Planning Ultrasound for Percutaneous Radiofrequency Ablation to Treat Small (≤ 3 cm) Hepatocellular Carcinomas Detected on CT or MRI: A Multicenter Prospective Study to Assess Factors Affecting Ultrasound Visibility

Abstract

Brief Description of the Purpose of the StudyThe purpose of this study was to assess factors affecting tumor visibility on planning ultrasound (US) for percutaneous radiofrequency ablation to treat small hepatocellular carcinomas (HCCs) primarily detected on CT or MRI.MethodsThe patients referred for planning US for percutaneous radiofrequency ablation between September 2008 and June 2009 were prospectively enrolled from nine institutions in Korea. The first small (≤ 3 cm) single HCC or new single HCC after treatment was included. HCCs which were not visible on planning US were compared with visible HCCs with respect to tumor size, the distance between the tumor and the diaphragm, subcapsular location, etiology of liver disease, liver cirrhosis, macronodular cirrhosis on US, ascites, Child-Pugh class, serum alpha-fetoprotein level, body mass index, previous treatments for HCC, previous chemoembolizations for HCC, institutions, and experience of radiologists.Main ResultsAmong 898 HCCs, 671 (74.7%) were visible on the planning US. In multivariate analysis, tumor size, the distance between the tumor and the diaphragm, liver cirrhosis, and macronodular cirrhosis were statistically significant factors affecting US detection (each p < 0.05).Importance of the ConclusionsSmaller tumors, subphrenic location of the tumor, liver cirrhosis, and macronodular cirrhosis were independent predictors of non-visualized tumors on planning US. Brief Description of the Purpose of the StudyThe purpose of this study was to assess factors affecting tumor visibility on planning ultrasound (US) for percutaneous radiofrequency ablation to treat small hepatocellular carcinomas (HCCs) primarily detected on CT or MRI. The purpose of this study was to assess factors affecting tumor visibility on planning ultrasound (US) for percutaneous radiofrequency ablation to treat small hepatocellular carcinomas (HCCs) primarily detected on CT or MRI. MethodsThe patients referred for planning US for percutaneous radiofrequency ablation between September 2008 and June 2009 were prospectively enrolled from nine institutions in Korea. The first small (≤ 3 cm) single HCC or new single HCC after treatment was included. HCCs which were not visible on planning US were compared with visible HCCs with respect to tumor size, the distance between the tumor and the diaphragm, subcapsular location, etiology of liver disease, liver cirrhosis, macronodular cirrhosis on US, ascites, Child-Pugh class, serum alpha-fetoprotein level, body mass index, previous treatments for HCC, previous chemoembolizations for HCC, institutions, and experience of radiologists. The patients referred for planning US for percutaneous radiofrequency ablation between September 2008 and June 2009 were prospectively enrolled from nine institutions in Korea. The first small (≤ 3 cm) single HCC or new single HCC after treatment was included. HCCs which were not visible on planning US were compared with visible HCCs with respect to tumor size, the distance between the tumor and the diaphragm, subcapsular location, etiology of liver disease, liver cirrhosis, macronodular cirrhosis on US, ascites, Child-Pugh class, serum alpha-fetoprotein level, body mass index, previous treatments for HCC, previous chemoembolizations for HCC, institutions, and experience of radiologists. Main ResultsAmong 898 HCCs, 671 (74.7%) were visible on the planning US. In multivariate analysis, tumor size, the distance between the tumor and the diaphragm, liver cirrhosis, and macronodular cirrhosis were statistically significant factors affecting US detection (each p < 0.05). Among 898 HCCs, 671 (74.7%) were visible on the planning US. In multivariate analysis, tumor size, the distance between the tumor and the diaphragm, liver cirrhosis, and macronodular cirrhosis were statistically significant factors affecting US detection (each p < 0.05). Importance of the ConclusionsSmaller tumors, subphrenic location of the tumor, liver cirrhosis, and macronodular cirrhosis were independent predictors of non-visualized tumors on planning US. Smaller tumors, subphrenic location of the tumor, liver cirrhosis, and macronodular cirrhosis were independent predictors of non-visualized tumors on planning US.