• hepatocellular carcinoma
• interventional radiology
• microwave ablation
• orthotopic liver transplant

To assess the efficacy of percutaneous microwave ablation (MWA) of hepatocellular carcinoma (HCC) evaluating pathological examination after total hepatectomy in patients submitted to orthotopic liver transplantation (OLT).

Treatment outcomes were considered in 29 patients who underwent MWA for 31 HCC nodules and were subsequently submitted to OLT, between 2012 and 2017. Patients were submitted to MWA as a bridge therapy to OLT or before being included in the waiting list for OLT. Only nodules ≤40mm in size were considered eligible for MWA. Two experienced interventional radiologist performed MWA using a 2.45GHz system (HS AMICA®, HS HOSPITAL SERVICE SpA, Italy) with 14-gauge and 16-gauge antennas.

Nodule size ranged 12-40mm (23.9mm ± 7.9mm). All the nodules had complete radiological response at CT performed 1 month after treatment and at 3 months intervals thereafter. At pathology 21/31 (68%) nodules had complete necrosis (nodule size: 21.52mm ± 6.82 mm), while 10 nodules with complete radiological response had viable tumor at pathology. In 5/10 nodules with viable tumor the necrosis was >90%. Of the 10 nodules >3 cm, 6 were completely necrotised and 4 had necrosis >90%. Mild significant correlation between nodule size and complete pathological response was found (p=0.003), with a linear relationship between antenna's caliber (14G) and complete pathological response.

Results of our studies confirmed the efficacy of MWA in treatment of HCC, even in nodules >3cm. Compared to the results of radiofrequency ablation in published series with histopathological correlation, MWA seems to provide higher rates of complete necrosis.