Retreatment with peginterferon α-2a + ribavirin in patients who failed previous peginterferon α-2b + ribavirin combination therapy.

BACKGROUND/AIMS: Peginterferon (PEG-IFN) + ribavirin (RBV) combination therapy is the current standard of care for chronic hepatitis C. However, more than half of the patients cannot achieve sustained viral response (SVR). In Japan, the clinical benefit of retreatment with PEG-IFN + RBV combination retreatment is still unknown. METHODS: We collected clinical data in 106 chronic hepatitis C patients who failed to achieve SVR with PEG-IFNα-2b + RBV combination therapy and were retreated with PEG-IFNα-2a + RBV. This retrospective study examined the efficacy of retreatment with PEG-IFNα-2a + RBV by evaluating the time to eradication of hepatitis C virus RNA, early virological response (EVR), and SVR. We compared the results of the previous therapy and retreatment in terms of efficacy and analyzed the factors influencing SVR. RESULTS: The SVR rates in the non-responders and relapsers were 11 and 53%, respectively. EVR and prolonged treatment duration were associated with SVR. We also found that a prior response to PEG-IFN + RBV therapy was more important than the Interleukin-28B genotype for predicting the response to retreatment. CONCLUSIONS: Retreatment with PEG-IFNα-2a + RBV should be considered for relapsers and partial responders. Our results suggest that prolonged administration is also favorable for EVR cases to attain a higher SVR.

Oral branched-chain amino acid granules reduce the incidence of hepatocellular carcinoma and improve event-free survival in patients with liver cirrhosis.

BACKGROUND: It has been reported that branched-chain amino acid (BCAA) supplementation can improve nutritional status and prevent liver-related complications in patients with decompensated cirrhosis. We investigated the effects of oral BCAA supplementation on the incidence of hepatocellular carcinoma (HCC) and liver-related events in patients with compensated and decompensated cirrhosis. METHODS: We enrolled 211 patients with cirrhosis including 152 patients with Child-Pugh A cirrhosis, but no history of HCC. Of these, 56 received oral administration of 12 g/day BCAA for ≥6 months (BCAA group), and 155 were followed-up without BCAA treatment (control group). The HCC occurrence and event-free survival rates were compared between the two groups. We used a propensity score analysis to overcome selection bias of this retrospective analysis. RESULTS: The HCC occurrence rate was significantly lower and event-free survival rate was significantly higher in the BCAA group than in the control group. Multivariate analyses showed BCAA supplementation was significantly associated with reduced incidence of HCC (hazard ratio (HR) 0.416, 95% confidence interval (CI) 0.216-0.800, p = 0.0085). BCAA supplementation also reduced the incidence of liver-related events in patients with Child-Pugh A cirrhosis, although the difference did not reach statistical significance (HR 0.585, 95% CI 0.336-1.017, p = 0.0575). CONCLUSIONS: Oral BCAA supplementation is associated with reduced incidence of HCC in patients with cirrhosis and seems to prevent liver-related events in patients with Child-Pugh A cirrhosis.

Des-γ-carboxyprothrombin may be a promising biomarker to determine the therapeutic efficacy of sorafenib for hepatocellular carcinoma.

OBJECTIVE: The purpose of this study was to evaluate the role of des-γ-carboxyprothrombin (DCP) as a marker for the efficacy of sorafenib therapy for hepatocellular carcinoma (HCC). METHODS: Patients with advanced HCC treated with sorafenib were retrospectively evaluated, focusing on DCP levels and clinical characteristics. RESULTS: 50 patients with advanced HCC were treated with sorafenib alone. In 25 of these patients, the serum levels of DCP were evaluated twice (pretreatment and within 2 weeks after starting therapy). The time to progression was significantly longer in patients in whom the DCP level at 2 weeks after starting sorafenib was ≥2-fold higher than the pretreatment levels, as compared with patients without an increase in DCP (p = 0.0296). CONCLUSIONS: The serum level of DCP is a surrogate marker for tissue hypoxia and can be a predictive marker to assess the tumor response to sorafenib therapy.

Association of interleukin-28B and hepatitis C genotype 1 with a high viral load and response to pegylated interferon plus ribavirin therapy.

