Prediction of Occult Lymph Node Metastasis by Metabolic Parameters in Patients with Clinically N0 Esophageal Squamous Cell Carcinoma

다국어 초록 (Multilingual Abstract)

<P>The aim of this study was to investigate the value of <SUP>18</SUP>F-FDG parameters of the primary tumor in predicting occult lymph node metastasis in patients with clinically N0 esophageal squamous cell carcinoma. <B>Methods:</B> The study comprised 143 consecutive patients (mean age ± SD, 63.9 ± 8.6 y; range, 31.8–81.2 y) from May 2003 to January 2010 who had clinically N0 esophageal squamous cell carcinoma based on preoperative imaging studies including chest CT, <SUP>18</SUP>F-FDG PET/CT, and endoscopic ultrasound. We measured maximum standardized uptake value (SUV<SUB>max</SUB>), mean SUV (SUV<SUB>mean</SUB>), total lesion glycolysis (TLG), and metabolic tumor volume (MTV) of the primary tumor and analyzed the relationship between clinicopathologic variables including PET parameters and occult lymph node metastasis using a logistic regression model. <B>Results:</B> Univariate analysis indicated that clinical T classification, SUV<SUB>max</SUB>, SUV<SUB>mean</SUB>, MTV, TLG, and longitudinal diameter of tumor were significant risk factors associated with occult lymph node metastasis. Optimal thresholds were cT2–4, SUV<SUB>max</SUB> ≥ 4.8, SUV<SUB>mean</SUB> ≥ 3.2, MTV ≥ 5.5 cm<SUP>3</SUP>, TLG ≥ 220, and diameter ≥ 3.8 cm. After multivariate analysis, the logistic regression model revealed that clinical T classification (hazard ratio [HR], 4.6; 95% confidence interval [CI], 1.7–12.4; <I>P</I> = 0.003) and SUV<SUB>max</SUB> (HR, 3.5; 95% CI, 1.3–9.2; <I>P</I> = 0.012) were independent risk factors. The combination of SUV<SUB>max</SUB> and clinical T classification (HR, 13.2; 95% CI, 5.4–31.9; <I>P</I> < 0.001) was a significantly better powerful risk factor for occult lymph node metastasis than SUV<SUB>max</SUB> or clinical T classification alone. Sensitivity, specificity, positive predictive value, and negative predictive value of the combination of clinical T classification and SUV<SUB>max</SUB> were 73.0%, 81.5%, 60.0%, and 89.7%, respectively. <B>Conclusion:</B> SUV<SUB>max</SUB>, combined with clinical T classification, may be useful for predicting occult lymph node metastasis in patients with clinically N0 squamous cell carcinoma of the esophagus.</P>