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Dive into the research topics where Kenichiro Yabuki is active.

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Featured researches published by Kenichiro Yabuki.


European Archives of Oto-rhino-laryngology | 2010

Role of 18F-FDG PET in detecting primary site in the patient with primary unknown carcinoma

Kenichiro Yabuki; Mamoru Tsukuda; Choichi Horiuchi; Takahide Taguchi; Goshi Nishimura

The aim of this study was to verify the effectiveness of positron emission tomography (PET) in detecting primary sites in carcinoma of unknown primary (CUP) patients. In this study, CUP represented a group of heterogeneous tumors that shared the clinical manifestation of metastatic carcinoma with no obvious primary site at the time of first diagnosis, which included clinical investigations, computed tomography, magnetic resonance imaging and panendoscopy. We reviewed the records of 24 patients with CUP between January 1995 and December 2009. The patients who demonstrated additional tracer uptake sites other than previously known metastatic lesions by PET scan were done direct biopsies for the sites of accumulation. Patients who had a negative PET scan or for whom the primary site could not be identified by direct biopsies underwent examination under anesthesia of the at-risk occult tumor sites. PET scan demonstrated focal accumulation suspicious for primary tumor in 12 (50.0%) of 24 patients: tonsil 5, nasopharynx 3, hypopharynx 1, tongue 1, larynx 1, and maxillary sinus 1. A subsequent biopsy of these sites revealed primary cancer in 9 (37.5%) of 24 patients: tonsil 5, nasopharynx 1, hypopharynx 1, tongue 1, and maxillary sinus 1. In the remaining three patients, no malignant cells were found by the biopsy of the accumulated area: nasopharynx 2, larynx 1. PET scans increase the yield of primary tumor by 37.5%. The sensitivity, specificity for PET scan were 80.8, 76.9%, respectively. PET scanning is useful in detecting primary cancer of CUP patients.


PLOS ONE | 2015

Predictive and Prognostic Value of Metabolic Tumor Volume (MTV) in Patients with Laryngeal Carcinoma Treated by Radiotherapy (RT) / Concurrent Chemoradiotherapy (CCRT)

Kenichiro Yabuki; Osamu Shiono; Masanori Komatsu; Daisuke Sano; Goshi Nishimura; Masahiro Takahashi; Takahide Taguchi; Tomio Inoue; Nobuhiko Oridate

Purpose To evaluate the predictive and prognostic value of pretreatment metabolic tumor volume (MTV) in patients with treated by radiotherapy (RT) or concurrent chemoradiotherapy (CCRT). Methods We reviewed the records of 118 patients with newly diagnosed laryngeal carcinoma, who had been treated by RT or CCRT. Pretreatment positron emission tomography (PET) was performed, and MTV values were obtained by contouring margins of standardized uptake value. Clinical factors and MTV were analyzed for their association with survival. Results Patients with residual disease showed a significantly higher MTV than those with a complete response (CR) after primary treatment. Univariate analysis showed that the patients with a high MTV had a significantly lower disease-free survival (DFS) (p < 0.001). Subsite (p = 0.010), T-stage (p < 0.001), nodal metastasis (p < 0.001) and clinical stage (p < 0.001) also correlated significantly with DFS. In the multivariate analysis, MTV and clinical stage were both found to be independent prognostic factors for DFS (p = 0.001, p = 0.034, respectively). The 3-year DFS for patients with a high MTV were significantly poorer than those with a low MTV (p < 0.001). Conclusions MTV of the primary tumor is a significant prognostic factor for DFS in patients with laryngeal carcinoma treated by RT or CCRT. The results imply that MTV could be an important factor when planning treatment and follow-up for patients with laryngeal carcinoma.


Japanese Journal of Clinical Oncology | 2014

Concurrent chemoradiotherapy with docetaxel, cisplatin and 5-fluorouracil (TPF) in patients with locally advanced squamous cell carcinoma of the head and neck

Masanori Komatsu; Osamu Shiono; Takahide Taguchi; Yasunori Sakuma; Goushi Nishimura; Daisuku Sano; Naoko Sakuma; Kenichiro Yabuki; Yasuhiro Arai; Masahiro Takahashi; Junichi Isitoya; Nobuhiko Oridate

OBJECTIVE Compared with radiotherapy alone, concurrent chemoradiotherapy significantly improves survival rates for patients with squamous cell carcinoma of the head and neck. The aim of this study was to retrospectively evaluate the efficacy, toxicity and long-term prognosis of concurrent chemoradiotherapy with docetaxel, cisplatin and 5-fluorouracil chemotherapy. METHODS A total of 140 patients were enrolled and evaluated. Patients were received two cycles of docetaxel, cisplatin and 5-fluorouracil chemotherapy (docetaxel [50 mg/m(2): Day 1], cisplatin [60 mg/m(2): Day 4] and continuous 5-fluorouracil [600 mg/m(2)/day: Days 1-5]) during definitive radiotherapy. RESULTS The overall response rate was 97.1%. The 3 and 5-year overall survival rates were 83.3 and 79.2%, respectively. The 3 and 5-year disease-specific survival rates were 84.2 and 80.0%, respectively. Among patients with laryngeal or hypopharyngeal carcinoma, the 5-year laryngectomy-free survival rate was 64.9%. CONCLUSIONS Concurrent chemoradiotherapy with docetaxel, cisplatin and 5-fluorouracil showed excellent survival and organ preservation rates for the patients with locally advanced squamous cell carcinoma of the head and neck.


