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Dive into the research topics where Hirohiko Nagata is active.

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Featured researches published by Hirohiko Nagata.


International Journal of Clinical Oncology | 2007

Brachytherapy with permanent seed implantation

Shiro Saito; Hirohiko Nagata; Michio Kosugi; Kazuhito Toya; Atsunori Yorozu

Permanent interstitial brachytherapy with iodine-125 (I-125) or palladium 103 (Pd-103) seeds is a common treatment option in the United States, and numerous articles on outcomes after long-term follow up have been published. With the treatments apparent high efficacy and low morbidity, permanent seed implantation has become the most frequently employed procedure for localized prostate cancer and has replaced radical prostatectomy. Even taking into account the good features of the treatment, the performance of permanent seed implantation in Japan had not been allowed because of the countrys strict laws on radiation safety. However, after a long period of discussion between Japanese medical associations and the government, permanent interstitial brachytherapy with I-125 was finally approved in Japan in July 2003. The guidelines for this treatment include several restrictions that should be followed by each institution that is to perform the treatment. Over 70 institutes around the country had started the treatment before the end of June 2007. With high expectations for this new radiation therapy, which may be effective, and less invasive than previous treatments and with a low incidence of treatment morbidity, brachytherapy for prostate cancer will become more common in Japan. For the purpose of improving the quality of seed implantation, which may lead to better clinical outcomes and radiation safety, medical conferences and technical training courses have been carried out regularly, and multi-institutional clinical studies have also been carried out countrywide.


BJUI | 2009

Prostate-specific antigen ‘bounce’ after permanent 125I-implant brachytherapy in Japanese men: a multi-institutional pooled analysis

Takefumi Satoh; Hiromichi Ishiyama; Kazumasa Matsumoto; Hideyasu Tsumura; Masashi Kitano; Kazushige Hayakawa; Shin Ebara; Yasutomo Nasu; Hiromi Kumon; Susumu Kanazawa; Kenta Miki; Shin Egawa; Manabu Aoki; Kazuhito Toya; Atsushi Yorozu; Hirohiko Nagata; Shiro Saito; Shiro Baba

To examine the incidence, timing, and magnitude of the prostate‐specific antigen (PSA) level ‘bounce’ after permanent prostate brachytherapy (BT) and correlate the PSA bounce with clinical and dosimetric factors in Japanese patients with prostate cancer.


World Journal of Urology | 1999

Retroperitoneoscopic adrenalectomy by a lumbodorsal approach: clinical experience with solo surgery

Shiro Baba; Keiichi Ito; Hitoshi Yanaihara; Hirohiko Nagata; Masaru Murai; Masatsugu Iwamura

Abstract Laparoscopic adrenalectomy by transperitoneal approaches necessitates the retraction of intraperitoneal organs and, hence, the creation of extra ports for retractors and assistants. The feasibility of retroperitoneoscopic adrenalectomy by a lumbodorsal approach was assessed in 26 patients with adrenal tumors. In six patients the procedure was carried out as solo surgery using the ABSOP robot camera holder, and the performance was compared with that reported for the most recent series of six cases operated upon with one human assistant. The procedures were successful in 25 patients. One patient had to be converted due to tension pneumothorax caused by diaphragmatic injury. The mean blood loss was 43.5 ± 67.5 ml, and the procedure time averaged 144 ± 33 min. We required an average of only 3.1 trocars to accomplish solo surgery in 5 of 6 patients (83%). The number of lens smearings decreased to one-fourth of that observed by a human assistant.


Radiation Oncology | 2011

Incidence of seed migration to the chest, abdomen, and pelvis after transperineal interstitial prostate brachytherapy with loose 125 I seeds

Akitomo Sugawara; Jun Nakashima; Etsuo Kunieda; Hirohiko Nagata; Ryuichi Mizuno; Satoshi Seki; Yutaka Shiraishi; Ryuichi Kouta; Mototsugu Oya; Naoyuki Shigematsu

