Non-contrast MRI as a surveillance tool for recurrent hepatocellular carcinoma after curative treatment: A prospective multicenter intra-individual comparison trial.

530 Background: Hepatocellular carcinoma (HCC) often recurs following curative treatment, significantly impacting long-term survival. Contrast-enhanced multiphasic computed tomography (CECT) is widely utilized for HCC recurrence surveillance but carries risks such as radiation exposure and adverse reactions to contrast agents. This prospective multicenter trial aimed to compare the accuracy of non-contrast abbreviated magnetic resonance imaging (NC-MRI) with CECT in detecting late recurrent HCC. Methods: This prospective multicenter intra-individual head-to-head comparison trial (study identifier: NCT05690451, KCT0006395) enrolled participants who had undergone curative treatment for HCC and remained recurrence-free for over two years. Participants underwent three rounds of surveillance at 2–6-month intervals using both CECT and NC-MRI. The primary outcome was the detection accuracy of each modality, compared using the McNemar test. Secondary outcomes included detection sensitivity and specificity. Results: A total of 203 participants underwent 528 rounds of paired CECT and NC-MRI, detecting recurrent HCC in 22 participants (10.8%). Among these cases, 21 showed intrahepatic recurrent HCC with a median tumor size of 1.3 cm, and one exhibited aortocaval lymph node metastasis. NC-MRI demonstrated a detection accuracy of 96.6% (196/203), significantly higher than CECT's 91.6% (186/203) (P=0.006). NC-MRI also exhibited significantly higher sensitivity in detecting recurrent HCC compared to CECT (77.3% [17/22] vs. 36.4% [8/22]; P=0.012), while specificity did not differ significantly between NC-MRI and CECT (98.9% [179/181] vs. 98.3% [178/181]; P=0.999). Conclusions: NC-MRI showed significantly higher sensitivity and accuracy in detecting recurrent HCC among patients who had been disease-free for more than two years after curative treatment, establishing it as the preferred surveillance modality for late recurrence. Clinical trial information: NCT05690451 . Contrast enhanced CT Non-contrast MRI Difference, % (95% CI) P-value Estimates, % (n/N) 95% CI, % Estimates, % (n/N) 95% CI, % Accuracy 91.6% (186/203) 87.8-95.5 96.6% (196/203) 94.0-99.1 4.9 (1.7, 8.2) 0.006 Sensitivity 36.4% (8/22) 14.5-58.2 77.3% (17/22) 58.3-96.3 40.9 (16.8, 65.0) 0.012 Specificity 98.3% (178/181) 96.5-100 98.9% (179/181) 97.4-100 0.6 (-0.5, 1.6) 0.999