BACKGROUND: Pegylated interferon (PEG-IFN) plus ribavirin therapy is the current standard treatment for chronic hepatitis C (CHC) genotype 1 with high viral load. A common genetic variation near the IL28B gene has been found to affect the response to PEG-IFN plus ribavirin therapy for CHC. The aims of this study were to analyze the association between the rs8099917 genotype and treatment response in a cohort study of CHC. METHODS: This study evaluated clinical and laboratory parameters retrospectively in a cohort of 122 patients with chronic hepatitis C with genotype 1 and a high viral load who received PEG-IFN plus ribavirin therapy. We carried out univariate and multivariate statistical analyses of parameters and clinical responses. RESULTS: Sixty-three of 122 patients (51.6%) had sustained virological responses (SVRs). Patients with the rs8099917 genotype TT achieved significantly higher SVR rates (p < 0.01). Univariate analysis revealed that SVRs were associated with BMI, fibrosis, albumin, total cholesterol, PEG-IFN dose, ribavirin dose and the rs8099917 genotype. Multivariate analysis revealed that the rs8099917 genotype (odds ratio 7.434, 95% CI 2.278-24.257, p = 0.001) and total PEG-IFN dose (odds ratio 7.162, 95% CI 1.565-18.15, p = 0.007) were significant factors. CONCLUSIONS: The rs8099917 genotype and total PEG-IFN dose were associated with SVR in patients with hepatitis C virus genotype 1.

Stm1 is a vacuolar PQ-loop protein involved in the transport of basic amino acids in Schizosaccharomyces pombe.

The stm1+ (SPAC17C9.10) gene of Schizosaccharomyces pombe is closely related to genes encoding vacuolar PQ-loop proteins, Ypq1, Ypq2, and Ypq3, of Saccharomyces cerevisiae. When stm1+ fused with GFP was expressed in fission or budding yeast, Stm1-GFP localized at the vacuolar membrane. Isolated vacuolar membrane vesicles from S. cerevisiae cells overexpressing stm1+ exhibited stm1+-dependent arginine and lysine uptake activity. Exchange activity of arginine and histidine/arginine, as observed for Ypq2 of S. cerevisiae, was also detected in the vesicles expressing stm1+. The expression levels of stm1+ in S. pombe cells significantly affected the vacuolar contents of lysine, histidine, and arginine. These results suggest that Stm1 is a vacuolar PQ-loop protein involved in the transport of basic amino acids across the vacuolar membrane.

Radiofrequency ablation for hepatocellular carcinoma: assistant techniques for difficult cases.

PURPOSE: To confirm the safety and effectiveness of techniques to assist radiofrequency ablation (RFA) for difficult cases, we retrospectively evaluated successful treatment rates, early complications and local tumor progressions. PATIENTS AND METHODS: Between June 1999 and April 2009, a total of 341 patients with 535 nodules were treated as difficult cases. Artificial pleural effusion assisted ablation was performed on 64 patients with 82 nodules. Artificial ascites-assisted ablation was performed on 11 patients with 13 nodules. Cooling by endoscopic nasobiliary drainage (ENBD) tube-assisted ablation was performed on 6 patients with 8 nodules. When the tumors were not well visualized with conventional B-mode ultrasonography (US), contrast-enhanced US-assisted ablation with Levovist or Sonazoid or virtual CT sonography-assisted ablation was performed. Contrast-enhanced US-assisted ablation was performed on 139 patients with 224 nodules and virtual CT sonography-assisted ablation was performed on 121 patients with 209 nodules. RESULTS: In total, complete ablation was achieved in 514 of 535 (96%) nodules in difficult cases. For RFA with artificial pleural effusion, artificial ascites and ENBD, complete response was confirmed in all cases. For contrast-enhanced US- and CT sonography-assisted ablation, complete response was 95%. Early complications were recognized in 24 cases (4.5%). All cases recovered with no invasive treatment. Local tumor recurrence was investigated in 377 nodules of 245 patients, and 69 (18%) nodules were positive. Tumor recurrences in each assisted technique were 14.7% in artificial pleural effusion cases, 7% in artificial ascites, 12.5% in ENBD tube cases, 31% in virtual CT sonography, and 8.5% in contrast-enhanced US. CONCLUSION: Although local tumor progression needs to be carefully monitored, assisted techniques of RFA for difficult cases are well tolerated and expand the indications of RFA.

