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Dive into the research topics where Seiji Kubota is active.

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Featured researches published by Seiji Kubota.


European Radiology | 2008

Contrast-enhanced MR imaging of the brain using T1-weighted FLAIR with BLADE compared with a conventional spin-echo sequence.

Shinji Naganawa; Hiroko Satake; Shingo Iwano; Hisashi Kawai; Seiji Kubota; Tomohiro Komada; Minako Kawamura; Yasuo Sakurai; Hiroshi Fukatsu

The BLADE and PROPELLER (periodically rotated overlapping parallel lines with enhanced reconstruction) techniques have been proposed to reduce the effect of head motion. Preliminary results have shown that BLADE also reduces pulsation artifacts from venous sinuses. The purpose of this study was to compare T1-weighted FLAIR acquired with BLADE (T1W-FLAIR BLADE) and T1-weighted spin-echo (T1W-SE) for the detection of contrast enhancement in a phantom and in patients with suspected brain lesions and to compare the degree of flow-related artifacts in the patients. A phantom filled with diluted Gd-DTPA was scanned in addition to 27 patients. In the phantom study, the peak contrast-to-noise ratio of T1W-FLAIR BLADE was larger than that of T1W-SE, and the position of the peak was shifted to a lower concentration. In patients, the degree of flow-related artifacts was significantly higher in T1W-SE. Among the 27 patients, 9 had metastatic tumor, and 18 did not. On a patient-by-patient basis, the sensitivity and specificity for the detection of metastatic lesions on axial T1W-SE were 100% and 55.6% respectively, while on axial T1W-FLAIR BLADE they were 100% and 100%. T1W-FLAIR BLADE seems to be capable of replacing T1W-SE, at least for axial post-contrast imaging to detect brain metastases.


Head & Neck Oncology | 2010

Radiotherapy with or without chemotherapy for patients with T1-T2 glottic carcinoma: retrospective analysis

Naoki Hirasawa; Yoshiyuki Itoh; Shunichi Ishihara; Seiji Kubota; Junji Itoh; Yasushi Fujimoto; Tsutomu Nakashima; Shinji Naganawa

BackgroundTo assess the results for local control (LC) and survival in patients with early-stage glottic cancer (GC) who were treated by radiotherapy (RT) with or without chemotherapy.MethodsFifty-eight patients with T1-T2 squamous cell carcinoma of the glottis who were treated between 2001 and 2006 were analyzed retrospectively. Potential prognostic factors for LC were evaluated by univariate analysis.ResultsThe 5-year LC rate in all patients was 84.3%. The overall 5-year LC rates for patients with T1a, Tb, and T2 GC were 85.9%, 83%, and 85%, respectively. Of the 58 patients, eight developed recurrent disease at the primary site, and one had lymph node recurrences on the neck. In the final analysis, the total laryngectomy-free survival rate was 93% at five years, and the ultimate LC rates for T1a, Tb, and T2 were 100%, 90.9%, and 95.2%, respectively. In a univariate analysis of 55 patients, there was no statistical significance between the LC rate for RT alone and that for chemoradiation. Only two patients died of laryngeal carcinoma, and one died of intercurrent disease. Fifty-five patients were living disease-free at the end of the study period. The 5-year overall survival (OS) rate for all patients was 88.1%, and the 5-year OS rates for T1a, Tb, and T2 were 91.6%, 77.8%, and 89.9%, respectively.ConclusionsThe retrospective analysis showed a high rate of LC and larynx preservation in patients with T1-T2 GC by means of RT with or without chemotherapy. There was, however, no statistical difference in LC rates for the two types of therapy.


Evidence-based Complementary and Alternative Medicine | 2015

A Randomized, Double-Blind Pilot Trial of Hydrolyzed Rice Bran versus Placebo for Radioprotective Effect on Acute Gastroenteritis Secondary to Chemoradiotherapy in Patients with Cervical Cancer.