Head and Neck-journal for The Sciences and Specialties of The Head and Neck | 2016

Prognostic significance of metabolic tumor volume in patients with piriform sinus carcinoma treated by radiotherapy with or without concurrent chemotherapy

Kenichiro Yabuki; Daisuke Sano; Osamu Shiono; Yasuhiro Arai; Hideaki Takahashi; Yoshihiro Chiba; Teruhiko Tanabe; Goshi Nishimura; Masahiro Takahashi; Takahide Taguchi; Tomohiro Kaneta; Masaharu Hata; Nobuhiko Oridate

The purpose of this study was to elucidate the prognostic significance of the pretreatment metabolic tumor volume (MTV) in patients with piriform sinus carcinoma treated by radiation‐based therapy.


Laryngoscope | 2017

Surgery-based versus radiation-based treatment strategy for a high metabolic volume laryngeal cancer

Kenichiro Yabuki; Daisuke Sano; Osamu Shiono; Yasuhiro Arai; Yoshihiro Chiba; Teruhiko Tanabe; Goshi Nishimura; Masahiro Takahashi; Takahide Taguchi; Tomohiro Kaneta; Masaharu Hata; Nobuhiko Oridate

We previously reported that the metabolic tumor volume (MTV) of a primary tumor was an independent prognostic factor for survival in laryngeal carcinoma treated by radiotherapy (RT)‐based protocol. The purpose of this study was to evaluate the difference in survival outcomes between surgery‐based and RT‐based treatment in patients with a MTV laryngeal cancer.


Auris Nasus Larynx | 2016

Reduction surgery using a combination of a stereolithographic model and navigation system for ossifying fibroma with secondary central giant cell granuloma.

Yasuhiro Arai; Yoshihiro Chiba; Shigeaki Umeda; Yoshihito Ohara; Toshinori Iwai; Masanori Komatsu; Kenichiro Yabuki; Daisuke Sano; Nobuhiko Oridate

Both central giant cell granuloma (CGCG) and ossifying fibroma (OF) are relatively common diseases. The synchronous presentation of CGCG and OF is, however, an extremely rare occurrence. We present an unusual case with the synchronous presentation of these two diseases in the maxilla and introduce a surgical strategy based on a combination of the stereolithographic model and navigation system for the treatment of gigantic OF with secondary CGCG.


Translational cancer research | 2018

Analysis of prognostic factors, including the incidence of second primary cancer, in patients with early stage laryngeal squamous cell carcinoma treated by radiation-based therapy

Kaname Sato; Kenichiro Yabuki; Daisuke Sano; Yasuhiro Arai; Yoshihiro Chiba; Teruhiko Tanabe; Goshi Nishimura; Masaharu Hata; Nobuhiko Oridate

Background: The purpose of this study was to elucidate the efficacy of concurrent chemotherapy and analyze prognostic factors in the radiation-based therapy for early stage laryngeal squamous cell carcinoma (ELSCC). Methods: The records of 97 patients with ELSCC treated by radiation-based therapy from 2004 to 2016 were retrospectively reviewed. Eighty-one patients were treated with the combined-agent regimens during the treatment. Of the 81 patients, 58 were treated with S-1 regimen and 23 with other regimens. Clinical factors, such as concurrent chemotherapy, non-glottic subsite and the incidence of second primary cancer (SPC) were analyzed for their association with survival. Results: From the analysis of all patients, the 5-year overall survival (OS) rates were found to be significantly poorer for patients with non-glottic cancer compared to those with glottic cancer (P Conclusions: Non-glottic subsite and SPC were associated with worsened survival. CCRT with S-1 can be a useful treatment option for stage II ELSCC.


