Endobiliary radiofrequency ablation (RFA) significantly improves survival in patients with unresectable perihilar cholangiocarcinoma, particularly when performed shortly after biliary drainage.

• RFA within 7 days of drainage is linked to a 66% decrease in 6-month mortality (adjusted hazard ratio 0.34).
• Multiple sessions (two or more) correlate with significantly lower mortality at the 3-month mark (hazard ratio 0.10), though this benefit diminishes over time.

While effective, RFA increases the risk of non-tumor-related biliary obstruction (37.9% vs. 22.1%).