Kinuyo Hatanaka

Differential Diagnosis of Hepatic Tumors: Value of Contrast-Enhanced Harmonic Sonography Using the Newly Developed Contrast Agent, Sonazoid

Objective: To clarify the value of contrast-enhanced harmonic ultrasonography (US) with Sonazoid, a second-generation US contrast agent, in the differential diagnosis of liver tumors compared to dynamic CT. Methods: A total of 249 hepatic nodules in 214 patients were studied; these included 177 hepatocellular carcinomas (HCCs), 42 liver metastases, 20 liver hemangiomas, 6 dysplastic nodules and 4 focal nodular hyperplasias (FNHs). After the injection of Sonazoid, nodules were scanned using real-time contrast-enhanced harmonic US in the vascular phases, i.e. the early and late vascular phases, and the Kupffer phase. Results: Six enhancement patterns were identified to be significant for the differential diagnosis of hepatic tumors. In HCCs, the presence of intratumoral vessels supplied from the periphery and fast washout (sensitivity, 96.6%; specificity, 94.4%) were the most typical characteristics. In metastases, the presence of rim-like enhancement with peripheral tumor vessels (sensitivity, 88.1%; specificity, 100%) was the typical pattern. In hemangiomas, the presence of intratumoral hypoperfusion images with globular or cotton wool-like pooling, which continue to the late vascular phase (sensitivity, 90.0%; specificity, 99.6%), was typical. In dysplastic nodules, the presence of portal enhancement without arterial supply in the early vascular phase and the presence of intratumoral uptake in the Kupffer phase (sensitivity, 83.3%; specificity, 100%) were the most typical patterns. In FNHs, the presence of a spoke-wheel pattern in the early vascular phase with dense staining in the late vascular phase, and positive uptake within the nodule in the Kupffer phase (sensitivity, 100%; specificity, 100%) were the most typical patterns. Conclusion: Contrast-enhanced harmonic US with Sonazoid allowed intimate vascular and Kupffer imaging and, therefore, is useful for the differential diagnosis of hepatic tumors.

Sonazoid-enhanced ultrasonography for diagnosis of hepatic malignancies: comparison with contrast-enhanced CT.

Objective: The purpose of this study was to assess the usefulness of Sonazoid-enhanced ultrasonography (US) in the diagnosis of hepatic malignancies in comparison with contrast-enhanced CT findings. Methods: A total of 74 patients with 113 hepatic tumors having or highly suspected of having malignancies were enrolled. These hepatic nodules were diagnosed by typical findings of imaging such as contrast-enhanced CT, dynamic MRI or Sonazoid-enhanced US, tumor markers and histological examinations after surgical resection or biopsy. Results: 108 nodules were diagnosed as malignant tumors (hepatocellular carcinoma: n = 90; metastasis: n = 16; intrahepatic cholangiocarcinoma: n = 2) and the remaining five tumors were diagnosed as benign tumors (dysplastic nodules: n = 5). Sonazoid-enhanced US correctly depicted the presence or absence of tumors in 74 patients, with a sensitivity of 95.4%, an accuracy of 94.7%, and a positive predictive rate of 99%. Contrast-enhanced CT depicted the malignancies with a sensitivity of 85.2%, an accuracy of 82.3%, and a positive predictive rate of 95.8%. There were significant differences between Sonazoid-enhanced US and contrast-enhanced CT for sensitivity and accuracy (both p < 0.05). Conclusion: Sonazoid-enhanced US has a higher sensitivity and accuracy for the diagnosis of hepatic malignancies than contrast-enhanced CT.

Long-Term Interferon Maintenance Therapy Improves Survival in Patients with HCV-Related Hepatocellular Carcinoma after Curative Radiofrequency Ablation

Objective: To assess whether low-dose, long-term maintenance interferon (IFN) therapy inhibits recurrence after complete ablation of hepatocellular carcinoma (HCC) and improves patient survival. Methods and Patients: From June 1999 through May 2006, a total of 127 HCC cases that met the requirements of both tumor diameter 3 cm or less, and number of tumors three or fewer, were curatively treated by radiofrequency ablation therapy (RFA). Among them, 43 patients received three million IU of IFN-α2b twice per week or pegylated IFN-α2a 90 µg once per week or once per 2 weeks without discontinuation (IFN maintenance group). The remaining 84 patients, whose sex, age, and platelet counts were randomly matched to those of the IFN maintenance group, did not receive IFN treatment (control group). Results: Cumulative first, second, and third recurrence rates were significantly reduced in the IFN maintenance group compared with the control group by Kaplan-Meier estimate. The 5-year survival rate was 66% for the control group and 83% for the IFN maintenance group (p = 0.004). Multivariate analysis using the Cox proportional hazards model identified IFN maintenance therapy as an independent risk factor for survival, and the risk ratio was 0.21 (95% CI: 0.05–0.73). In conclusion, low-dose, long-term maintenance IFN therapy after curative RFA therapy of HCC significantly inhibits recurrence, and consequently improves patient survival.

