Toshiya Shibata, MD Yuji Iimuro, MD Yuzo Yamamoto, MD Iwao Ikai, MD Kyo Itoh, MD Yoji Maetani, MD Fumie Ametani, MD Takeshi Kubo, MD Junji Konishi, MD Index terms: Alcohol ablation, 761.323, 761.1299 Liver, interventional procedures, 761.1299 Liver neoplasms, therapy, 761.12119, 761.323, 761.33 Published online before print 10.1148/radiol.2231010862 Radiology 2002; 223:115–120 Abbreviations: HCC = hepatocellular carcinoma PEI = percutaneous ethanol injection 1 From the Departments of Diagnostic Imaging and Nuclear Medicine (T.S., K.I., Y.M., F.A., T.K., J.K.) and Gastro- enterological Surgery (Y.I., Y.Y., I.I.), Kyoto University Graduate School of Medicine, Shogoin, Sakyoku, Kyoto 606-8507, Japan. Received April 30, 2001; revision requested May 21; re- vision received August 7; accepted September 28. Address correspon- dence to T.S. (e-mail: ksj@kuhp.kyoto-u .ac.jp). © RSNA, 2002 Author contributions: Guarantors of integrity of entire study, all authors; study concepts and de- sign, T.S., Y.I., Y.Y.; literature research, T.S., I.I., Y.M.; clinical studies, T.S., Y.M., F.A.; data acquisition, all au- thors; data analysis/interpretation, T.S., I.I., F.A.; statistical analysis, T.S., Y.M., T.K.; manuscript preparation, T.S., K.I., J.K.; manuscript definition of intellectual content, T.S., T.K., J.K.; manuscript editing, Y.I., I.I., F.A.; manuscript revision/review and final version approval, all authors. CT-guided Transthoracic Percutaneous Ethanol Injection for Hepatocellular Carcinoma Not Detectable with US 1 PURPOSE: To evaluate the safety and effectiveness of computed tomography (CT)-guided percutaneous ethanol injection (PEI) for the treatment of hepatocellular carcinoma (HCC) not detectable with ultrasonography (US). MATERIALS AND METHODS: Between April 1994 and January 2001, 51 patients with 57 HCC nodules not detectable with US underwent CT-guided transthoracic PEI. Complications associated with the transthoracic approach, effectiveness of transthoracic PEI, and prognosis of the patients were evaluated. RESULTS: Seventy-one PEI sessions were performed for 57 nodules. Complications included pneumothorax in 21 sessions (30%) for 19 nodules (33%), moderate pleural effusion in four sessions (6%) for four nodules (7%), and hemoptysis in three sessions (4%) for two nodules (4%). A chest tube was required for pneumothorax in five sessions (7%) for five nodules (9%), and pleural effusion drainage was per- formed in two sessions (3%) for two nodules (4%). Apparent tumor necrosis was noted at CT in 51 nodules (89%). During follow-up (range, 3 months to 5 1 /2 years; mean, 29 months  18 [SD]), local recurrence was seen in seven nodules (12%), three of which received repeat treatment with transthoracic PEI. Twenty-six patients survived, and 25 patients died of multiple tumors, hepatic failure, or rupture of esophageal varices. CONCLUSION: Transthoracic PEI seems to be relatively safe and effective for the treatment of HCC not detectable with US. © RSNA, 2002 Hepatocellular carcinoma (HCC) is one of the most common malignancies in Far East Asia and Southeast Asia (1). Surgical resection is the standard curative treatment for HCC. However, patients with HCC usually have associated cirrhosis or chronic hepa- titis, and thus most patients are not suitable for surgical resection. Several tumor ablation therapies (eg, percutaneous ethanol injection [PEI], radio-frequency ablation, or percutaneous microwave coagulation therapy) have been performed for local con- trol of HCC (2– 6). PEI has been used most widely as an effective, minimally invasive therapy for small HCC 3.0 cm or smaller (2,3). The prognosis of patients with small HCC who are treated with PEI is comparable to that of patients treated with surgical resection (7,8). Standard percutaneous ablation therapy is performed with real-time ultrasonographic (US) guidance. Sometimes some nodules cannot be detected with US, however, such as nodules that are located in the hepatic dome, in the deep region of the liver, and on the liver surface, or small nodules that are 1.0 cm or smaller. Computed tomographic (CT) guidance can also be used with percutaneous ablation therapy (9). Yet, most nodules that are located in the upper portion of the liver, mainly those in the hepatic dome, would require transthoracic introduction of the needle. The purpose of this study was to evaluate the safety and effectiveness of CT-guided trans- thoracic PEI for the treatment of HCC not detectable with US. 115