Transarterial Chemoembolization and Radioembolization for Unresectable Intrahepatic Cholangiocarcinoma-a Systemic Review and Meta-Analysis

Purpose Intrahepatic cholangiocarcinoma (ICC) has a poor prognosis, when unresectable; therefore, intra-arterial therapies (IAT) such as trans-arterial chemoembolization (TACE) and trans-arterial radioembolization (TARE) have been employed. With the present systematic review and meta-analysis, we aimed to analyse published studies to understand if one IAT can be superior to the alternative. Materials and methods A systematic search of PubMed and Web of Science databases was performed for articles published until 1 March 2020 relevant to IAT for ICC. Overall survival was the primary end point. Occurrence of clinical adverse events and tumour overall response were secondary outcome measures. Results A total of 31 articles (of 793, n.1695 patients) were selected for data extraction, 13 were on TACE (906 patients) and 18 were on TARE (789 patients). Clinical and tumour characteristics showed moderate heterogeneity between the two groups. The median survival after TACE was 14.2 months while after TARE was 13.5 months (95%C.I.: 11.4-16.1). The survival difference was small (d = 0.112) at 1 year and negligible at 2 years (d = 0.028) and at 3 years (d = 0.049). The radiological objective response after TACE was 20.6% and after TARE was 19.3% (d = 0.032). Clinical adverse events occurred in 58.5% after TACE, more frequently than after TARE (43.0%, d = 0.314). Conclusion In conclusion, IATs are promising treatments for improving outcomes for patients with unresectable ICC. To date, TACE and TARE provide similar good outcomes, except for adverse events. Therefore, the decision about techniques is determined by ability to utilize these resources and patient specific factors (liver function or lesion dimension).