Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Satoshi Kitai is active.

Publication


Featured researches published by Satoshi Kitai.


Intervirology | 2008

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

Kinuyo Hatanaka; Masatoshi Kudo; Yasunori Minami; Taisuke Ueda; Chie Tatsumi; Satoshi Kitai; Shunsuke Takahashi; Tatsuo Inoue; Satoru Hagiwara; Hobyung Chung; Kazuomi Ueshima; Kiyoshi Maekawa

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.


Intervirology | 2008

Noninvasive Evaluation of Hepatic Fibrosis Using Serum Fibrotic Markers, Transient Elastography (FibroScan) and Real-Time Tissue Elastography

Chie Tatsumi; Masatoshi Kudo; Kazuomi Ueshima; Satoshi Kitai; Shunsuke Takahashi; Tatsuo Inoue; Yasunori Minami; Hobyung Chung; Kiyoshi Maekawa; Kenji Fujimoto; Tonomura Akiko; Mitake Takeshi

Objective: The aim of this study was to investigate the accuracy of noninvasive tests, e.g. serum fibrotic markers, transient elastography and real-time tissue elastography, in the diagnosis of hepatic fibrosis, and to determine whether they can replace liver biopsy. Methods: 119 patients with chronic liver disease were included in this study. Serum fibrotic markers including hyaluronic acid, type IV collagen, type IV collagen 7S domain and type III procollagen-N-peptide were measured. Aspartate aminotransferase (AST) and platelet counts were also measured to calculate the AST to platelet ratio index (APRI). Liver stiffness was measured using FibroScan and real-time tissue elastography. Results: The fibrotic stage, determined by histopathological diagnosis of a liver biopsy sample, did not correlate as well with serum fibrotic markers although it was useful to diagnose liver cirrhosis. However, the stage of hepatic fibrosis correlated well with liver stiffness measured by FibroScan. FibroScan was also a much better predictor of liver cirrhosis than APRI. Furthermore, the levels of liver strain measured by real-time tissue elastography correlated well with liver stiffness (p < 0.05). Conclusion: Serum fibrotic markers and FibroScan are useful for distinguishing liver cirrhosis (F4) from chronic hepatitis (F1–F3). In addition, real-time tissue elastography is a novel and promising method to determine the stage of hepatic fibrosis.


American Journal of Roentgenology | 2008

Radiofrequency ablation of hepatocellular carcinoma: value of virtual CT sonography with magnetic navigation.

Yasunori Minami; Hobyung Chung; Masatoshi Kudo; Satoshi Kitai; Shunsuke Takahashi; Tatsuo Inoue; K. Ueshima; Hitoshi Shiozaki

OBJECTIVE Virtual CT sonography with magnetic navigation yields cross-sectional images of CT volume data that correspond to the angle of the transducer in the magnetic field in real time. The purpose of this study was to evaluate the efficiency and feasibility of virtual CT sonography for radiofrequency ablation of hypervascular hepatocellular carcinoma poorly defined on B-mode sonography. MATERIALS AND METHODS One hundred one patients enrolled in the study were separated into two groups. Fifty-one patients with 65 hepatocellular carcinomas underwent prospective virtual CT sonography as guidance for radiofrequency ablation. Fifty patients with 63 hepatocellular carcinomas managed with B-mode sonographic guidance were retrospectively selected under the same conditions as the virtual CT sonography group to act as a historical control group. RESULTS In the virtual CT sonography group, technically successful ablation was achieved in a single session in 92% (47/51) of the patients and in two sessions in 8% (4/51). In the B-mode sonography group, technical success was achieved in a single session in 72% (36/50) of the patients, in two sessions in 24% (12/50), and in three sessions in 4% (2/50). Treatment analysis showed that the technical success rate after a single treatment session was significantly (p = 0.017) higher for the virtual CT sonography group. The number of treatment sessions was significantly (p = 0.021) lower for the virtual CT sonography group (mean, 1.1 +/- 0.1 vs 1.3 +/- 0.3 sessions). CONCLUSION Virtual CT sonographically assisted radiofrequency ablation is an efficient treatment of patients with hepatocellular carcinoma that is poorly defined on B-mode sonography.


Oncology | 2007

Initial Treatment Response Is Essential to Improve Survival in Patients with Hepatocellular Carcinoma Who Underwent Curative Radiofrequency Ablation Therapy

Shunsuke Takahashi; Masatoshi Kudo; Hobyung Chung; Tatsuo Inoue; Emi Ishikawa; Satoshi Kitai; Chie Tatsumi; Taisuke Ueda; Yasunori Minami; Kazuomi Ueshima; Seiji Haji

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.


