Metabolic features predicting distant metastasis in patients with nasopharyngeal carcinoma

Objectives: Patients with nasopharyngeal carcinoma may suffer distant disease dissemination. However, a reliable prognostic indicator for occurrence of distant metastasis has not been explored thoroughly. We evaluated whether the metabolic features on ¹⁸F-FDG PET/CT can predict distant metastasis in patients with nasopharyngeal carcinoma.

Methods: We retrospectively reviewed consecutive 71 patients, who were diagnosed with stage III, IVA, and IVB nasopharyngeal carcinoma in Severance Hospital from 2006 to 2015, and underwent ¹⁸F-FDG PET/CT before any treatment. The maximum standardized uptake values (SUV) for primary site, and lymph node with highest uptake were measured in each patient. All values were corrected for uptake in the liver.

Results: Patients were followed up for 36.0 ± 40.9 (3.8 to 112.4) months. All patients received concurrent chemoradiation therapy with or without consolidation chemotherapy. Of 71 patients, distant metastasis was developed in 14 (19.7%) patients. Cox proportional-hazards regression identified that a higher maximum SUV of metastatic lymph node predicted development of distant metastasis (P = 0.046). The maximum SUV of primary site (P = 0.49) did not predict distant disease dissemination.

Conclusion: We identified that higher maximum SUV of metastatic lymph node was associated with an increased risk of distant dissemination in patients with nasopharyngeal carcinoma. Further validation in a larger number of patients is warranted. Research Support: None