Diagnostic performance of CT/MRI LI-RADS radiation treatment response algorithm v2024 for Y-90 radioembolization.
LR-TR-Viable category is highly specific for confirming true tumor viability after Y-90 radioembolization
Diagnostic performance of CT/MRI LI-RADS radiation treatment response algorithm v2024 for Y-90 radioembolization.
To evaluate the performance and inter-reader agreement of the 2024 Liver Imaging Reporting and Data System (LI-RADS) Radiation Treatment Response Algorithm (LR-Radiation-TRA).
This was a single-center retrospective cohort study of patients who underwent Y-90 radioembolization as their most recent locoregional therapy prior to liver transplantation.
A Viable call on imaging reliably confirms true tumor viability on pathology, but many viable tumors are missed.
The average pairwise agreement was 89.8% (85.0 - 92.2%) overall, 88.7% (82.3 - 92.0%) for CT, and 91.2% (83.3 - 94.2%) for MRI.
Due to the low frequency of LR-TR-Viable categorization, inter-reader agreement for Viable versus Nonviable/Nonprogressing was low (intraclass correlation coefficients = 0.269, 95% CI 0.098 - 0.425).
Viability on pathology was 31.2%, 42.1%, and 53.6% for Nonviable, Nonprogressing, and Viable respectively (p = 0.02).
Logistic regression showed higher odds of viability for LR-TR-Viable versus Nonviable lesions (OR = 2.55, 95% CI 1.16 - 5.62, p = 0.02).
LI-RADS-Radiation-TRA v2024 has high specificity for tumor viability after Y-90 radioembolization.
While absolute agreement is high, inter-reader agreement for viability is low, suggesting the need for clearer definitions and training to potentially improve reliability in treatment response assessment for radiation-treated HCC.