3:54 PM Abstract No. 133 Microwave ablation of pericardial hepatic lesions

Abstract

Microwave ablation (MWA) has been shown to be effective in treatment of primary hepatic cellular carcinoma (HCC) and liver metastasis from colorectal cancer. The purpose of this study is to demonstrate the safety and efficacy of MWA of liver lesions including primary HCC and liver metastasis with final ablation zone that is ≤ 5 mm from the pericardium. A retrospective study was performed on all patients who had MWA from January 2015 to June 2019 at a single tertiary center. Exclusion criteria include lesions with ablation zones >5 mm from pericardium. CT and MR imaging obtained prior, during and after procedure along with procedure reports were used to identify tumor size, ablation zone size, and distance from pericardium, complications, and recurrence rates for each patient. A total of 379 MWA sessions during study time frame. A total of 11 patients were identified to have lesions with ablation zones within ≤5 mm of pericardium. Of the 11 patients identified (with ablation zone ≤5 mm from pericardium), 3 patients had liver metastasis from colorectal cancer and the remainder of 8 patients had primary HCC. Only 1 patient had minor complication of small pneumothorax post procedure that did not require intervention, and the remainder 10 patients did not develop any complications as defined by SIR criteria. No cardiac arrhythmias were recorded. None of the patients were readmitted for MWA complications at 1-month post procedure period. 2 of the patients were treated with MWA for a residual tumor after TACE, and 1 of these patients had recurrence at 1 month at the same location. 2 patients had no follow-up imaging, 1 patient had liver transplant prior to follow-up imaging was performed, and the remaining patients had no residual disease or local recurrence at 1, 3, and 6-month follow-up. Overall disease progression within the liver at a different (7)/same location (1) from ablation site occurred in 73% of patients ranging from 1-6 months from procedure. MWA of liver lesions close to pericardium is safe and effective; however, it can be technically challenging. One of the limitations of the study was that proximity to pericardium was estimated with combination of different CT imaging protocols.