Intraprocedural Transcatheter Intra-arterial Perfusion MRI as a Predictor of Tumor Response to Chemoembolization for Hepatocellular Carcinoma

Rationale and Objectives: To prospectively test the hypothesis that transcatheter intraarterial perfusion magnetic resonance imaging (TRIP-MRI) measured semiquantitative perfusion reductions during transcatheter arterial chemoembolization of hepatocellular carcinoma (HCC) are associated with tumor response. Materials and Methods: Twenty-eight patients (mean age 63 years; range 47-87 years) with 29 tumors underwent chemoembolization in a combined magnetic resonance interventional radiology suite. Intraprocedural tumor perfusion reductions during chemoembolization were monitored using TRIP-MRI. Pre- and postchemoembolization semiquantitative area under the time-signal enhancement curve (AUC) tumor perfusion was measured. Mean tumor perfusion pre- and postchemoembolization were compared using a paired t-test. Imaging follow-up was performed 1-3 months after chemoembolization. We studied the relationship between short-term tumor imaging response and intraprocedural perfusion reductions using univariate and multivariate analysis. Results: Intraprocedural AUC perfusion value decreased significantly after chemoembolization (342.1 vs. 158.6 arbitrary unit, P < 001). Twenty-six patients with 27 HCCs (n = 27) had follow-up imaging at mean 39 days postchemoembolization. Favorable response was present in 67% of these treated tumors according to necrosis criteria. Fifteen of 16 (94%) tumors with 25%-75% perfusion reductions showed necrosis treatment response compared to only 3 of 11 (27%) tumors with perfusion reductions outside the above range (P = 001). Multivariate logistic regression indicated that intraprocedural tumor perfusion reduction and Child-Pugh class were independent factors associated significantly with tumor response (P = 012 and .047, respectively). Conclusion: TRIP-MRI can successfully measure semiquantitative changes in HCC perfusion during chemoembolization. Intraprocedural tumor perfusion reductions are associated with future tumor response.