Holmium-166 Radioembolization Is a Safe and Effective Locoregional Treatment for Primary and Secondary Liver Tumors: A Systematic Review and Meta-Analysis.

BACKGROUND/OBJECTIVES: This systematic review and meta-analysis evaluated the effectiveness and the safety of transarterial radioembolization using Holmium-166 microspheres (Ho-166-TARE) for the treatment of primary and secondary liver tumors. The aim of the study was to offer a detailed analysis of clinical outcomes and the potential benefits of this innovative therapy.

METHODS

The study was conducted according to the PRISMA 2020 guidelines. The systematic search was performed in five databases in November 2023 and updated in June 2024. All 16 eligible studies were original research that evaluated Ho-166-TARE. The endpoints analyzed were disease control rate (DCR), overall survival (OS), progression-free survival (PFS), clinical and laboratory adverse events, healthy-liver- and tumor-liver-absorbed doses. The risk of bias was assessed using the MINORS checklist.

RESULTS

The pooled overall disease control rate (DCR) was 72% (95% CI, 46-89%); by mRECIST, it was 93% (95% CI, 71-99%); and by RECIST 1.1, it was 54% (95% CI, 22-83%) at 3-month follow-up. Overall survival (OS) at 3, 6, 12, and 30 months was 98%, 89%, 74%, and 39%, respectively. Severe clinical adverse events were minimal, although some patients showed elevated GGT levels and lymphocytopenia. Tumor-absorbed doses were nearly three times higher than those in healthy liver tissue.

CONCLUSIONS

These findings suggest that Ho-166-TARE is a safe and effective locoregional treatment option for liver tumors, especially in cases where systemic therapy alone is insufficient or surgical resection is not feasible. Further studies are needed to investigate tumor-specific response, optimize dosimetry strategies, and establish standardized protocols for long-term outcome assessment.