Prognostic significance of standardized uptake value on 18fluorine-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 ( 18 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 18 F-FDG PET/CT were included in this study. After 18 F-FDG PET/CT, all the patients received radiation therapy and 32 of them received concomitant weekly chemotherapy. The maximum SUV (SUV max ) at the primary tumor and the SUV max of the highest neck nodes were determined. The SUV max -T ranged from 5.00 to 30.80 (mean: 15.37 ± 6.10) and there was no difference between SUV max -T values for early and late stages ( P = 0.99). The SUV max -N ranged from 3.10 to 23.80 (mean: 13.23 ± 5.76). There was no correlation between SUV max -T and SUV max -N ( r = 0.111, P = 0.532). There was no difference between the SUV max -T and the positivity of neck lymph nodes ( P = 0.169). The ability of SUV maks -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 max -N and stage. While the mean SUV max -T for the alive patients was slightly lower than that for the dead (14.65 ± 5.58 vs. 20.30 ± 7.92, P = 0.061), the difference between the groups was not statistically significant. Furthermore, there was no statistically significant difference for SUV max -N between these two groups ( P : 0.494). Cox-regression analysis showed that an increase in SUV max -T and SUV max -N was associated with death risk (relative risk [RR]: 1.13, P = 0.078 and RR: 1.052, P = 0.456, respectively). SUV max -T and SUV max -N were independent prognostic factors for survival in NPC patients. This will help the clinicians in choosing suitable candidates for more aggressive treatment modalities.