CT-guided treatment of ultrasonically invisible hepatocellular carcinoma.

New techniques of CT-guided management were introduced to ablate ultrasonically invisible hepatocellular carcinomas. In six patients with HCC, a total of six nodules (8-30 mm in diameter) were treated under the guidance of CT. These lesions were not visualized by sonography but were visualized as Lipiodol spots on CT after chemoembolization. Tumor localization was successful in all patients without difficulty, using a thin needle or hookwire under the guidance of CT. Two patients underwent subsequent hepatic resection and/or microwave coagulation therapy (MCT) through a small incision after hookwire placement. Four patients received percutaneous MCT (n = 2) or ethanol injection (PEI) (n = 2) at the time of localization. The postoperative CT with contrast enhancement indicated that tumor ablation was complete in four of the five nodules treated with MCT or PEI. However, in one nodule (30 mm in diameter) treated with PEI, tumor ablation was not complete. There were no complications. There has been no local tumor recurrence 6-46 months after treatment in any of the patients. In conclusion, these CT-guided procedures were effective in treating ultrasonically invisible hepatocellular carcinomas that otherwise would have remained untreated.