Determination of regional lymph node status using18F-FDG PET/CT parameters in oesophageal cancer patients: comparison of SUV, volumetric parameters and intratumoral heterogeneity

We aimed to investigate whether the standardized uptake values, volumetric parameters and intratumoral heterogeneity of fluorine-18-fludeoxyglucose ((18)F-FDG) uptake could predict regional lymph node (rLN) metastasis in oesophageal cancer.51 patients with surgically resected oesophageal cancer were included in the present study. The (18)F-FDG positron emission tomography (PET)/CT findings and rLN metastasis were compared with the histopathological results. The intratumoral metabolic heterogeneity was represented by the heterogeneity factor (HF), which was determined for each patient. Univariate and multivariate analyses were used to analyse the associations between the rLN metastasis and clinical findings, standardized uptake values, metabolic tumour volume (MTV), total lesion glycolysis (TLG) and HF.The rLN(+) group showed statistically significant higher values of MTV (median, 13.59 vs 6.6; p = 0.0085), TLG (median, 119.18 vs 35.96; p = 0.0072) and HF (median, 3.07 vs 2.384; p = 0.0002) than the rLN(-) group. Univariate analysis showed that maximum standardized uptake value, mean standardized uptake value, MTV, TLG and HF were significantly associated with pathologic rLN involvement. However, in multivariate analysis, the HF was a potent associated factor for the prediction of pathologic rLN metastasis in oesophageal cancer.In conclusion, (18)F-FDG PET/CT parameters such as maximum standardized uptake value, mean standardized uptake value, MTV, TLG and HF were useful for the prediction of pathologic rLN status in patients with oesophageal cancer. However, HF might be the most powerful predictor of rLN metastasis of patients with oesophageal cancer.Assessment of intratumoral heterogeneity of (18)F-FDG PET/CT may be a useful adjunct for rLN staging of oesophageal cancer.