Prognostic Significance of Standardized Uptake Value on 18 Fluorine-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Patients with Nasopharyngeal Carcinoma

The aim of this study was to investigate the prognostic significance of standardized uptake value (SUV) on 18 fluorine-fluorodeoxyglucose ( F-FDG) positron emission tomography/computed tomography (PET/CT) in patients with nasopharyngeal carcinoma (NPC). Thirty-four patients who have histologically proven NPC and underwent F-FDG PET/CT were included in this study. After F-FDG PET/CT, all the patients received radiation therapy and 32 of them received concomitant weekly chemotherapy. The maximum SUV (SUV ) at the primary tumor and the SUV of the highest neck nodes were determined. The SUV -T ranged from 5.00 to 30.80 (mean: 15.37 ± 6.10) and there was no difference between SUV -T values for early and late stages ( = 0.99). The SUV -N ranged from 3.10 to 23.80 (mean: 13.23 ± 5.76). There was no correlation between SUV -T and SUV -N ( = 0.111, = 0.532). There was no difference between the SUV -T and the positivity of neck lymph nodes ( = 0.169). The ability of SUV -N to predict stage was obtained by a receiver operating characteristic (ROC) analysis. The area under the curve is 0.856 and the best cut-off value is 7.88. There was a good correlation between SUV -N and stage. While the mean SUV -T for the alive patients was slightly lower than that for the dead (14.65 ± 5.58 vs. 20.30 ± 7.92, = 0.061), the difference between the groups was not statistically significant. Furthermore, there was no statistically significant difference for SUV -N between these two groups (P: 0.494). Cox-regression analysis showed that an increase in SUV -T and SUV -N was associated with death risk (relative risk [RR]: 1.13, = 0.078 and RR: 1.052, = 0.456, respectively). SUV -T and SUV -N were independent prognostic factors for survival in NPC patients. This will help the clinicians in choosing suitable candidates for more aggressive treatment modalities.