JMIR Research Protocols | 2018

Postoperative Bio-Chemoradiotherapy Using Cetuximab and Docetaxel in Patients With Cis-Platinum–Intolerant Core High-Risk Head and Neck Cancer: Protocol of a Phase 2 Nonrandomized Clinical Trial

Goshi Nishimura; Hiromitsu Hatakeyama; Osamu Shiono; Masataka Taguri; Masanori Komatsu; Daisuke Sano; Naoko Sakuma; Kenichiro Yabuki; Yasuhiro Arai; Kunihiko Shibata; Yoshihiro Chiba; Teruhiko Tanabe; Nobuhiko Oridate

Background We confirmed the safety of postoperative bio-chemoradiotherapy using cetuximab and docetaxel in a small number of patients with cis-platinum–intolerant core high-risk head and neck cancer. Objective To assess treatment efficacy, we planned a phase 2 study of postoperative bio-chemoradiotherapy for patients with cis-platinum–intolerant core high-risk head and neck cancer and will compare the results to those of previously collected radiotherapy data. Methods Patients who underwent definitive surgery for oral cavity, laryngeal, oropharyngeal, or hypopharyngeal advanced cancer, whose postoperative pathological results indicated core high risk for recurrence (eg, positive margin in the primary site or extranodal extension) and who were cis-platinum–intolerant, will undergo postoperative bio-chemoradiotherapy. The primary end point is 2-year disease-free survival. Results The expected 2-year disease-free survival is set at 55%, and the calculated sample size is 35 patients, according to a statistical analysis based on previous reports. Conclusions This treatment method is expected to improve the survival rate of patients with severe head and neck cancer. Trial Registration UMIN Clinical Trials Registry UMIN000031835; https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ ctr_view.cgi?recptno=R000036355 (Archived by WebCite at http://www.webcitation.org/71fejVjMr)


Auris Nasus Larynx | 2018

Predictive value of the Hyodo score in endoscopic evaluation of aspiration during swallowing

Yoshihiro Chiba; Daisuke Sano; Yukiko Ikui; Goshi Nishimura; Kenichiro Yabuki; Yasuhiro Arai; Teruhiko Tanabe; Hidetaka Ikemiyagi; Hiroshi Hyakusoku; Nobuhiko Oridate

OBJECTIVE The Hyodo scoring system during the endoscopic procedure has been proposed as a new tool for evaluating oral intake feasibility. However, the effectiveness of the information obtained from this procedure in predicting aspiration is not fully elucidated. The aim of this study was to assess the significance of clinical factors, including Hyodo scores, for predicting the risk of aspiration. METHODS Five hundred and twenty-eight endoscopic swallowing examinations were performed. Clinical factors, including age, sex, disease type, history of aspiration pneumonia, cognitive function, presence of tracheostomy, presence of vocal cord paralysis, consciousness level on the Japan Coma Scale, ECOG Performance Status, serum albumin level and Hyodo score, were obtained for each examination. The relationship between each of these factors and the presence of aspiration during endoscopic procedure was evaluated. RESULTS Three hundred and thirty-two patients (62.9%) were scored less than 5, 153 (29.0%) were scored between 5 and 8, and 43 (8.1%) were scored above 8. The number of patients with aspiration was 133 (25.2%). ROC analysis revealed that a cut-off point of 6 for Hyodo score was effective for predicting aspiration, with a sensitivity of 0.65 and a specificity of 0.86. History of aspiration pneumonia (OR 1.87, P<0.001), vocal cord paralysis (OR 2.23, P<0.001), PS≥3 (OR 2.47, P<0.001) and Hyodo score>6 (OR 9.08, P<0.001) were found to be independent predictive factors for aspiration. CONCLUSION The Hyodo scoring method was easy for otolaryngologists to perform and the scores were useful for predicting aspiration with moderate sensitivity and high specificity. Hyodo score>6, history of aspiration pneumonia, vocal cord paralysis, and PS≥3 were independent predictive factors for aspiration and that a Hyodo score above 6 was the statistically strongest predictor for aspiration.


Acta Oto-laryngologica | 2018

Cochlear volume as a predictive factor for residual-hearing preservation after conventional cochlear implantation

Masahiro Takahashi; Yasuhiro Arai; Naoko Sakuma; Kenichiro Yabuki; Daisuke Sano; Goshi Nishimura; Nobuhiko Oridate; Shin-ichi Usami

Abstract Objective: The preservation of residual hearing after conventional cochlear implantation (CI) is frequently observed when atraumatic soft surgery is adopted. The purpose of this study was to elucidate the predictive factors for residual hearing preservation after atraumatic CI. Patients: This study included 46 patients who underwent CI based on an atraumatic technique using a standard-length flexible electrode implant through a round window approach. Main outcome measure: Cochlear volume was measured using magnetic resonance imaging (MRI). Cochlear duct length (CDL) was taken as the length of the scala media measured using computed tomography (CT). The association between residual hearing preservation and cochlear volume/CDL was then examined. Result: Cochlear volume and CDL were significantly larger in patients with complete hearing preservation than in those with hearing loss. Multivariate logistic regression analysis revealed that cochlear volume was a significant predictive factor for residual hearing preservation. Conclusion: Residual hearing preservation after conventional CI was observed in patients with a larger cochlear volume and longer CDL. Cochlear volume could be a predictive factor for residual hearing preservation after conventional CI.

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Daisuke Sano

Yokohama City University

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Yasuhiro Arai

Yokohama City University Medical Center

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Osamu Shiono

Yokohama City University Medical Center

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