Radioembolization for Colorectal Liver Metastases: Indications and Outcomes

Colorectal cancer remains a leading cause of cancer-related mortality, with the liver representing the predominant site of metastatic spread. For patients with colorectal liver metastases (CRLM) who are not candidates for surgical resection, systemic chemotherapy provides disease control but rarely achieves durable hepatic responses. Radioembolization with yttrium-90 (Y-90) microspheres, delivered via the hepatic artery to exploit the preferential arterial supply of liver tumors, has emerged as an important locoregional option in this setting. This review examines the current evidence base for radioembolization in CRLM, covering patient selection, indications across lines of therapy, dosimetric advances, and clinical outcomes. Appropriate candidacy requires careful assessment of performance status, hepatic tumor burden, tumor biology, lung shunt fraction, and extrahepatic disease extent, with the strongest outcomes observed in patients selected earlier in their disease course. Randomized controlled trials support second-line and third-line use, while unselected first-line use has not demonstrated a benefit. Dosimetric advances, including multicompartment personalized dosing, radiation segmentectomy, and radiation lobectomy, are enabling ablative and bridge-to-resection strategies in appropriately selected patients. Future investigation should prioritize biomarker-driven patient selection, personalized dosimetry, and combination strategies with systemic therapy to determine whether durable hepatic disease control can translate into a survival benefit.