OE MRI to Predict Treatment Response After TACE in HCC Patients

This will be a single-center, prospective, study to evaluate dOE-MRI in patients undergoing TACE for HCC according to the clinical standard of care. This protocol has already been approved by the local research ethics committee. Adult patients with HCC \>25mm undergoing TACE are enrolled. Imaging will be performed on a 3T whole-body MRI, dOE-MRI will be acquired with a free-breathing T1-weighted dynamic acquisition with respiratory motion-resolved compressed sensing reconstruction (XD-GRASP). Tumor hypoxia will be assessed by measuring changes in the longitudinal relaxation rate (∆R1) from baseline (21% O2) and during a hyperoxic respiratory challenge (FiO2 100%). Tumor response will be assessed by mRECIST and LI-RADS Treatment Response Assessment v2024. Descriptive statistics for the level of ∆R1 pre- and post- treatment will be presented using means and standard deviations. Progression-free survival and overall survival will be evaluated by using the Cox proportional hazard model and Kaplan-Meier method. Receiver operating characteristic (ROC) curve analysis at one year will be performed and the optimal cutoff threshold of ∆R1 will be calculated using Youden's index.

• Hypoxic level of HCC according to R1 variations during an oxygen challenge on MRI scans after treatment [Time frame: Oxygen-enhanced MRI is performed 4-6 weeks after treatment. Patients are followed up 2 years after treatment.]