In our hospital, all patients received computed tomography (CT) or magnetic resonance imaging (MRI) of the liver within one to two months after primary hepatectomy of the HCC to confirm complete tumor clearance. Thereafter, surveillance for recurrent HCC consisted of measurements of serum alpha-fetoprotein (AFP), liver biochemistry, and ultrasonography, CT scan, or MRI scans of the liver every three months. Intrahepatic recurrence was defined as a new lesion with arterial contrast enhancement and portal venous washout. If there was a new lesion less than 1cm and without typical HCC imaging pattern on contrast-enhanced CT or MRI scans, we arranged image studies every three months. If there was a new lesion more than 1cm and without a typical HCC imaging pattern on contrast-enhanced CT or MRI scans, we would arrange a needle biopsy for histological confirmation.