Tumour size of resectable oesophageal squamous cell carcinoma measured with multidetector computed tomography for predicting regional lymph node metastasis and N stage

Objectives To determine whether and how tumour size of resectable oesophageal squamous cell carcinoma (ESCC) measured with multidetector CT could predict regional lymph node metastasis (LNM) and N stage. Methods Two hundred five patients with ESCC underwent radical oesophagectomy with three-field lymphadenectomy less than 3 weeks after contrast-enhanced CT. Tumour size of the ESCC (tumour length, maximal thickness and gross tumour volume, GTV) was measured on CT. Statistical analyses were performed to identify whether tumour size could predict regional LNM and N stage, and to determine how to use the size of ESCC to predict N stage. Results Univariate analysis showed that tumour size could predict regional LNM (all P < 0.05). Logistic regression analysis revealed that GTV could independently predict regional LNM ( P = 0.021, odds ratio = 1.813). Mann-Whitney tests showed that tumour size could distinguish grouped N stages (all P < 0.05). GTV might be a differentiating indicator between N0 and N1–3 stages (cutoff, 14.4 cm 3 ), between N0–1 and N2–3 (cutoff, 15.9 cm 3 ), and between N0–2 and N3 (cutoff, 26.1 cm 3 ), with sensitivity of 76%, 63% or 75%, and specificity of 75%, 61% and 81%, respectively. Conclusions The GTV of ESCC measured with CT could be an indicator for predicting regional LNM and grouped N stages. Key Points • Multidetector computed tomography (MDCT) allows accurate assessment of oesophageal tumour size • For resectable squamous cell tumours, size helped predict regional lymph node involvement • Gross tumour volume may predict the N stage of oesophageal squamous cell carcinoma