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Dive into the research topics where Kazuma Kobayashi is active.

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Featured researches published by Kazuma Kobayashi.


European Journal of Gastroenterology & Hepatology | 2001

Successful treatment of bleeding due to ileal varices in a patient with hepatocellular carcinoma.

Kazuma Kobayashi; Junzo Yamaguchi; Akihiko Mizoe; Ichiro Isomoto; Tsuyoshi Koshiishi; Kunihide Izawa; Takashi Kanematsu

This case report concerns a 62-year-old female who was known to have cirrhosis. An endoscopic examination showed no evidence of haemorrhaging due to either oesophageal or gastric varices. Angiographic studies demonstrated extravasation from the ileal varices. There was a prominent arterio-portal shunt in the liver, and the shunt was considered to be a contributing factor to induce portal hypertension and variceal bleeding in the ileum. Therefore, transcatheter arterial embolization was performed, but was unsuccessful. As a result, the patient underwent a laparotomy, and a dilatating ileocaecal vein and a communicating ovarian vein were selectively ligated. Following the procedure, the haemorrhaging stopped and she then recovered. The patient is doing well 21 months after surgery at the time of writing.


BMC Cancer | 2006

A phase II study of LFP therapy (5-FU (5-fluorourasil) continuous infusion (CVI) and Low-dose consecutive (Cisplatin) CDDP) in advanced biliary tract carcinoma

Kazuma Kobayashi; Akihito Tsuji; Sojiro Morita; Tadashi Horimi; Tetsuhiko Shirasaka; Takashi Kanematsu

BackgroundUnresectable biliary tract carcinoma is known to demonstrate a poor prognosis. We conducted a single arm phase II study of LFP therapy (5-FU (5-fluorourasil) continuous infusion (CVI) and Low-dose consecutive (Cisplatin) CDDP) for advanced biliary tract malignancies basically on an outpatient basis.MethodsBetween February 1996 and September 2003, 42 patients were enrolled in this trial.LFP therapyBy using a total implanted CV-catheter system, 5-FU (160 mg/m2/day) was continuously infused over 24 hours for 7 consecutive days and CDDP (6 mg/m2/day) was infused for 30 minutes twice a week as one cycle. The administration schedule consisted of 4 cycles as one course. RESIST criteria (Response evaluation criteria for solid tumors) and NCI-CTC (National Cancer Institute-Common Toxicity Criteria) (ver.3.0) were used for evaluation of this therapy. The median survival time (MST) and median time to treatment failure (TTF) were calculated by the Kaplan-Meier method.ResultsPatients characteristics were: mean age 66.5(47–79): male 24 (54%): BDca (bile duct carcinoma) 27 GBca (Gallbladder carcinoma) 15: locally advanced 26, postoperative recurrence 16. The most common toxicity was anemia (26.2%). Neither any treatment related death nor grade 4 toxicity occurred. The median number of courses of LFP Therapy which patients could receive was two (1–14). All the patients are evaluable for effects with an over all response rates of 42.9% (95% confidence interval C.I.: 27.7–59.0) (0 CR, 18 PR, 13 NC, 11 PD). There was no significant difference regarding the anti tumor effects against both malignant neoplasms. Figure 2 Shows the BDca a longer MST and TTF than did GBca (234 vs 150, 117 vs 85, respectively), but neither difference was statistically significant.The estimated MST and median TTF were 225 and 107 days, respectively. The BDca had a longer MST and TTF than GBca (234 vs 150, 117 vs 85, respectively), but neither difference was statistically significant.ConclusionLFP therapy appears to be useful modality for the clinical management of advanced biliary tract malignancy.


Radiotherapy and Oncology | 2015

Dosimetric variations due to interfraction organ deformation in cervical cancer brachytherapy

Kazuma Kobayashi; Naoya Murakami; Akihisa Wakita; Satoshi Nakamura; Hiroyuki Okamoto; Rei Umezawa; Kana Takahashi; Koji Inaba; Hiroshi Igaki; Yoshinori Ito; Naoyuki Shigematsu; Jun Itami

We quantitatively estimated dosimetric variations due to interfraction organ deformation in multi-fractionated high-dose-rate brachytherapy (HDRBT) for cervical cancer using a novel surface-based non-rigid deformable registration. As the number of consecutive HDRBT fractions increased, simple addition of dose-volume histogram parameters significantly overestimated the dose, compared with distribution-based dose addition.


