Inclusion Criteria:  Pathologic or typical imaging based diagnosis of HCC Multiphase CT or MRI within 3 months ahead of procedure No evidence of distant metastasis No contraindications for conventional RFA procedure in our institute, which are uncontrolled coagulopathy (international standard ratio ≥ 1.6, or platelet > 50,000), poor cooperation, unfeasible for sedation, portal vein tumor thrombus, tumor number >4, largest tumor size > 5cm, and tumors abutting portal vein or bile ducts bigger than segmental branches.  Exclusion Criteria:  Lack of multiphase CT or MRI withing 3 months ahead of procedure RFA planned for palliative purpose Diagnosed as non-HCC malignancy Right hepatectomy state