Objectives: To investigate the role of PET-derived imaging markers in predicting metastatic nasopharyngeal carcinoma (NPC) outcomes.
Materials and methods: A total of 56 patients with metastatic NPC were enrolled. Before treatment, all of the participants underwent (18)F-FDG PET/CT. The following (18)F-FDG PET parameters were assessed: standardised uptake value, metabolic tumour volume (MTV), and total lesion glycolysis. Multivariate Cox proportional hazards models were used to identify the independent predictors of survival.
Results: The multivariate analysis showed that performance status>1 (P=0.007), Epstein-Barr virus (EBV) DNA titre>5000 copies/mL (P=0.001), and MTV>110 mL (P=0.013) were independent risk factors for progression-free survival (PFS). Male sex (P=0.004), performance status>1 (P<0.0001), EBV DNA level>5000 copies/mL (P<0.0001), and MTV>110 mL (P=0.003) independently predicted overall survival (OS). The 2-year PFS and OS rates of the patients with MTV≤110 mL were 23.2% and 43%, respectively, compared with 0% and 9.1%, respectively, for those with MTV>110 mL. Combining the MTV with the EBV DNA titre allowed further survival stratification by dividing the patients into three groups with distinct PFS (2-year rates=30.8%, 7.1%, and 0%, P<0.0001) and OS (2-year rates=68.4%, 40%, and 0%, P<0.0001) rates.
Conclusion: The MTV appears to be an independent risk factor in metastatic NPC patients. This factor is complementary to the EBV DNA titre for predicting survival in metastatic NPC.
Copyright © 2012 Elsevier Ltd. All rights reserved.