Comparative Efficacy and Safety of Transarterial Therapies for Unresectable Neuroendocrine Liver Metastases: A Systematic Review.

PURPOSE: To compare the efficacy and safety of transarterial embolisation, conventional and drug-eluting-bead chemoembolisation, and radioembolisation in adults with unresectable neuroendocrine liver metastases. MATERIALS AND METHODS: Five databases were searched from inception to June 2026 for studies comparing two or more transarterial modalities. Study quality was appraised using the Newcastle-Ottawa Scale or the Cochrane Risk of Bias 2 tool. Because outcome reporting was heterogeneous, findings were synthesised narratively; pooling was undertaken only where two or more studies reported per-arm binary event counts. RESULTS: Fifteen comparative studies including 1,454 patients were identified, 12 of them retrospective. Pooling was feasible for two safety outcomes only, each drawing on two studies: post-embolisation syndrome after chemoembolisation versus embolisation (odds ratio 2.17, 95% confidence interval 0.68-7.00) and severe adverse events after chemoembolisation versus radioembolisation (odds ratio 1.27, 95% confidence interval 0.58-2.79). Adjusted survival estimates with confidence intervals were reported in only four studies. Tumour grade and hepatic tumour burden were the most consistent prognostic factors. No modality showed a consistent survival advantage; radioembolisation offered shorter hospital stays, and evidence for drug-eluting-bead chemoembolisation remained limited amid hepatobiliary toxicity concerns. CONCLUSION: No transarterial modality has been shown to confer a consistent survival advantage, but the evidence is predominantly retrospective and too heterogeneous to establish equivalence. Selection should be individualised within a multidisciplinary team, accounting for disease burden, tumour biology, treatment goals, and safety. Adequately powered prospective trials remain an unmet priority.