4:21 PM Abstract No. 136 Use of contrast-enhanced ultrasound after computed tomography–guided microwave ablation for hepatocellular carcinoma in our practice with magnetic resonance imaging and pathologic correlation

Abstract

Contrast-enhanced ultrasound (CEUS) is a low cost and effective imaging modality that is accessible immediately post procedure which allows the clinician to instantly perform additional ablation of the tumor if a residual tumor is detected. CEUS can be an alternative to contrast enhanced CT in patients with underlying renal disease or iodine allergy. The purpose of this abstract is to share our experience with use of contrast enhanced ultrasound after microwave ablation for HCC with MRI correlation and posttransplant pathology. This is a retrospective analysis of 13 patients in an IRB-approved study conducted at our institution from 2017-2019. The patients were identified during liver tumor board with diagnosis of hepatocellular carcinoma (HCC) amenable to microwave ablation. These patients underwent CT-guided microwave ablation of HCC. Immediately post procedure patients underwent CEUS to evaluate for residual tumor, which was reported by an expert ultrasound radiologist providing us with instant feedback regarding residual tumor. Patients underwent MRI one month post procedure to evaluate for residual tumor within the treatment bed. Pathology reports were obtained for the patients that received liver transplants and radiologic and pathologic correlation was made to the treatment site. 7 postablation CEUS examinations demonstrated complete response to therapy with concordant results on follow-up MRI. 3 went on to have a liver transplant with complete or near complete response. Four post ablation CEUS examinations were read as suboptimal. Follow-up MRI for 3 showed complete response and 1 showed viable tumor in the treatment cavity. 1 patient had transplant before MRI. Transplant pathology showed complete response. Out of 13 patients 1 study was discordant with no enhancement seen on CEUS at the time of ablation with viable tumor on MRI. See Table 1. Preliminary data demonstrates congruence between post ablation CEUS and follow-up MRI or CEUS with no residual tumor in the treatment bed in 7 of 13 of our patients. Artifact and operator dependence can limit evaluation however CEUS is still an inexpensive and useful tool post ablation.Table 1Summary of Patients with Postablation CEUS and MRI13 Patients7 patients: concordant CEUS and MRI complete response3 patients transplanted2 pathology reports with complete response; 1 with partial response4 patients: postablation CEUS suboptimal because of artifact3 compete response; 1 viable tumor1 transplant with complete response1 patient: CEUS no MRI because of transplantPathology report shows complete response1 patient: discordant CEUS and MRI Open table in a new tab