BackgroundThe aim was to determine the incidence of seed migration not only to the chest, but also to the abdomen and pelvis after transperineal interstitial prostate brachytherapy with loose 125I seeds.MethodsWe reviewed the records of 267 patients who underwent prostate brachytherapy with loose 125I seeds. After seed implantation, orthogonal chest radiographs, an abdominal radiograph, and a pelvic radiograph were undertaken routinely to document the occurrence and sites of seed migration. The incidence of seed migration to the chest, abdomen, and pelvis was calculated. All patients who had seed migration to the abdomen and pelvis subsequently underwent a computed tomography scan to identify the exact location of the migrated seeds. Postimplant dosimetric analysis was undertaken, and dosimetric results were compared between patients with and without seed migration.ResultsA total of 19,236 seeds were implanted in 267 patients. Overall, 91 of 19,236 (0.47%) seeds migrated in 66 of 267 (24.7%) patients. Sixty-nine (0.36%) seeds migrated to the chest in 54 (20.2%) patients. Seven (0.036%) seeds migrated to the abdomen in six (2.2%) patients. Fifteen (0.078%) seeds migrated to the pelvis in 15 (5.6%) patients. Seed migration occurred predominantly within two weeks after seed implantation. None of the 66 patients had symptoms related to the migrated seeds. Postimplant prostate D90 was not significantly different between patients with and without seed migration.ConclusionWe showed the incidence of seed migration to the chest, abdomen and pelvis. Seed migration did not have a significant effect on postimplant prostate D90.


British Journal of Cancer | 2013

The prognostic significance of vasohibin-1 expression in patients with prostate cancer.

Takashi Kosaka; Yoshitsugu Miyazaki; Akira Miyajima; Shuji Mikami; Yukiko K. Hayashi; Nobuyuki Tanaka; Hirohiko Nagata; Eiji Kikuchi; Keiichi Nakagawa; Yasunori Okada; Yoshinori Sato; Mototsugu Oya

Background:We recently isolated vasohibin-1 (VASH1), a novel angiogenic molecule that is specifically expressed in activated vascular endothelial cells (ECs), and the status of VASH1 expression has been documented in various cancer angiogenesis. The aim of this study was to assess the prognostic value of VASH1 expression in prostate cancer (PCa).Methods:In this study, we retrospectively analysed the clinical records and evaluated the VASH1 expression of tumour microvessels in 167 patients with PCa who underwent radical prostatectomy. We immunohistochemically examined the microvessels positive for anti-CD34 as microvessel density (MVD) and the microvessels with activated ECs positive for VASH1 density.Results:We found that the VASH1 expression was restricted to ECs in the tumour stroma. VASH1 density was significantly associated with pathological T stage, Gleason score and MVD. The 5-year PSA recurrence-free survival rate was 58.8% in patients with higher VASH1 density (≧12 per mm2) and 89.1% in patients with lower VASH1 density (<12 per mm2), respectively (P<0.001). Microvessel density was not an independent predictor of PSA recurrence. Multivariate analysis revealed that high VASH1 density was an independent prognostic indicator of PSA recurrence (P=0.007, HR=2.950).Conclusion:VASH1 density represents a clinically relevant predictor of patient prognosis and can be a new biomarker that would provide additional prognostic information in PCa.


Japanese Journal of Clinical Oncology | 2012

Patterns of Interstitial Lung Disease During Everolimus Treatment in Patients with Metastatic Renal Cell Carcinoma

Ryuichi Mizuno; Koichiro Asano; Shuji Mikami; Hirohiko Nagata; Gou Kaneko; Mototsugu Oya

