Prognostic Value of FDG PET/CT-Derived Metabolic Parameters in Non-Metastatic Nasopharyngeal Carcinoma

This study aimed to evaluate the prognostic significance of metabolic parameters, including maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG), of both the primary tumor and the largest lymph node before treatment in patients with locally advanced nasopharyngeal carcinoma (NPC). A total of 68 patients diagnosed with NPC who underwent pre-treatment 18F-FDG PET/CT were retrospectively analyzed. Patient characteristics, including age, gender, T stage, and N stage, as well as PET-derived parameters (SUVmax, SUVmean, and SUVpeak of the primary tumor, MTV, TLG, and SUVmax of the largest lymph node) were assessed. Following treatment, patients were monitored for up to 159 months (median follow-up: 75 months) to evaluate disease progression and survival outcomes. Kaplan–Meier survival analysis was performed to assess the impact of PET parameters on progression-free survival (PFS) and overall survival (OS). Univariate analysis revealed a significant association between T-SUVmax (p = 0.040), T-SUVpeak (p = 0.013), TLG (p = 0.037), and LN-SUVmax (p = 0.011) with OS. Additionally, the chi-square test showed that T stage (p = 0.036), N stage (p = 0.004), and M stage (p = 0.004) were significantly associated with OS. A statistically significant correlation was observed between lymph node SUV values and both PFS (p = 0.033) and OS (p = 0.029). However, tumor SUV values were not significantly correlated with PFS (p = 0.567) or OS (p = 0.862). In multivariate analysis, lymph node SUVmax emerged as an independent prognostic factor (p = 0.002). Kaplan–Meier survival curves demonstrated a progressive decline in PFS and OS as lymph node stage advanced from N1 to N3. Furthermore, a statistically significant association was found between lymph node metastasis at diagnosis (chi-square test, p = 0.05), lymph node SUVmax (p = 0.034), and tumor TLG (p = 0.025) with disease progression during follow-up. Pre-treatment PET/CT-derived metabolic parameters, particularly lymph node SUVmax and tumor TLG, along with anatomical N stage, serve as significant prognostic factors for long-term PFS in non-metastatic nasopharyngeal carcinoma. These findings highlight the potential role of PET/CT in refining risk stratification and guiding personalized treatment strategies in NPC. Median survival time: 95% Confidence Interval (45.973–130.027 months).