Journal of Contemporary Brachytherapy | 2016

The role of interstitial brachytherapy in the management of primary radiation therapy for uterine cervical cancer

Naoya Murakami; Kazuma Kobayashi; Tomoyasu Kato; Satoshi Nakamura; Akihisa Wakita; Hiroyuki Okamoto; Satoshi Shima; Keisuke Tsuchida; Tairo Kashihara; Ken Harada; Kana Takahashi; Rei Umezawa; Koji Inaba; Yoshinori Ito; Hiroshi Igaki; Jun Itami

Purpose The aim of this study was to report the clinical results of uterine cervical cancer patients treated by primary radiation therapy including brachytherapy, and investigate the role of interstitial brachytherapy (ISBT). Material and methods All consecutive uterine cervical cancer patients who were treated by primary radiation therapy were reviewed, and those who were treated by ISBT were further investigated for clinical outcomes and related toxicities. Results From December 2008 to October 2014, 209 consecutive uterine cervical cancer patients were treated with primary radiation therapy. Among them, 142 and 42 patients were treated by intracavitary and hybrid brachytherapy, respectively. Twenty-five patients (12%) were treated by high-dose-rate (HDR)-ISBT. Five patients with distant metastasis other than para-aortic lymph node were excluded, and 20 patients consisted of the analysis. Three-year overall survival (OS), progression-free survival (PFS), and local control (LC) rate were 44.4%, 38.9%, and 87.8%, respectively. Distant metastasis was the most frequent site of first relapse after HDR-ISBT. One and four patients experienced grade 3 and 2 rectal bleeding, one grade 2 cystitis, and two grade 2 vaginal ulcer. Conclusions Feasibility and favorable local control of interstitial brachytherapy for locally advanced cervical cancer was demonstrated through a single institutional experience with a small number of patients.


Journal of Contemporary Brachytherapy | 2015

A total EQD2 greater than 85 Gy for trachea and main bronchus D2cc being associated with severe late complications after definitive endobronchial brachytherapy.

Naoya Murakami; Kazuma Kobayashi; Satoshi Nakamura; Akihisa Wakita; Hiroyuki Okamoto; Keisuke Tsuchida; Tairo Kashihara; Ken Harada; Mayuka Yamada; Shuhei Sekii; Kana Takahashi; Rei Umezawa; Koji Inaba; Yoshinori Ito; Hiroshi Igaki; Jun Itami

Purpose The endobronchial brachytherapy (EBBT) is an established treatment method for tumors of the tracheobronchial system, however, little is known about the tolerance dose for organ at risk (OAR) in EBBT. The purpose of this study is to analyze patients with superficial bronchial carcinoma treated with definitive EBBT, and to investigate a relationship between late complications and dose for OAR. Material and methods Endobronchial brachytherapy was performed 6 Gy per fraction for three to four fractions with or without external beam radiation therapy (EBRT). For the purpose of dosimetric analysis, the wall of the lower respiratory tract (LRT: trachea, main bronchus, and lobar bronchiole), trachea, and main bronchus (TMB) was extracted. D0.5cc, D1cc, and D2cc of LRT and TMB were calculated in each EBBT session and added together. V100, V150, and V200 of LRT were also calculated. Results Between March 2008 and April 2014, EBBT was performed in 14 patients for curative intent. The 2-year overall survival (OS), progression-free survival (PFS), and local recurrence free survival (LRFS) was 82.1%, 77.9%, and 91.7%, respectively. There was one patient with grade 5, one grade 4, and three grade 3 obstruction of trachea or bronchus. The mean EQD2 of LRT D2cc, TMB D2cc, D1cc, and D0.5cc of patients with or without late severe respiratory complications was significantly different between two groups (p = 0.018, 0.008, 0.009, and 0.013, respectively). The 2-year incidence rates of late severe complications in patients with TMB D2cc ≤ 85 Gy in EQD2 and > 85 Gy were 0% and 83.3%, respectively with a statistically significance (p = 0.014). Conclusions It was discovered that TMB D2cc > 85 Gy in EQD2 is a strong risk factor for severe late respiratory complication after EBBT.


