Locoregional chemoembolic delivery: prediction with transcatheter intraarterial perfusion MRI.

ABSTRACT

OBJECTIVE: To our knowledge there is currently no quantitative preprocedural method for predicting the distribution and selectivity of delivery of chemoembolic material during trans-arterial chemoembolization. Transcatheter intraarterial perfusion MRI has been developed as a method of quantifying hepatic arterial perfusion. The purpose of this study was to investigate whether findings at transcatheter intraarterial perfusion MRI before chemoembolization can be used to predict uptake of the chemoembolic material delivered during chemoembolization. SUBJECTS AND METHODS: We compared quantitative prechemoembolization transcatheter intraarterial perfusion MRI parameters with analogous postchemoembolization CT chemoembolic distribution parameters and analyzed correlation using the Pearson correlation coefficient. These MRI and CT parameters included volume of distribution (a metric for volumetric liver perfusion or therapeutic agent delivery) and chemoembolic delivery selectivity factor (a ratio of volume-normalized tumor to background signal intensity that indicates the selectivity of chemoembolic delivery). RESULTS: Twenty-four hepatocellular carcinomas were targeted in 18 patients (14 men, four women; mean age, 66 years), and segmental or lobar chemoembolization with intraprocedural transcatheter intraarterial perfusion MRI was successful in all 18. Transcatheter intraarterial perfusion MRI and CT volume of distribution did not differ significantly (MRI, 233 cm(3); CT, 235 cm(3); p = 0.857). Transcatheter intraarterial perfusion MRI selectivity factor was an underestimate of CT selectivity factor (MRI, 0.20; CT, 0.25; p = 0.005). Prechemoembolization transcatheter intraarterial perfusion MRI and postchemoembolization CT volume of distribution (r = 0.93; p < 0.001) and selectivity factor (r = 0.95; p < 0.001) showed significant correlation. CONCLUSION: Tumor perfusion measured with transcatheter intraarterial perfusion MRI is predictive of uptake of chemoembolic material before delivery. This MRI technique may have utility as a method of quantifying delivery of the therapeutic agent during chemoembolization and, potentially, other liver-directed locoregional therapies.