Hepatic arterial infusion chemotherapy using low-dose 5-fluorouracil and cisplatin for advanced hepatocellular carcinoma.

BACKGROUND: Although hepatic arterial infusion chemotherapy (HAIC) using low-dose 5-fluorouracil (5-FU) and cisplatin (low-dose FP) is commonly used for advanced hepatocellular carcinoma (HCC) with vascular invasion in Japan, few reports have investigated the efficacy and safety of this approach. We investigated the efficacy and toxicity of HAIC using low-dose FP for patients with advanced HCC as a phase II trial. METHODS: Low-dose FP consisted of a continuous arterial infusion of 5-FU (250-500 mg/day, 5 days/week, for the first 2 weeks) and cisplatin (10 mg/day, 5 days/week, for the first 2 weeks). Then, 5-FU (1,000 mg/body for 5 h) and cisplatin (10 mg/body) were administered once weekly. RESULTS: In these patients treated with low-dose FP, the response rate was 38.5%, the median time to progression was 4.1 months (95% CI 2.1-6.1 months) and the median survival time was 15.9 months (95% CI 9.8-22.0 months). The most frequent adverse events were myelosuppression such as neutropenia or thrombocytopenia. CONCLUSIONS: HAIC using low-dose FP is an effective treatment option for locally advanced HCC. However, it is not well tolerated hematologically because of potent pancytopenia and poor hepatic reserve. Therefore, this regimen should be performed carefully with regular monitoring of hematological function.

Usefulness of the post-vascular phase of contrast-enhanced ultrasonography with sonazoid in the evaluation of gross types of hepatocellular carcinoma.

OBJECTIVE: The purpose of this study was to assess the usefulness of post-vascular phase (PVP) images of contrast-enhanced ultrasonography (CE-US) in the evaluation of the gross types of hepatocellular carcinoma (HCC) that is closely related to the malignant potential of the tumor. METHODS: A total of 29 patients with 40 HCCs of <5 cm in diameter, who underwent hepatic resection, were enrolled. The gross type of the tumor was evaluated using real-time scanning during the PVP of CE-US with Sonazoid prior to surgery. The tumors were classified into three types based on the macroscopic classification of the Liver Cancer Study Group of Japan: single nodular (SN) type, single nodular with extranodular growth (SNEG) type, and confluent multinodular (CMN) type. The ability of CE-US to correctly depict the gross type of HCC was evaluated. RESULTS: 26 tumors were macroscopically diagnosed as the SN type, 11 tumors as the SNEG type, and 3 tumors as the CMN type. The sensitivity, specificity and accuracy of CE-US were 96, 80 and 90%, respectively. CONCLUSION: The PVP image of CE-US with Sonazoid is a useful tool in the evaluation of the gross type of HCC and is considered essential in deciding treatment strategy.

Changing trends in hepatitis C infection over the past 50 years in Japan.

In Japan, hepatocellular carcinoma (HCC) is the fourth leading cause of death in males and the fifth in females. Hepatitis C virus (HCV) is a major cause of HCC in Japan, with 70% of cases being HCV related. HCV genotype 1b, the most prevalent subtype in Japan, started to spread in the 1930s among injecting drug users (IDUs) during and after World War II or through medical procedures such as blood transfusion and use of contaminated syringes. The prevalence of HCV infection is much lower in the current younger generation compared with that in the older generation, particularly those aged >55 years (0.1-0.2% vs. > or = 2%). Therefore, the total number of patients with HCV infection is estimated to decrease, even though sporadic HCV transmission is mainly seen among young IDUs. Of note, HCV genotype 2 seems to be spreading among IDUs, but the response to antiviral therapy in these patients seems to be better than that in older patients, irrespective of the genotype. Although the number of patients who die because of HCC has steadily increased over the last 50 years, the incidence of HCC is now decreasing, mainly because of the decreased prevalence of HCV-related HCC.

Prolonged PEG-IFN and RBV is effective in patients with HCV genotype 1 and high viral load who achieved virological response later than 24 weeks.