Oncology | 2007

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

Masatoshi Kudo; Yasuhiro Sakaguchi; Hobyung Chung; Kinuyo Hatanaka; Satoru Hagiwara; Emi Ishikawa; Shunsuke Takahashi; Satoshi Kitai; Tatsuo Inoue; Yasunori Minami; Kazuomi Ueshima

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.


Intervirology | 2010

Non-Invasive Evaluation of Hepatic Fibrosis for Type C Chronic Hepatitis

Chie Tatsumi; Masatoshi Kudo; Kazuomi Ueshima; Satoshi Kitai; Emi Ishikawa; Norihisa Yada; Satoru Hagiwara; Tatsuo Inoue; Yasunori Minami; Hobyung Chung; Kiyoshi Maekawa; Kenji Fujimoto; Michio Kato; Akiko Tonomura; Tsuyoshi Mitake; Tsuyoshi Shiina

Objective: The aim of this study was to investigate liver fibrosis using non-invasive Real-time Tissue Elastography® (RTE) and transient elastography (FibroScan®) methods. Methods: RTE, FibroScan and percutaneous liver biopsy were all performed on patients with chronic liver disease, particularly hepatitis C, to investigate liver fibrosis. Results: FibroScan and RTE were compared for fibrous liver staging (F stage), which was pathologically classified using liver biopsy. In FibroScan, significant differences were observed between F1/F3 and F2/F4, but no such differences were observed between F1/F2, F2/F3 and F3/F4. In RTE, significant differences were observed between F1/F2, F2/F3 and F2/F4. But for F3/F4, no significant differences were observed. Conclusion: FibroScan and RTE correlated well with F staging of the liver. In particular RTE was more successful than FibroScan in diagnosing the degree of liver fibrosis.


Oncology | 2010

Hepatic Arterial Infusion Chemotherapy Using Low-Dose 5-Fluorouracil and Cisplatin for Advanced Hepatocellular Carcinoma

Kazuomi Ueshima; Masatoshi Kudo; Masahiro Takita; Tomoyuki Nagai; Chie Tatsumi; Taisuke Ueda; Satoshi Kitai; Emi Ishikawa; Norihisa Yada; Tatsuo Inoue; Satoru Hagiwara; Yasunori Minami; Hobyung Chung

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.


Oncology | 2008

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

Yu Xia; Masatoshi Kudo; Yasunori Minami; Kinuyo Hatanaka; Kazuomi Ueshima; Hobyung Chung; Satoru Hagiwara; Tatsuo Inoue; Emi Ishikawa; Satoshi Kitai; Shunsuke Takahashi; Chie Tatsumi; Taisuke Ueda; Sosuke Hayaishi; Kiyoshi Maekawa

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.


Liver cancer | 2015

Effectiveness of Sorafenib in Patients with Transcatheter Arterial Chemoembolization (TACE) Refractory and Intermediate-Stage Hepatocellular Carcinoma

Tadaaki Arizumi; Kazuomi Ueshima; Tomohiro Minami; Masashi Kono; Hirokazu Chishina; Masahiro Takita; Satoshi Kitai; Tatsuo Inoue; Norihisa Yada; Satoru Hagiwara; Yasunori Minami; Toshiharu Sakurai; Naoshi Nishida; Masatoshi Kudo

Background and Aims: Patients with intermediate-stage hepatocellular carcinoma (HCC) refractory to transcatheter arterial chemoembolization (TACE) are considered to be candidates for sorafenib. The aim of this study was to evaluate the superiority of conversion of treatment to sorafenib on overall survival (OS) for cases refractory to TACE. Methods: This was a retrospective cohort study carried out on 497 patients with HCC who were treated with TACE therapy at our hospital between January 2008 and December 2013. Fifty-six patients were diagnosed as refractory to TACE during their clinical course and they were divided into two cohorts, (1) those who switched from TACE to sorafenib and (2) those who continued TACE. The overall survival (OS) after the time of being refractory to TACE was evaluated between the two groups. Results: After refractoriness to TACE therapy was confirmed, 24 patients continued with TACE (TACE-group) and 32 patients underwent treatment conversion to sorafenib (sorafenib-group). The median OS was 24.7 months in the sorafenib-group and 13.6 months in the TACE-group (p=0.002). Conclusions: Conversion to sorafenib significantly improves the OS in patients refractory to TACE therapy with intermediate-stage HCC. Administration of sorafenib is therefore recommended in such circumstances of TACE treatment failure.


Liver International | 2010

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

Yasunori Minami; Masatoshi Kudo; Kinuyo Hatanaka; Satoshi Kitai; Tatsuo Inoue; Satoru Hagiwara; Hobyung Chung; Kazuomi Ueshima

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.

Collaboration


Dive into the Satoshi Kitai's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge