Tumour volume of resectable oesophageal squamous cell carcinoma measured with MRI correlates well with T category and lymphatic metastasis.

Objectives: To determine association of gross tumour volume (GTV) of resectable oesophageal squamous cell carcinoma (SCC) measured on T-weighted imaging (TWI), contrast-enhanced T-weighted imaging (CE-TWI) and diffusion-weighted imaging (DWI) with T category and lymphatic metastasis (LM).

Methods: Sixty oesophageal SCC patients underwent fat-suppressed TWI, CE-TWI and DWI with b values of 0, 500 and 800 s/mm. GTV was measured on three sequences. Statistical analyses were performed to determine association of GTV with T category and LM.

Results: Spearman's rank correlation analysis showed positive association of GTV with T category and LM (all p values < 0.01). Differences in GTV were found between T1 and T2 or T3 categories shown by Kruskal-Wallis H and one-way ANOVA tests, and between T1/T2 and T3 and between tumours with and without LM by Mann-Whitney U tests (all p values < 0.05). Receiver operating characteristic analyses showed cut-off GTVs of 5.795, 5.276 and 10.11 cm on CE-TWI could better differentiate T1 from T2 categories, T1 from T3, and T1-2 from T3 than those of 7.066, 7.045 and 8.504 cm on TWI, of 5.793, 6.609 and 6.989 cm on DWI with b value of 500 s/mm, and of 4.156, 4.519 and 4.985 cm with b value of 800 s/mm, respectively. Cut-off of 10.462 cm on DWI with b value of 500 s/mm could better identify LM than of 12.38, 8.793 and 9.600 cm on TWI, CE-TWI and DWI with b value of 800 s/mm, respectively.

Conclusions: GTVs on TWI, CE-TWI and DWI are associated with T category of and LM of oesophageal SCC.

Key Points: • GTV is associated with T category and lymphatic metastasis of oesophageal SCC • GTV measured on contrast-enhanced T -weighted imaging better identifies T category • GTV measured on DWI with b value of 500 s/mm better identifies lymphatic metastasis.