Predictive value of metabolic tumor volume measured by 18F-FDG PET for regional lymph node status in patients with esophageal cancer.

OBJECTIVE: The aim of the current study was to investigate the predictive value of metabolic tumor volume (MTV) measured by (18)F-FDG PET/CT for regional lymph node (rLN) metastasis in patients with esophageal cancer.

METHODS: A retrospective review identified 54 patients with surgically resected esophageal cancer who received (18)F-FDG PET/CT at diagnosis of cancer. The (18)F-FDG PET/CT findings for all primary cancer and rLN involvement were compared with the pathologic diagnosis within 5 weeks after surgical resection. The pathologic diagnoses of rLN state were confirmed by surgical resection. Univariate and multivariate analyses were used to analyze the associations among the pathologic rLN status and age, sex, T stage, location, differentiation, maximum standardized uptake value (SUV(max)), MTV2.5, and MTV3.

RESULTS: The rLN(+) group showed statistically significant higher value of SUVmax than the rLN(-) group (P = 0.0011). The rLN(+) group showed statistically significant higher value of MTV2.5 (P = 0.0004) and MTV3 (P = 0.0005) than the rLN(-) group. In receiver operating characteristic analysis, the SUV(max), MTV2.5, and MTV3 did not show the statistical differences for the prediction of pathologic rLN involvement in esophageal cancer. In univariate analysis, T stage, SUV(max), MTV2.5, and MTV3 were factors significantly associated with pathologic rLN involvement. However, in multivariate analysis, the MTV2.5 and MTV3 were factors significantly associated with pathologic rLN involvement in esophageal cancer.

CONCLUSION: Based on the presented results, the MTV measured by (18)F- FDG PET/CT is a useful method for the prediction of pathologic rLN status in esophageal cancer patients. Further studies are needed to confirm these results and improve statistical accuracy.