Yoshiyuki Itoh; Mika Mizuno; Mitsuru Ikeda; Rie Nakahara; Seiji Kubota; Junji Ito; Tohru Okada; Mariko Kawamura; Fumitaka Kikkawa; Shinji Naganawa

We aimed to evaluate the radioprotective effect of hydrolyzed rice bran (HRB) on acute gastroenteritis due to chemoradiotherapy for treatment of cervical cancer. This placebo-controlled, double-blind study was conducted as an exploratory investigation of the colitis-inhibiting effects of HRB in alleviating acute-phase gastrointestinal side effects of chemoradiotherapy. The study involved 20 patients (10 in the HRB group, 10 in the control group). The patients in the control group underwent the same chemoradiotherapy regimen as those in the HRB group, but they received a placebo instead of HRB. The diarrheal side effect assessment score was lower in the HRB than control group, and a trend toward a reduction in diarrhea symptoms was observed with the oral intake of HRB. Additionally, no significant difference was observed in the administration of intestinal regulators and antidiarrheal agents, but again the assessment score was lower in the HRB than control group, and diarrhea symptoms were alleviated with the oral intake of HRB. A trend toward no need for strong antidiarrheal agents was seen. Although this study was an exploratory clinical trial, the results suggest that HRB may relieve diarrhea, an acute-phase gastrointestinal side effect of chemoradiotherapy.


Nagoya Journal of Medical Science | 2016

A multicenter survey of stage T1 glottic cancer treated with radiotherapy delivered in 2.25-Gy fractions in clinical practice : An initial 5-year analysis

Yoshiyuki Itoh; Seiji Kubota; Mariko Kawamura; Yoshihito Nomoto; Takayuki Murao; Kouji Yamakawa; Shunichi Ishihara; Naoki Hirasawa; Akiko Asano; Shigeo Yanagawa; Shinji Naganawa

ABSTRACT The purpose of this study was to evaluate the acute and late toxicity as well as local control (LC) in T1 glottic cancer (GC) patients treated with hypofractionated radiotherapy (RT) in clinical practice. The Tokai Study Group for Therapeutic Radiology and Oncology started RT treatment with a dose of 2.25 Gy for T1 GC in 2011. Ten institutions combined data from 104 patients with T1 squamous cell carcinoma between 2011 and 2015. In total, 104 patients with T1 GC were irradiated with a standard radiation dose of 63 Gy in 28 fractions.The median follow-up duration was 18 (3.7–49.5) months. Acute grade 3 adverse events were observed in 7 patients, with 4 patients (5%) having dermatitis and 3 patients (4%) having mucositis. Late adverse events above grade 3 were not observed. Two patients developed local recurrence. The rates of acute adverse events in the present study were comparable to those in previous studies that have used 2 Gy fractions of RT.


Asian Pacific Journal of Cancer Prevention | 2018

Study Protocol: Prospective Study of Concurrent Chemoradiotherapy with S-1 and Hypofractionated Radiotherapy for Outpatients with Early Glottic Squamous Cell Carcinomas

Kana Kimura; Yoshiyuki Itoh; Tohru Okada; Seiji Kubota; Mariko Kawamura; Rie Nakahara; Yumi Oie; Yuka Kozai; Yuuki Takase; Hidenori Tsuzuki; Naoki Nishio; Mariko Hiramatsu; Yasushi Fujimoto; Takefumi Mizutani; Akihiro Hirakawa; Sinji Naganawa

Background: The recommended treatment strategies for early glottic carcinoma with intent of larynx preservation are primarily radiotherapy. However, the outcomes of radiotherapy for bulky T1 or T2 glottic carcinoma are unsatisfactory. We designed a protocol consisting of concurrent chemoradiotherapy using S-1 as the radiosensitizer. We have performed this protocol in patients with favorable T2 lesions and demonstrated its efficacy and safety. In contrast, we have treated non-bulky T1 glottic carcinomas with 2.25 Gy per fraction, for a total of 25-28 fractions, starting in 2011 to improve efficacy and shorten the treatment period. Since this treatment strategy was implemented for T1 disease, no local failure has occurred to date, and it appears to be almost as safe as radiotherapy using 2.0 Gy per fraction. With the aim of improving the local control rate and shortening the treatment period primarily for favorable T2 disease, we changed the dose of radiation in our protocol from 2.0 Gy to 2.25 Gy per fraction, for a total of 25 fractions (from 30 fractions). The present study aims to evaluate the efficacy and safety of this new protocol. Methods: This study will be conducted as a clinical, prospective, single-armed, non-randomized trial. Patients are to receive S-1 (55.3 mg /m2 /day, once daily) and radiotherapy (2.25 Gy per fraction, for a total of 25 fractions). S-1 and radiotherapy are started on the same day that radiotherapy is performed, 3-6 hours after oral administration of S-1. The primary study aim is the 3-year local control rate. The secondary study aims are overall survival, voice-preservation survival, disease-free survival, complete response rate, completion rate, and toxicity. Result and conclusion: This is the first single-center, non-randomized, prospective study of concurrent chemoradiotherapy with S-1 and hypofractionated radiotherapy to be conducted. The trial will evaluate the efficacy and safety of our protocol.