OBJECTIVE: The extension of treatment duration has been proposed in late virological responders with hepatitis C virus (HCV) genotype 1 and high viral load. However, the effectiveness of extended treatment in patients whose serum HCV RNA become undetectable later than 24 weeks of treatment (ultra-late virological responder; ULVR) has not yet been determined. METHODS: A total of 130 patients infected with HCV genotype 1 and who had high viral load were treated with pegylated interferon (PEG-IFN) and ribavirin (RBV) combination therapy. We retrospectively analyzed 10 ULVR who received extended combination treatment beyond 48 weeks. RESULTS: The duration of the combination treatment for ULVR ranged between 59 and 119 weeks, and the mean duration was 80 weeks. Although the majority of ULVR were older female patients (> or = 60 years) with factors related to poor therapeutic response, 8 patients (80%) achieved sustained virological response (SVR). The SVR rate correlated well with the duration of the treatment. Five ULVR achieved SVR when treatment was continued until serum HCV RNA remained undetectable for longer than 48 weeks. CONCLUSION: The extended duration of PEG-IFN and RBV combination treatment is a possible strategy to improve treatment response in HCV genotype 1 infection, even for ULVR.

PEG-IFNalpha/RBV combination therapy for chronic hepatitis C patients increases serum ferritin level while it improves sustained viral response rate.

OBJECTIVES: We investigated the significance of serum ferritin levels in pegylated interferon (PEG-IFN) and ribavirin (RBV) combination therapy for chronic hepatitis C (CHC) and examined its correlation with serum alanine aminotransferase (ALT) levels during therapy and response to the therapy. METHODS: A total of 175 patients with CHC received the combination therapy. Correlations between serum ferritin levels and serum ALT levels at 12 and 24 weeks of therapy were examined. Differences in serum ferritin levels during therapy between patients with sustained viral response (SVR) and non-SVR were also examined. RESULTS: Only 24 (13.7%) and 20 (11.4%) patients showed elevated serum ALT levels (> or = 70 IU/l) at 12 and 24 weeks of therapy, respectively. There was no correlation between serum ferritin levels and ALT levels. Ninety-five (54.3%) of 175 patients achieved SVR. Serum ferritin levels increased dramatically in both SVR and non-SVR groups after starting the therapy and were significantly higher in the SVR group throughout the therapy. CONCLUSIONS: Serum ferritin level increases during PEG-IFN and RBV combination therapy; however, it did not correlate with either serum ALT level or the total dose of RBV. Higher serum ferritin levels during combination therapy appear to be associated with favorable therapeutic response.

Imaging of hepatocellular carcinoma: qualitative and quantitative analysis of postvascular phase contrast-enhanced ultrasonography with sonazoid. Comparison with superparamagnetic iron oxide magnetic resonance images.

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, chi(2) 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, chi(2) 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.

PIVKA-II is the best prognostic predictor in patients with hepatocellular carcinoma after radiofrequency ablation therapy.

OBJECTIVE: This study was undertaken to assess the prognostic predictor in patients with hepatocellular carcinoma (HCC) after radiofrequency ablation (RFA). METHODS: This study retrospectively evaluated clinical outcomes in a cohort of 179 Child-Pugh stage A cirrhotic patients who received curative RFA for naive HCC within Milan criteria. The median follow-up period was 40.5 months. RESULTS: The cumulative survival rate was significantly lower in patients with prothrombin induced by vitamin K absence or antagonist II (PIVKA-II) > or =100 mAU/ml compared with PIVKA-II <100 mAU/ml (58.0 vs. 84.0% at 5 years; p < 0.001). The cumulative recurrence-free survival rates were significantly lower in patients with PIVKA-II > or =100 mAU/ml compared with PIVKA-II <100 mAU/ml (12.1 vs. 16.9% at 5 years; p < 0.032). The cumulative rate of maintaining period within Milan criteria was significantly lower in patients with PIVKA-II > or =100 mAU/ml compared with PIVKA-II <100 mAU/ml (34.1 vs. 55.6% at 5 years; p < 0.001). Cox regression analysis showed that low serum albumin (<3.5 g/dl; p = 0.002, RR 3.75, CI 1.64-8.56), a high level of PIVKA-II (> or =100 mAU/ml; p = 0.04, RR 3.15, CI 1.45-6.87), and multiple nodules (p = 0.021, RR 2.61, CI 1.15-5.91) were independently significant mortality risk factors. CONCLUSION: In patients with Child-Pugh stage A HCC, the PIVKA-II level is the best prognostic predictor after curative RFA.

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; chi(2) 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.

