9:20 AM Abstract No. 138 - Factors affecting transarterial chemoembolization response in patients with hepatocellular carcinoma: Imaging-pathology assessment

Abstract

Purpose To evaluate morphologic and pathologic features affecting therapy response in patients with hepatocellular carcinoma (HCC) undergoing transarterial chemoembolization with doxorubicin drug eluting beads (DEB-TACE) prior to liver transplant. Materials and Methods This prospective study included 27 HCCs in 23 patients treated with DEB-TACE (DcBeads®, Biocompatibles, UK) followed by liver transplant. Imaging response was assessed with the mRECIST criteria with areas of non-enhancement used as a surrogate for necrosis. Pathology evaluation of the treated HCCs from the explanted liver was utilized to categorize the magnitude of response to the therapy: Group I, >50% necrosis, Group II, ≤50% necrosis. Pathology data included percent of necrosis after therapy, lesion size, presence of tumor capsule and presence of macro/micro-vascular invasion. Additional variables recorded included: days between DEB-TACE and transplant; number of sessions per nodule; cumulative doxorubicin dose administered to each nodule; and percentage reduction in size of each nodule after therapy. Results The mean percentage of histological necrosis identified overall was 67.8% (95% CI: 56.5%-79.4%). Group I included 18 nodules with a mean percentage of necrosis of 86.2% (60% to 100%). Group II was comprised of 9 nodules with a mean percentage of necrosis of 31.1% (15% to 40%). The mean pre-treatment lesion size by imaging was significantly larger (p=0.030) for Group I [3.2 cm (range 1.5-5.2cm)] when compared to Group II [2.1cm (range 1.5-2.5cm)]. Group I also demonstrated a significantly higher frequency of lesions having a tumor capsule compared to the Group II (p=0.0027) with a tumor capsule present in 78% and 22%, respectively. There was no significant difference between the two groups with respect to vascular invasion, time to transplantation, treatment sessions, and cumulative Doxorubicin dose and percentage reduction in size of the tumors. Conclusion Lesion size and presence of capsule around the tumor are associated with a higher percentage of necrosis after DEB-TACE.