Tatsuya Shiraki

Contrast-Enhanced Ultrasonography in the Diagnosis of Solid Renal Tumors

The purpose of this study was to evaluate the usefulness of contrast‐enhanced ultrasonography (CEUS) in the diagnosis of solid renal tumors.

Prediction of sustained response to low-dose pegylated interferon alpha-2b plus ribavirin in patients with genotype 1b and high hepatitis C virus level using viral reduction within 2 weeks after therapy initiation

Aim:  Continuation of pegylated interferon (PEG‐IFN) plus ribavirin at the recommended dose is difficult in elderly patients and/or patients with cytopenia or complications. Whether the therapeutic efficacy of low‐dose PEG‐IFN plus ribavirin therapy could be predicted based on virological response within 2 weeks of therapy initiation was evaluated.

Altered cytokine levels and increased CD4+CD57+ T cells in the peripheral blood of hepatitis C virus-related hepatocellular carcinoma patients

Although CD57+ lymphocytes are closely correlated with prognosis in various cancers, the role of subsets of CD57+ cells in hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC) is unclear. In the present study, peripheral blood (PB) from HCV-related HCC patients was analyzed. Plasma cytokine levels and in vitro cytokine-producing capabilities were analyzed with enzyme-linked immunosorbent assays, and CD57+ cell subsets were studied using a multi-color FACS system. Interferon (IFN)-γ was undetectable in the plasma of patients with tumors at any stage, whereas the plasma levels of tumor necrosis factor (TNF)-α, interleukin (IL)-10 and IL-18, but not that of IL-12, were significantly higher in stage IV patients compared to patients with earlier-stage tumors. In contrast, the IFN-γ-producing capability of PB was highest in stage I patients and gradually decreased with tumor progression. The IL-10-, IL-18- and IL-12-producing capabilities of PB increased from stage I to III. However, PB-TNF-α, IL-10- and IL-18-producing capabilities were reduced in stage IV patients, probably due to repeated anti-cancer treatments. The percentage of CD4+CD57+αβTCR+ cells (CD4+CD57+ T cells) in peripheral blood lymphocytes (PBLs) increased with tumor progression. Moreover, the percentage of CD4+CD57+ T cells in PBLs and the ratio of CD4+CD57+ T cells to CD4+αβTCR+ cells (CD4+ T cells), but not that of CD4+CD57+ T cells to CD57+αβTCR+ cells (CD57+ T cells), showed a significant inverse correlation with PB-IFN-γ-producing capability. The present results suggest that an increase in CD4+CD57+ T cells controls the capability of PB to produce the anti-tumor cytokine IFN-γ and that PB-IFN-γ production is impaired with HCC tumor progression.

Assessment of malignant potential of small hypervascular hepatocellular carcinoma using B-mode ultrasonography.

Aim:  Evaluation of malignant potential is important to determine the treatment strategy for small hepatocellular carcinoma (HCC). The aim of the present study was to establish a method of assessing the malignant potential of small hypervascular HCC using B‐mode ultrasonography.

Multifocal nodular fatty infiltration of the liver mimicking metastatic liver tumors: diagnosis using the liver-specific late phase of Levovist-enhanced sonography.

Focal nodular fatty infiltration of the liver is a pseudotumor visualized as a highly echoic lesion on sonography. On computed tomography (CT), focal nodular fatty infiltration is generally characterized by a low-density area with no mass effect. 1 Although focal nodular fatty infiltration must be differentiated from primary liver cancer, a metastatic liver tumor, or hepatic hemangioma, this can be difficult with CT or sonography alone. When differential diagnosis is difficult from imaging investigations alone, biopsy proof of the tumor is necessary before therapy is commenced. The appearance of numerous small multifocal nodular fatty infiltrations in both hepatic lobes may mimic that of metastatic liver disease, leading to incorrect therapy. Particularly if the patient has had malignant disease in the past, multifocal nodular fatty infiltrations may be misdiagnosed, and incorrect therapy may be performed without adequate examination or differential diagnosis of the primary lesion. Although magnetic resonance imaging (MRI) and fine-needle biopsy are reportedly useful in diagnosing focal fatty infiltration of the liver, 2-4 the value of enhanced sonography has not been reported in this situation. We encountered a case of multifocal nodular fatty infiltration in which findings of the late parenchymal phase of enhanced sonography with Levovist (SH U 508A; Schering AG, Berlin, Germany) were useful in ruling out malignancy.

Ultrasonogram of hepatocellular carcinoma is associated with outcome after radiofrequency ablation

AIM To investigate the association between B-mode ultrasound classification of small hepatocellular carcinoma (HCC) and outcome after radiofrequency ablation (RFA). METHODS Ninety-seven cases of HCC treated using RFA between April 2001 and March 2006 were reviewed. Ultrasound images were classified as follows: type 1, with halo (n = 29); and type 2, without halo (n = 68). Type 2 was further categorized into three subgroups: type 2a, homogenous hyperechoic (n = 9); type 2b, hypoechoic with smooth margins (n = 43); and type 2c (n = 16), hypoechoic with irregular or unclear margins. Patients with type 2a HCC were excluded from analysis due to the small number of cases. RESULTS Two year recurrence rates for type 2b, type 1 and type 2c were 26%, 42% and 69%, respectively, with significant differences between type 2b and type 2c (P < 0.01), and between type 1 and type 2c (P < 0.05). Five year survival rates were 89%, 43% and 65%, respectively. Survival was significantly longer for type 2b than for other types (type 1 vs type 2b, P < 0.01; type 2b vs type 2c, P < 0.05). On univariate analysis, factors contributing to recurrence were number of tumors, tumor stage, serum level of lens culinaris agglutinin-reactive alpha-fetoprotein and ultrasound classification (P < 0.05). Factors contributing to survival were tumor stage and ultrasound classification (P < 0.05). Multivariate analysis identified ultrasound classification as the only factor independently associated with both recurrence and survival (P < 0.05). CONCLUSION B-mode ultrasound classification of small HCC is a predictive factor for outcome after RFA.

Potent induction therapy with interferon and ribavirin combination therapy does not achieve a higher sustained virological response rate in chronic hepatitis C with genotype 1b and high hepatitis C virus RNA level

Aims:  To compare twice‐daily interferon (IFN)‐β administration and once‐daily IFN‐α‐2b administration as induction therapy in ribavirin combination therapy in chronic hepatitis C with a high viral load of genotype‐1b hepatitis C virus (HCV).