Combination therapy with S-1 and pegylated interferon alpha for advanced hepatocellular carcinoma.

PURPOSE: There are currently no effective treatments for patients with advanced hepatocellular carcinoma (HCC) with vascular invasion or extrahepatic metastases. We evaluated the efficacy and safety of combination therapy with S-1 and pegylated interferon (PEG-IFN)-alpha for advanced HCC. METHODS: A total of 22 patients received combination therapy with S-1 and PEG-IFN. One cycle of the combination therapy consists of oral S-1 (80 mg/m(2)) administration and subcutaneous PEG-IFN injection (PEG-IFN-alpha-2a 90 microg weekly or PEG-IFN-alpha-2b 50 microg weekly) for 4 weeks with 1- to 2-week intervals. RESULTS: One patient was evaluated as complete response, 6 as partial response, 8 as stable disease, and 6 as progressive disease. One patient was not evaluable because therapy had to be discontinued as a result of jaundice. The median survival time was 15.3 months (95% CI: 4.4-26.2 months). The 1- and 2-year survival rates were 54.9 and 36.6%, respectively. The overall response rate was 31.8% and the disease control rate was 68.2%. Grade 3 neutropenia (18.2%), leukopenia (9.1%), anemia (9.1%), and thrombocytopenia (18.2%) were observed. Grade 4 toxicities were not observed. CONCLUSION: Combination therapy with S-1 and PEG-IFN is effective and feasible, and is therefore a promising regimen for advanced HCC.

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.

Initial treatment response is essential to improve survival in patients with hepatocellular carcinoma who underwent curative radiofrequency ablation therapy.

OBJECTIVE: This study was undertaken to assess the outcome of potentially curative radiofrequency ablation (RFA) therapy for early-stage hepatocellular carcinoma (HCC) in patients with Child-Pugh stage A cirrhosis. METHODS: This study retrospectively evaluated clinical outcomes in a cohort of 171 Child-Pugh stage A cirrhotic patients who received RFA for naïve HCC within the Milan criteria. The median follow-up period was 36.7 months. RESULTS: Cumulative survival rates estimated by the Kaplan-Meier method for all patients were 98.8, 91.1 and 76.8% at 1, 3 and 5 years, respectively. Cumulative probabilities of local tumor recurrence at 1, 2 and 3 years were 9.0, 14.1 and 17.7%, respectively. Cumulative survival rates in patients without local tumor recurrence were 96.6, 94.6 and 84.4% at 1, 3 and 5 years, respectively, compared with patients with local tumor recurrence (96.6, 74.8 and 42.1% at 1, 3 and 5 years, respectively; p = 0.0002). Cox regression analysis showed that low serum albumin (p = 0.009, RR 3.04, CI 1.32-6.98), high range of PIVKA-II (prothrombin induced by vitamin K absence or agonist II) (p = 0.025, RR 2.57, CI 1.13-5.89), with multiple (less than 3) nodules (p = 0.021, RR 2.61, CI 1.15-5.91), and with local tumor recurrence (p = 0.004, RR 3.62, CI 1.51-8.69) were significant risk factors for death. CONCLUSION: Initial complete response of curative RFA therapy in patients with Child-Pugh stage A cirrhosis and early-stage HCC is associated with improved survival. Therefore, clinicians should aim to achieve complete ablation of all detectable HCC nodules with adequate safety margins.

Percutaneous radiofrequency ablation of sonographically unidentifiable liver tumors. Feasibility and usefulness of a novel guiding technique with an integrated system of computed tomography and sonographic images.

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.

Baseline noise and measurement uncertainty in liquid chromatography.

The stochastic properties of baseline noise in HPLC systems with a UV photo-diode array, photo-multiplier and gamma-ray detector were examined by dividing the noise into auto-correlated random process (Markov process) and an independent process (white noise). The present work focused on the effect of the stochastic noise properties on a theoretical estimation of the standard deviation (SD) of area measurements in instrumental analyses. An estimation theory, called FUMI theory (Function of Mutual Information), was taken as an example. A computer simulation of noise was also used. It was shown that the reliability (confidence intervals) of theoretical SD estimates mainly depends on the following factors: the ratio of the white noise and Markov process occurring in the baselines; the number of data points used for the estimation; the width of a target peak for which the SD is estimated.