Archive | 2017

Optimized treatment strategy of radiotherapy for early glottic squamous cell carcinomas : An initial analysis

Kana Kimura; Yoshiyuki Itoh; Tohru Okada; Seiji Kubota; Mariko Kawamura; Rie Nakahara; Yumi Oie; Yuka Kozai; Yuuki Takase; Hidenori Tsuzuki; Naoki Nishio; Mariko Hiramatsu; Yasushi Fujimoto; Takefumi Mizutani; Shinji Naganawa

ABSTRACT The purpose of this study was to evaluate the clinical outcomes of radiotherapy for patients with T1/T2 glottic carcinoma. Patients with T1/T2 glottic carcinoma histopathologically diagnosed with squamous cell carcinoma and treated at our hospital between 2007 and 2015 were analyzed retrospectively. Our strategy for T1/T2 glottic carcinoma was as follows: radiotherapy alone with 2.25 Gy per fraction to a total of 25–28 fractions for patients with non-bulky T1 glottic carcinoma; concurrent chemoradiotherapy with oral S-1 and radiotherapy with 2 Gy per fraction to a total of 30 fractions for patients with T1 bulky/T2 favorable glottic carcinoma; or chemoradiotherapy with high-dose cisplatin and radiotherapy with 2 Gy per fraction to a total of 35 fractions for T2 unfavorable glottic carcinoma. Forty-eight patients were eligible. The median follow-up period among surviving patients was 38 months (range, 11–107). The disease was T1a in 23%, T1b in 13%, and T2 in 65% of patients. The 3-year local control rate in all patients, T1a, T1b, and T2 was 96.7%, 100%, 100%, and 96.0%, respectively. Of the 46 patients, one with T2 glottic carcinoma developed recurrent disease at the primary site, and one with T2 glottic carcinoma had lymph node recurrences in the neck. Acute Grade 3 dermatitis occurred in 8 (17%) patients and late Grade 2 hypothyroidism occurred in 2 (4%) patients. This retrospective study shows that our optimized treatment strategy of radiotherapy depending on the stage of early glottic carcinoma is not only effective but also well-tolerated.


Nagoya Journal of Medical Science | 2017

Postoperative chemoradiation therapy using high dose cisplatin and fluorouracil for high- and intermediate-risk uterine cervical cancer

Shinji Naganawa; Fumitaka Kikkawa; Tohru Okada; Junji Ito; Seiji Kubota; Rie Nakahara; Hiroaki Kajiyama; Kiyosumi Shibata; Akihiro Hirakawa; Mariko Kawamura; Yoshiyuki Itoh; Rise Miyauchi