Oncology | 2011

Phase II Study of Bolus 5-Fluorouracil and Leucovorin Combined with Weekly Paclitaxel as First-Line Therapy for Advanced Gastric Cancer

Junichi Matsubara; Yasuhiro Shimada; Ken Kato; Yushi Nagai; Satoru Iwasa; Takako Eguchi Nakajima; Tetsuya Hamaguchi; Yasuhide Yamada; Seiichi Takagi; Kazuma Kobayashi; Akira Yoshioka; Norisuke Nakayama; Akihito Tsuji

Objective: We evaluated the efficacy and safety of bolus 5-fluorouracil (5-FU) and leucovorin combined with weekly paclitaxel (FLTAX) in advanced gastric cancer (GC) patients. Methods: Patients with untreated stage IV GC received paclitaxel 80 mg/m2 as a 1-hour infusion, followed by 5-FU 600 mg/m2 as a bolus infusion and L-leucovorin 250 mg/m2 as a 2-hour infusion on days 1, 8 and 15. Treatment cycles were repeated every 28 days. The primary endpoint was response rate. Results: Thirty-five patients were enrolled. The median age was 62 years (range 34–75). Twenty-one patients (60%) had diffuse-type cancer and 11 had peritoneal metastasis. The confirmed response rate was 43% (95% CI 26–61) with 15 partial responses. Stable disease was observed in 16 (46%) patients. Median progression-free survival and overall survival were 6.8 months (95% CI 5.8–7.4) and 16.2 months (95% CI 10.0–22.8), respectively. Grade 3–4 adverse events were: neutropenia (54%), febrile neutropenia (3%), diarrhea (6%) and sensory neuropathy (11%). Conclusion: FLTAX showed a desirable safety profile, and the efficacy against advanced GC was encouraging. FLTAX may be a good option for GC patients with deteriorated general condition, and a randomized clinical trial in such patients is currently underway.


Laryngoscope | 2014

Expression of EpCAM and prognosis in early-stage glottic cancer treated by radiotherapy

Naoya Murakami; Taisuke Mori; Seiichi Yoshimoto; Yoshinori Ito; Kazuma Kobayashi; Harada Ken; Mayuka Kitaguchi; Shuhei Sekii; Kana Takahashi; Kotaro Yoshio; Koji Inaba; Madoka Morota; Minako Sumi; Jun Itami

Treatment of head and neck squamous cell carcinoma (HNSCC) often requires radiotherapy, but relapse can occur. There is, therefore, an urgent need for the identification of a predictive novel biomarker for radiosensitivity. The epithelial cell adhesion molecule (EpCAM) has been shown to promote the transformation of malignant tumors, and EpCAM may have prognostic significance, but it is not known if EpCAM determines prognosis, especially with respect to radiotherapy. Therefore, we determined the incidence of the expression of EpCAM in HNSCC and analyzed the prognostic value in patients with early‐stage glottic cancer treated with radiotherapy.


Applied Radiation and Isotopes | 2016

In vivo spatial correlation between 18F-BPA and 18F-FDG uptakes in head and neck cancer

Kazuma Kobayashi; Hiroaki Kurihara; Yoshiaki Watanabe; Naoya Murakami; Koji Inaba; Satoshi Nakamura; Akihisa Wakita; Hiroyuki Okamoto; Rei Umezawa; Kana Takahashi; Hiroshi Igaki; Yoshinori Ito; Seiichi Yoshimoto; Naoyuki Shigematsu; Jun Itami

