Value of (18)F-FDG heterogeneity for discerning metastatic from benign lymph nodes in nasopharyngeal carcinoma patients with suspected recurrence.

OBJECTIVE: This study investigated the value of fluorine-18 fludeoxyglucose ((18)F-FDG) heterogeneity as an indicator of metastatic lymph nodes (LNs) in patients with nasopharyngeal carcinoma (NPC). We further assessed whether addition of this parameter improves diagnostic performance beyond that provided by maximum standardized uptake value (SUV(max)). METHODS: We analyzed 74 LNs that were suspicious for metastasis. These LNs were measured for coefficient of variation (CV) of (18)F-FDG uptake, which was used as a parameter for (18)F-FDG heterogeneity. RESULTS: Multivariate logistic regression analyses revealed that a high CV (hazard ratio, 20.97; 95% confidence interval, 2.26-194.62; p = 0.007) was an independent predictor of metastatic LNs. However, receiver-operating characteristic curve analysis (p = 0.278) and net reclassification (p = 0.539) were unable to show improved diagnostic performance by addition of CV to SUV(max). CONCLUSION: High CV of (18)F-FDG uptake is an independent risk factor for metastatic LNs in patients with NPC displaying suspicious LNs following treatment. Advances in knowledge: Heterogeneity of (18)F-FDG uptake has a potential as a biomarker of metastatic LNs.