ABSTRACT The purpose of this retrospective study was to analyze data in patients with stage IB–IIB uterine cervical cancer who were treated with concurrent chemoradiotherapy (CCRT) with high dose cisplatin and fluorouracil as postoperative adjuvant therapy. Between February 2003 and November 2011, 76 patients with FIGO stage IB–IIB cervical cancer were analyzed. Seventy patients were treated with postoperative CCRT and 6 patients were treated with radiation therapy alone. Data related to overall survival (OS), disease-free survival (DFS), toxicity, and failure pattern were analyzed. The median patient age was 45 years (range, 20–80 years). The median follow-up duration was 63 months (range, 10–125 months). Fifty-eight patients (76.3%) had a squamous cell histologic type, 55 patients (72.4%) had lymphovascular invasion, 31 patients (40.8%) had parametrial invasion, and 28 patients (36.8%) had lymph node metastases. Five-year OS and DFS were 96% and 92%, respectively. Five-year DFS in stage IB1 patients was significantly higher than in stage IB2–IIB patients (p = 0.022). Nineteen patients (25%) had grade 3 or 4 neutropenia, 13 patients (17.1%) had grade 3 anemia, and 2 patients (2.6%) had grade 3 thrombocytopenia, but none of these patients died from the disease. Three patients experienced chronic toxicity: one had bladder perforation, one had hydronephrosis, and one experienced ileus. CCRT as postoperative adjuvant therapy resulted in good survival and outcome without severe toxicity.


Journal of Radiation Research | 2017

Clinical outcomes of 125I brachytherapy with and without external-beam radiation therapy for localized prostate cancer: results from 300 patients at a single institution in Japan

Sayo Maki; Yoshiyuki Itoh; Seiji Kubota; Tohru Okada; Rie Nakahara; Junji Ito; Mariko Kawamura; Shinji Naganawa; Yasushi Yoshino; Takashi Fujita; Masashi Kato; Momokazu Gotoh; Mitsuru Ikeda

Abstract The aim of this study was to determine the outcomes and adverse events for 300 men with prostate cancer treated with 125iodine (125I) brachytherapy with and without external-beam radiation therapy (EBRT) at a single institution in Japan. Between February 2005 and November 2011, 300 consecutive patients with clinically localized prostate cancer were treated with 125I brachytherapy at the Nagoya University Hospital. A total of 271 men were treated with implants with doses of 145 Gy, and 29 men were treated with implants with doses of 110 Gy combined with EBRT (40–50 Gy/20–25 fractions). The median patient age was 69 years (range, 53–83 years). The median follow-up period was 53 months (range, 5–99 months). According to the National Comprehensive Cancer Network risk classification, 132 men (44%) had low-risk, 147 men (29%) had intermediate-risk and 21 men (7%) had high-risk disease. The 5-year overall survival rate, biochemical relapse–free survival rate, and disease-specific survival rates were 93.5%, 97.3% and 98.5%, respectively. Two men (0.6%) died of prostate cancer and 10 men (3.3%) died of other causes. Seventeen men (5.6%) experienced Grade 2 rectal bleeding in all: 12 (41.4%) of 29 in brachytherapy with EBRT, and 5 (1.8%) of 271 in brachytherapy alone. The rates of Grade 2 and 3 genitourinary toxicity were 1.0% and 1.7%, respectively. Excellent local control was achieved at our hospital for localized prostate cancer with 125I brachytherapy with and without EBRT. Gastrointestinal and genitourinary toxicities were acceptable.


Magnetic Resonance in Medical Sciences | 2008

Contrast-enhanced MR Imaging of Metastatic Brain Tumor at 3 Tesla: Utility of T1-weighted SPACE Compared with 2D Spin Echo and 3D Gradient Echo Sequence

Tomohiro Komada; Shinji Naganawa; Hiroshi Ogawa; Masaya Matsushima; Seiji Kubota; Hisashi Kawai; Hiroshi Fukatsu; Mitsuru Ikeda; Minako Kawamura; Yasuo Sakurai; Katsuya Maruyama


International Journal of Clinical Oncology | 2014

Primary CNS lymphoma treated with radiotherapy in Japan: a survey of patients treated in 2005–2009 and a comparison with those treated in 1985–2004

Yuta Shibamoto; Minako Sumi; Shunsuke Onodera; Haruo Matsushita; Chikao Sugie; Yukihisa Tamaki; Hiroshi Onishi; Eisuke Abe; Masahiko Koizumi; D. Miyawaki; Seiji Kubota; Etsuyo Ogo; Takuma Nomiya; Mitsuhiro Takemoto; Hideyuki Harada; I. Takahashi; Yoshio Ohmori; Naoya Ishibashi; Sunao Tokumaru; Kazunori Suzuki

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