Signal enhancement ratio of CE-MRI: a potential biomarker of survival after hepatic arterial infusion chemotherapy in biliary tract cancers

Background The association of contrast-enhanced MRI (CE-MRI) and the overall survival (OS) of biliary tract cancers (BTC) is ambiguous. Thus, the aim of this study is to evaluate the value of signal enhancement ratio (SER) and its early change in CE-MRI as biomarkers of survival after hepatic arterial infusion chemotherapy (HAIC) in BTC. Results One hundred and two BTC patients treated via HAIC with 3cir-OFF regimen between January 2011 and June 2020 were enrolled in this retrospective study. The median progression-free survival (PFS) and OS were 9.8 months [range 1.5–83.3 months, 95% confidence interval (CI) 7.789–11.811] and 14.2 months (range 1.8–83.3 months, 95% CI: 11.106–17.294), respectively. The cutoff value of SER before HAIC (SER 0 ) was 1.04, and both median PFS and OS in the SER 0 ≥ 1.04 group were longer than in the SER 0 < 1.04 group (median PFS: 10.5 vs. 8.5 months, p = 0.027; median OS: 23.9 vs. 12.3 months, p < 0.001). The median OS in the ΔSER > 0 group was longer than in the ΔSER < 0 group (17.3 versus 12.8 months, p = 0.029 (ΔSER means the change of SER after two cycles of HAIC). Multivariate analysis showed SER 0 ( p = 0.029) and HAIC treatment cycle ( p = 0.002) were independent predictors of longer survival. Conclusions SER in CE-MRI before HAIC (SER 0 ) is a potential biomarker for the prediction of survival after HAIC in advanced BTC.