BACKGROUND AND PURPOSE Borono-2-(18)F-fluoro-phenylalanine ((18)F-BPA) has been used to estimate the therapeutic effects of boron neutron capture therapy (BNCT), while (18)F-fluorodeoxyglucose ((18)F-FDG) is the most commonly used positron emission tomography (PET) radiopharmaceutical in a routine clinical use. The aim of the present study was to evaluate spatial correlation between (18)F-BPA and (18)F-FDG uptakes using a deformable image registration-based technique. MATERIAL AND METHODS Ten patients with head and neck cancer were recruited from January 2014 to December 2014. All patients underwent whole-body (18)F-BPA PET/computed tomography (CT) and (18)F-FDG PET/CT within a 2-week period. For each patient, (18)F-BPA PET/CT and (18)F-FDG PET/CT images were aligned based on a deformable image registration framework. The voxel-by-voxel spatial correlation of standardized uptake value (SUV) within the tumor was analyzed. RESULTS Our image processing framework achieved accurate and validated registration results for each PET/CT image. In 9/10 patients, the spatial distribution of SUVs between (18)F-BPA and (18)F-FDG showed a significant, positive correlation in the tumor volume. CONCLUSIONS Deformable image registration-based voxel-wise analysis demonstrated a spatial correlation between (18)F-BPA and (18)F-FDG uptakes in the head and neck cancer. A tumor sub-volume with a high (18)F-FDG uptake may predict high accumulation of (18)F-BPA.


Thoracic Cancer | 2018

Relationship between UGT1A1*27 and UGT1A1*7 polymorphisms and irinotecan-related toxicities in patients with lung cancer

Minoru Fukuda; Manabu Okumura; Tomomi Iwakiri; Kazuhiko Arimori; Takuya Honda; Kazuma Kobayashi; Hiroaki Senju; Shinnosuke Takemoto; Takaya Ikeda; Hiroyuki Yamaguchi; Katsumi Nakatomi; Nobuko Matsuo; Hiroshi Mukae; Kazuto Ashizawa

The objective of this study was to evaluate the effects of gene polymorphisms, including UGT1A1*7, *27, and *29, on the safety of irinotecan therapy.


Journal of Contemporary Brachytherapy | 2016

Dose reconstruction technique using non-rigid registration to evaluate spatial correspondence between high-dose region and late radiation toxicity: A case of tracheobronchial stenosis after external beam radiotherapy combined with endotracheal brachytherapy for tracheal cancer

Kazuma Kobayashi; Naoya Murakami; Koji Inaba; Akihisa Wakita; Satoshi Nakamura; Hiroyuki Okamoto; Jun Sato; Rei Umezawa; Kana Takahashi; Hiroshi Igaki; Yoshinori Ito; Naoyuki Shigematsu; Jun Itami

Purpose Small organ subvolume irradiated by a high-dose has been emphasized to be associated with late complication after radiotherapy. Here, we demonstrate a potential use of surface-based, non-rigid registration to investigate how high-dose volume topographically correlates with the location of late radiation morbidity in a case of tracheobronchial radiation stenosis. Material and methods An algorithm of point set registration was implemented to handle non-rigid registration between contour points on the organ surfaces. The framework estimated the global correspondence between the dose distribution and the varying anatomical structure. We applied it to an 80-year-old man who developed tracheobronchial stenosis 2 years after high-dose-rate endobronchial brachytherapy (HDR-EBT) (24 Gy in 6 Gy fractions) and external beam radiotherapy (EBRT) (40 Gy in 2 Gy fractions) for early-stage tracheal cancer. Results and conclusions Based on the transformation function computed by the non-rigid registration, irradiated dose distribution was reconstructed on the surface of post-treatment tracheobronchial stenosis. For expressing the equivalent dose in a fractional dose of 2 Gy in HDR-EBT, α/β of linear quadratic model was assumed as 3 Gy for the tracheal bronchus. The tracheobronchial surface irradiated by more than 100 Gyαβ3 tended to develop severe stenosis, which attributed to a more than 50% decrease in the luminal area. The proposed dose reconstruction technique can be a powerful tool to predict late radiation toxicity with spatial consideration.

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