MRI radiomics and ⁹⁰Y PET dosimetry for predicting hepatocellular carcinoma response after radioembolization

To evaluate treatment response in hepatocellular carcinoma (HCC) following Yttrium-90 (⁹⁰Y) radioembolization by integrating pre-treatment contrast-enhanced magnetic resonance imaging (CE-MRI) radiomics with post-treatment ⁹⁰Y positron emission tomography (PET) dosimetry.

This retrospective study included 57 patients with pathologically confirmed HCC. All patients underwent CE-MRI within 4-6 weeks before ⁹⁰Y transarterial radioembolization (TARE), followed by ⁹⁰Y PET/CT within 24 h post-treatment. Tumor response was assessed at three months using the modified Response Evaluation Criteria in Solid Tumors (mRECIST). Radiomic features extracted from CE-MRI and 24 h tumor absorbed dose parameters from ⁹⁰Y PET/CT were analyzed to predict treatment response, classifying patients as responders or non-responders.

Based on mRECIST criteria, 32 patients were classified as responders (all partial response), while 25 were non-responders (20 stable disease, 5 progressive disease). 24-hour average absorbed dose is independent predictive factors for treatment response (OR = 1.06, p = 0.006). The combined model, incorporating clinical characteristics and MRI-derived radiomic features, achieved a sensitivity of 88% (28/32) [95% CI, 71%-96%], specificity of 68% (17/25) [95% CI, 46%-85%], and accuracy of 79% (45/57) [95% CI, 66%-89%].

The integration of pre-treatment CE-MRI radiomics with post-treatment ⁹⁰Y PET imaging provides complementary insights into tumor biology and therapeutic efficacy. Early tumor absorbed dose metrics derived from ⁹⁰Y PET, together with specific CE-MRI radiomic features, show strong correlations with treatment response and may serve as valuable predictive biomarkers to guide patient stratification and optimize radioembolization strategies in HCC.