients with a ΔSUVmax ≥0.9 had significantly worse survival outcomes (28.9% vs 92.6%; p < 0.01). Univariate analysis showed that prognosis was significantly correlated with clinical T stage, local recurrence, perineural invasion, vascular invasion, and PET parameters (p < 0.05 for all). Multivariate analysis showed that local recurrence (hazard ratio = 3.60; p = 0.02) and ΔSUVmax (hazard ratio = 8.43; p < 0.01) were independent prognostic factors. ΔSUVmax determined using DTP 18F-FDG PET may be an additional prognostic factor in OTSCC patients.