OBJECTIVE To elucidate the patterns of interstitial lung disease during everolimus treatment in patients with metastatic renal cell carcinoma, we reviewed seven cases of everolimus-induced interstitial lung disease. METHODS Seven patients with metastatic renal cell carcinoma, which continued to progress despite treatment with sunitinib or sorafenib, developed interstitial lung disease after treatment with everolimus. RESULTS Chest X-ray demonstrated diffuse infiltrates in lung fields, and chest computed tomography showed bilateral reticular and ground-glass opacities. Serum levels of lactate dehydrogenase (7/7), C-reactive protein (6/7), pulmonary surfactant associated protein D (1/7) and Krebs von den Lungen 6 (5/7) were elevated. The bronchoalveolar lavage fluid obtained from four patients with Grade 3 interstitial lung disease showed lymphocytosis. The transbronchial lung biopsy specimens showed interstitial lymphocytic infiltration and septal thickening of alveolar walls. In two cases with mild interstitial lung disease, the everolimus therapy was successfully continued. In four cases with Grade 3 interstitial lung disease, the drug was discontinued and steroid therapy was initiated. Pulmonary symptoms and radiological abnormalities resolved within 2 months. CONCLUSIONS Serum Krebs von den Lungen 6 was elevated compared with baseline in all cases with interstitial lung disease. Some patients who developed mild interstitial lung disease during everolimus treatment could continue to receive the treatment. Even when severe interstitial lung disease developed, withdrawal of the drug and short-term use of high-dose steroids resulted in rapid recovery. Prompt recognition of interstitial lung disease exacerbation as well as exclusion of progressive disease or infection is of primary importance.


Japanese Journal of Clinical Oncology | 2010

Docetaxel in Combination with Prednisolone for Hormone Refractory Prostate Cancer

Hiroki Ide; Eiji Kikuchi; Hidaka Kono; Hirohiko Nagata; Akira Miyajima; Ken Nakagawa; Takashi Ohigashi; Jun Nakashima; Mototsugu Oya

OBJECTIVE The objective of this study was to evaluate the efficacy and toxicity of docetaxel in combination with prednisolone in Japanese patients with hormone refractory prostate cancer. METHODS Twenty patients with hormone refractory prostate cancer (HRPC) were administered a treatment regimen consisting of docetaxel 75 mg/m(2) once every 3 or 4 weeks and prednisolone 5 mg twice daily at our institution between 2006 and 2008. RESULTS The patients received a median of 5.5 cycles of treatment (range, 2-12 cycles). Nine of the 20 patients (45%) had a >or=50% decrease in serum prostate-specific antigen (PSA). The median duration of response was 4 months (range, 1-11 months). The number of cycles performed, the presence of bone metastasis and the extent of disease had statistically significant associations with the response. Three patients had a transient PSA rise among the patients who ultimately had a response. Grade 3/4 leukopenia and neutropenia occurred in 80.0% and 85.0% of the patients, respectively. Interstitial pneumonia occurred in only one patient; however, the patient recovered. Finally, no treatment-related deaths were seen during the observation period. CONCLUSIONS The combination of docetaxel 75 mg/m(2) every 3 weeks and prednisolone 10 mg daily was effective and well tolerated in Japanese patients with HRPC. The results of this study suggest that a decision concerning discontinuation of this treatment should be carefully considered because a transient PSA rise was observed. Although interstitial pneumonia was rare, the potential risk of its development should be taken into consideration.


The Journal of Urology | 2012

A prospective longitudinal survey of erectile dysfunction in patients with localized prostate cancer treated with permanent prostate brachytherapy.

Masashi Matsushima; Eiji Kikuchi; Takahiro Maeda; Jun Nakashima; Akitomo Sugawara; Toshiyuki Ando; Ryuichi Mizuno; Hirohiko Nagata; Akira Miyajima; Naoyuki Shigematsu; Mototsugu Oya

PURPOSE Few studies have evaluated changes in erectile function with time before and after prostate brachytherapy using the International Index of Erectile Function-15, a sensitive, validated tool for assessing male sexual dysfunction. In this prospective study we evaluated the natural history of erectile function after prostate brachytherapy without supplemental therapy (external beam radiotherapy, phosphodiesterase-5 inhibitors or androgen deprivation therapy) using the International Index of Erectile Function-15. MATERIALS AND METHODS We identified 119 patients who were followed at least 12 months after prostate brachytherapy between 2004 and 2010. Sexual and erectile function status were assessed before brachytherapy (baseline), and 3, 6, 12, 18, 24 and 36 months postoperatively using the International Index of Erectile Function-15. RESULTS Mean total International Index of Erectile Function-15 score, and scores on the erectile function, orgasmic function, sexual desire and intercourse satisfaction domains 3 months after brachytherapy were significantly lower than at baseline (p <0.05). They remained lower until 36 months after prostate brachytherapy. Erectile function was maintained 12 months after brachytherapy in 16 of the 48 men (33.3%) with a baseline erectile function domain score of 11 or greater. There was no significant difference in clinical features except the age of patients who maintained the erectile function domain score and their counterparts 12 months after brachytherapy. Multivariate analysis revealed that age 70 years or greater was the only predictive factor for deteriorating erectile function after brachytherapy (p = 0.035). CONCLUSIONS Findings indicate a global decrease in all domains of the International Index of Erectile Function-15 score 12 months after prostate brachytherapy. Also, patient age may influence the preservation of brachytherapy related potency.