Newly Developed Novel Ultrasound Technique, Defect Reperfusion Ultrasound Imaging, Using Sonazoid in the Management of Hepatocellular Carcinoma

The aim of this study is to clarify the usefulness of defect reperfusion ultrasound (US) imaging using Sonazoid in the management of hepatocellular carcinoma (HCC). A total of 33 HCC nodules and 34 local recurring nodules after radiofrequency ablation (RFA), which could not be identified by B-mode US but were depicted by dynamic CT, were studied by defect reperfusion US imaging with Sonazoid. In addition, Kupffer phase Sonazoid-enhanced US in combination with defect reperfusion US imaging were used for screening HCC in 262 consecutive cirrhotic patients. As a result, 33 US undetectable HCC nodules and 34 local recurring HCC nodules were successfully confirmed by Sonazoid-enhanced US with defect reperfusion imaging. Subsequently, RFA was successfully performed in all of 67 HCC nodules with a Sonazoid-enhanced US guidance. A total of 7 small HCCs were depicted and confirmed as HCCs by Kupffer phase surveillance and defect reperfusion US imaging. In conclusion, defect reperfusion US imaging is extremely useful in the depiction and confirmation of US undetectable HCCs as well as in the surveillance of HCC in cirrhotic patients.

Response evaluation of transcatheter arterial chemoembolization in hepatocellular carcinomas: the usefulness of sonazoid-enhanced harmonic sonography.

Background: The purpose of this study was to investigate if Sonazoid-enhanced harmonic ultrasonography (US) could be used to evaluate the responses of hepatocellular carcinomas (HCCs) to treatment with transcatheter arterial chemoembolization (TACE). Patients and Methods: Forty-three HCCs that had been treated by TACE were evaluated by Sonazoid-enhanced harmonic US and dynamic computed tomography (CT) approximately 1 week after their treatment. The detection rates of residual tumor blood supply using the two modalities were compared. Two months after chemoembolization, 16 of the 43 HCCs, which had no additional local treatment, were followed up with dynamic CT. The results of contrast-enhanced harmonic US and dynamic CT 1 week after chemoembolization were analyzed and compared with follow-up dynamic CT results. Results: The detection rates of positive enhancement with Sonazoid-enhanced harmonic US and dynamic CT 1 week after TACE were 25 (58.1%) of 43 lesions and 17 (39.5%) of 43 lesions, respectively. Sonazoid-enhanced harmonic US was significantly more sensitive than dynamic CT in depicting the residual tumor blood supply to HCCs 1 week after TACE (p < 0.01; χ2 test). The Sonazoid-enhanced harmonic US results of the 16 lesions 1 week after chemoembolization were consistent with the follow-up results of dynamic CT 2 months after chemoembolization. Conclusions: Sonazoid-enhanced harmonic US appears to be a highly sensitive and accurate modality for evaluating responses of HCCs shortly after TACE.

Radiofrequency ablation guided by contrast harmonic sonography using perfluorocarbon microbubbles (Sonazoid) for hepatic malignancies: an initial experience.

Aim: Conventional contrast harmonic sonography has the technical problem of a short enhancement time during targeting of hepatic malignancies for radiofrequency (RF) ablation. This study investigated the effectiveness of contrast harmonic sonographic guidance using perfluorocarbon microbubbles (Sonazoid) during RF ablation of hepatic malignancies.

Percutaneous Radiofrequency Ablation of Sonographically Unidentifiable Liver Tumors

Objective: The purpose of this study was to evaluate the safety and feasibility of a real-time integrated system with computed tomography (CT) and sonographic images for radiofrequency (RF) ablation of hepatic malignancies poorly defined on B-mode sonography, and to clarify the suitable phase of CT images for using this virtual sonography. Methods: Between September 2004 and December 2004, 12 patients with 16 hepatocellular carcinomas and two metastatic lesions arising from colorectal adenocarcinoma (n = 1) and rectal carcinoid (n = 1) were treated. The maximum diameter of nodules ranged from 1.0 to 2.5 cm (mean ± SD; 1.5 ± 0.6 cm) on CT images. Results: Complete tumor necrosis was achieved in a single session in 19 lesions (90%), while a second session was required for the remaining two lesions (10%). Portal phase multi-planar reconstruction images were displayed under a suitable position corresponding to the ultrasound images in 9 patients (HCC = 7, metastasis = 2), and arterial phase multi-planar reconstruction images were displayed in the 3 remaining patients with hepatocellular carcinoma. Conclusion: Percutaneous RF ablation guidance using virtual sonography is an effective treatment for patients with hepatic malignancies. The portal phase of CT images may be the most suitable to indicate the 3-dimensional relationship between the liver vasculature and tumors on virtual sonography.

