Hepatocellular Carcinoma Treated with Percutaneous Radiofrequency Ablation: Evaluated with Sequential Biphasic Helical CT

To determine serial changes in hepatocellular carcinomas (HCCs) treated with percutaneous radiofrequency ablation (PRFA) at long-term serial follow-up biphasic helical computed tomography (CT). Thirty five HCCs (range, 2.1 – 7.0 cm in diameter; mean ± SD, 3.0 ± 1.5 cm) in 27 patients (mean age, 67.2 years) were enrolled in our study. Every patient will received biphasic spiral CT study before and immediately after PRFA, then follow up 3, 6 and 9 months after PRFA for determining the effectiveness of treatment. The serial changes in attenuation, enhancing pattern, shape, and diameter of the thermal lesions were analyzed. Thirty-two (91%) of 35 thermal lesions were low attenuation, with absence of contrast enhancement at immediate and 3 month follow-up CT images, which is suggestive of successful treatment. Peripheral rim enhancement was identified in all of the lesions after treatment (100%). Intralesional air bubbles were seen within 10 thermal lesions (28%). The remaining three lesions (9%) showed peripheral nodular enhancement, suggesting residual viable tumor. Hemoperitoneum was demonstrated in one (4%) patient after PRFA. Eight (29%) of 27 patients had recurrent tumors elsewhere in the liver at follow-up CT study. Biphasic helical CT can provide a diagnostic clue for determining the response of HCC treated with PRFA.