Japanese Journal of Clinical Oncology | 2010

Contrast-enhanced Ultrasonography of the Prostate with Sonazoid

Kazuhiro Matsumoto; Ken Nakagawa; Akinori Hashiguchi; Hidaka Kono; Eiji Kikuchi; Hirohiko Nagata; Akira Miyajima; Mototsugu Oya

OBJECTIVE The diagnosis of prostate cancer is based on the results of ultrasonography-guided needle biopsy of the prostate, but cancer foci are often not visible in conventional transrectal ultrasonography. Sonazoid is a new microbubble contrast agent. The purpose of our study was to compare areas of contrast material enhancement in the prostate at ultrasonography with whole-mount radical prostatectomy specimens to determine if the use of Sonazoid improves the detection rate of prostate cancer. METHODS Fifty patients with biopsy-proven cancer of the prostate who were scheduled to undergo radical prostatectomy were recruited for this study. The day before the operation, each patient was evaluated with ultrasonography at baseline and again during intravenous infusion of Sonazoid. A map of ultrasonography findings was created prospectively at the time of imaging. Following radical prostatectomy, independent mapping of the pathologic results was performed and the maps were compared. RESULTS Ultrasonography evaluation at baseline demonstrated that at least one focus of cancer was identified in 20 of the 50 subjects (40.0%). Meanwhile at least one cancer focus was enhanced in 31 of the 50 patients (62.0%) when Sonazoid was used. The combination of baseline grayscale imaging and contrast-enhanced imaging allowed identification of at least one focus of cancer in 40 patients (80.0%). Contrast-enhanced ultrasonography can improve sensitivity, especially for the detection of large cancer, peripheral zone cancer and highly malignant cancer. CONCLUSIONS Our study has demonstrated significantly improved detection of prostate cancer with the combination of baseline grayscale imaging and contrast-enhanced imaging compared with conventional ultrasonography techniques only, and this technique may be applicable to targeted biopsy.


International Journal of Clinical Oncology | 2009

Prediction of PSA bounce after permanent prostate brachytherapy for localized prostate cancer.

Kunimitsu Kanai; Jun Nakashima; Akitomo Sugawara; Naoyuki Shigematsu; Hirohiko Nagata; Eiji Kikuchi; Akira Miyajima; Ken Nakagawa; Atsushi Kubo; Mototsugu Oya

BackgroundWe aimed to calculate the frequency and features of the development of a prostate-specific antigen (PSA) bounce after prostate brachytherapy alone, to correlate the bounce with clinical and dosimetric factors and to identify factors that predict PSA bounce.MethodsPSA bounce was evaluated in 86 patients with T1-T2 prostate cancer who underwent radioactive seed implantation using iodine-125 (I-125) without hormonal therapy or external-beam radiation therapy (EBRT) from September 2004 to December 2007. A PSA bounce was defined as a rise of at least 0.4 ng/ml greater than a previous PSA level with a subsequent decline equal to, or less than, the initial nadir.ResultsCalculated by the Kaplan-Meier method, the incidence of PSA bounce at a 2-year follow-up was 26%. Median time to the PSA bounce was 15 months. Univariate analysis demonstrated that age, dose received by 90% of the prostate gland (D90), volume of gland receiving 100% of the prescribed dose (V100), and V150 were significantly associated with the PSA bounce, while pretreatment PSA level, Gleason score, pretreatment prostate volume, clinical T stage, and V200 were not. In multivariate analysis, age 67 years or less and D90 more than 180 Gy were identified as independent factors for predicting the PSA bounce (P < 0.05).ConclusionPSA bounce is not a rare phenomenon after prostate brachytherapy. It is more common in younger patients and patients receiving higher doses of radiation.

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