Clinical characteristics of NonBNonC- HCC: Comparison with HBV and HCV related HCC.

Objective: To clarify the frequency and trends of both HBsAg and HCVAb negative hepatocellular carcinoma (NonBNonC-HCC) in all HCC, to clarify the etiology of NonBNonC-HCC, and to elucidate the clinical characteristics of NonBNonC-HCC compared with those of HBsAg-positive HCC (B-HCC) and HCVAb-positive HCC (C-HCC). Methods: A total of 2,542 patients with HCC examined at three institutions between 1991 and 2004 were categorized based on their serum viral antigen/antibody positivities, and compared between groups for the etiology, annual trend of the incidence, and clinical characteristics. Results: For the etiology, C-HCC was most prevalent, followed by B-HCC, NonBNonC-HCC, and both HBsAg and HCVAb-positive HCC (BC-HCC) in order. For survival, C-HCC had the most favorable prognosis, followed by NonBNonC-HCC, and B-HCC patients had the poorest prognosis in the three groups (C-HCC, B-HCC, and NonBNonC-HCC). In tumor-node metastasis (TNM) stages I+II, however, NonBNonC-HCC patients took the most favorable clinical course. The incidence of NonBNonC-HCC in all HCC was 5–8% from 1991 to 1998, and has increased to 10–12% since 1999. Additionally, the incidence of HBcAb-positive HCC in NonBNonC-HCC declined each year. Among NonBNonC-HCC patients, the morbidity of diabetic complications was significantly higher in HBcAb-negative patients than in HBcAb-positive patients. Conclusion: Although the incidence of NonBNonC-HCC among all HCC has an increasing trend recently, the incidence of HBcAb-positive HCC in NonBNonC-HCC has a tendency of decreasing. This fact suggest its etiology might be changing from occult HBV related HCC to unknown etiology such as nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH) related HCC. The prognosis of NonBNonC-HCC was fairly good if the HCC was found in its early stage.

Double-contrast ultrasound: a novel surveillance tool for hepatocellular carcinoma.

To the Editor: Hepatocellular carcinoma (HCC) is the third most common cause of cancer death worldwide. Practice guidelines in the West (1) and East (2) recommend ultrasound (US) surveillance as a first-line test. However, despite the performance of periodic surveillance, some HCCs are still detected at advanced stages because of the coarse liver parenchyma. Furthermore, even HCCs detected at early stages, such as single nodular HCCs smaller than 3 cm, still show high annual recurrence rates (15–20%) after resection or ablation (3). These phenomena are attributed to the tumor biology of HCCs, which frequently metastasize via the portal vein even when they are less than 2 cm (4). Detection of much smaller HCC nodules that do not yet have microsatellites or vascular invasion is an urgent clinical need.

Imaging of Hepatocellular Carcinoma: Qualitative and Quantitative Analysis of Postvascular Phase Contrast-Enhanced Ultrasonography with Sonazoid

Purpose: To evaluate the usefulness of vascular phase images of contrast-enhanced ultrasonography (CE-US) with Sonazoid for hepatocellular carcinomas (HCCs), a retrospective, comparative study was conducted of images of HCCs obtained by CE-US and superparamagnetic iron oxide (SPIO) magnetic resonance imaging (MRI) and evaluated qualitatively and quantitatively. Methods: Seventy-seven patients with 88 HCCs who received CE-US and SPIO-MRI were reviewed. The ratio of the echogenicity of the tumor and nontumor areas was calculated with postvascular phase CE-US (postvascular phase ratio). The ratio of the intensity of the nontumor to tumor areas on SPIO-enhanced MRI (SPIO intensity index) was also calculated. The Pearson correlations were calculated for all values between the postvascular phase ratio and SPIO intensity index for quantitative comparison. These images were also compared qualitatively for the detection rate of the tumors. Results: The sensitivities of CE-US and SPIO-MRI in detecting tumors were 98 and 95%, respectively (nonsignificant, χ2 test). The postvascular phase ratio correlated with the SPIO intensity index for HCCs (Pearson r = 0.803, p < 0.05). The image conformity of the result from the liver parenchymal phase CE-US and SPIO-MRI was 92%. Dedifferentiation spots of nodule-in-nodule HCCs were detected in 4 (80%) of 5 on postvascular phase images of CE-US, and in 2 (40%) of 5 on SPIO-MRI (nonsignificant, χ2 test). Conclusions: Postvascular phase images of CE-US with Sonazoid appear promising as an alternative to SPIO-enhanced MRI. Further study cases are needed to confirm the usefulness of postvascular phase images of CE-US compared to SPIO-MRI for the detection of dedifferentiation foci in hepatic tumors.