AI-based tumor and organ volumetry predicts early progression after Y-90 radioembolization in liver-dominant metastatic disease.

In patients with liver-dominant metastatic disease undergoing yttrium-90 (⁹⁰Y) transarterial radioembolization (TARE), response assessment remains challenging, particularly in multifocal disease where manual RECIST-based measurements may not adequately reflect overall hepatic tumor burden. In addition, the prognostic relevance of volumetric changes in tumor, liver, and spleen after TARE remains unclear. This retrospective study evaluated automated CT-based whole-liver tumor volumetry as a quantitative imaging biomarker for response assessment and progression risk stratification following TARE. We retrospectively analyzed imaging and clinical data from 57 adults with liver-dominant metastatic disease (colorectal, neuroendocrine, uveal melanoma, and breast cancer) treated with yttrium-90 (⁹⁰Y) resin TARE between January 2012 and December 2022.

Inclusion criteria were age ≥ 18 years, availability of baseline contrast-enhanced CT imaging, and clinical follow-up. Patients undergoing liver resection, transplantation, or additional locoregional therapies during follow-up were excluded. Baseline tumor volume was a strong independent predictor of progression-free survival (PFS), demonstrating excellent discriminatory performance (ROC-AUC 0.91; 95% CI 0.82-1.00). A threshold of 270 mL most accurately identified early progression (