Imaging response predictors following drug eluting beads chemoembolization in the neoadjuvant liver transplant treatment of hepatocellular carcinoma

BACKGROUND: Drug-eluting bead transarterial chemoembolization (DEB-TACE) is an endovascular treatment to release chemotherapeutic agents within a target lesion, minimizing systemic exposure and adverse effects to chemotherapeutics. Therefore, identifying which patient characteristics may predict imaging response to DEB-TACE can improve treatment results while selecting the best candidates. Predictors of the response after DEB-TACE still have not been fully elucidated. This is the first prospective study performed with standardized DEB-TACE technique that aim to identify predictors of radiological response, assessing patients clinical and laboratory characteristics, diagnostic imaging and intraprocedure data of the hepatocellular carcinoma treated in the neoadjuvant context for liver transplantation. AIM: To identify pre- and intraoperative clinical and imaging predictors of the radiological response of drug-eluting bead transarterial chemoembolization (DEB-TACE) for the neoadjuvant treatment of hepatocellular carcinoma (HCC). METHODS: This is prospective, cohort study, performed in a single transplant center, from 2011 to 2014. Consecutive patients with HCC considered for liver transplant who underwent DEB-TACE in the first session for downstaging or bridging purposes were recruited. Pre and post-chemoembolization imaging studies were performed by computed tomography or magnetic resonance. The radiological response of each individual HCC was evaluated by objective response using mRECIST and the percentage of necrosis. RESULTS: Two hundred patients with 380 HCCs were examined. Analysis of the objective response (nodule-based analysis) demonstrated that HCC with pseudocapsules had a 2.01 times greater chance of being responders than those without pseudocapsules (P = 0.01), and the addition of every 1mg of chemoembolic agent increased the chance of therapeutic response in 4% (P < 0.001). Analysis of the percentage of necrosis through multiple linear regression revealed that the addition of each 1mg of the chemoembolic agent caused an average increase of 0.65% (P < 0.001) in necrosis in the treated lesion, whereas the hepatocellular carcinoma with pseudocapsules presented 18.27% (P < 0.001) increased necrosis compared to those without pseudocapsules. CONCLUSION: The presence of a pseudocapsule and the addition of the amount of chemoembolic agent increases the chance of an objective response in hepatocellular carcinoma and increases the percentage of tumor necrosis following drug-eluting bead chemoembolization in the neoadjuvant treatment, prior to liver transplantation.