Interventional strategies for inferior phrenic artery management in yttrium‑90 selective internal radiation therapy for hepatocellular carcinoma: A single‑center retrospective study

Extrahepatic collateral supply from the inferior phrenic artery (IPA) is frequently observed in patients with hepatocellular carcinoma (HCC) undergoing yttrium-90 selective internal radiation therapy ( 90 Y-SIRT). Currently, no standardized IPA management algorithm has been established. This study aimed to propose stratified interventional strategies for IPA and compare the safety and oncological outcomes between two mainstream approaches. A retrospective analysis was performed on 290 consecutive unresectable HCC patients treated with 90 Y-SIRT between October 2022 and December 2025. Patients with suspected IPA tumor perfusion on pre-treatment cross-sectional imaging were enrolled. All patients underwent superselective IPA catheterization under combined digital subtraction angiography (DSA) and cone-beam computed tomography (CBCT). According to tumor volume and anatomical characteristics of non-target vessels, patients were divided into direct Y-90 infusion group and IPA embolization group. Tumor response and treatment-related adverse events were assessed and compared. A total of 78 patients with angiographically confirmed IPA tumor supply were finally enrolled, including 45 patients in the IPA Y-90 infusion group and 33 in the IPA embolization group. The median administered radioactivity via IPA was 0.3 GBq. Based on modified Response Evaluation Criteria in Solid Tumors (mRECIST), the objective response rates (ORRs) at 1 and 3 months were 60.0% and 82.3% in the infusion group, versus 48.5% and 69.7% in the embolization group. The compensatory distribution rate of Y-90 microspheres in the original IPA-perfused regions reached approximately 88.0% after IPA embolization. Only mild, reversible thoracic adverse events were noted in both groups, with no severe treatment-related complications. DSA-CBCT combined evaluation is essential for pre-procedural IPA anatomical assessment. Direct Y-90 microsphere infusion via IPA yields superior tumor control when non-target vessels are manageable and IPA-perfused tumor volume ≥ 20 mL. IPA embolization is a reliable alternative for patients with untreatable non-target branches or tumor volume < 20 mL. Both strategies demonstrate favorable safety profiles. The proposed stratified algorithm represents a preliminary approach that warrants further external validation for IPA management during 90 Y-SIRT for HCC.