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In Vivo Dosimetry of an Anthropomorphic Phantom Using the RADPOS for Proton Beam Therapy

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International Journal of Medical Physics, Clinical Engineering and Radiation Oncology 2016年第3期5卷 177-183页

作者： ryosuke Kohno Hidenori yamaguchi Kana Motegi Kenji Hotta Shie Nishioka Tetsuo Akimoto National Cancer Center Hospital East Kashiwa Japan Graduate School of Pure and Applied Sciences University of Tsukuba Tsukuba Japan National Cancer Center Hospital Tokyo Japan

The radiation positioning system (RADPOS) combines an electromagnetic positioning sensor with metal oxide semiconductor field-effect transistor (MOSFET) dosimetry, enabling simultaneous online measurement of dose and spatial position. Evaluation points can be determined with the RADPOS. The accuracy of in-vivo proton dosimetry was evaluated using the RADPOS and an anthropomorphic head and neck phantom. MOSFET doses measured at 3D positions obtained with the RADPOS were compared with treatment plan values calculated using a simplified Monte Carlo (SMC) method. MOSFET responses, which depend strongly on the linear energy transfer of the proton beam, were corrected using the SMC method. The SMC method was used to calculate only dose deposition determined by the experimental depth-dose distribution and lateral displacement of protons due to the multiple scattering effect in materials and incident angle. This method thus enabled rapid calculation of accurate doses in even heterogeneities. In vivo dosimetry using the RADPOS, as well as MOSFET doses, agreed with SMC calculations in the range of ?3.0% to 8.3%. Most measurement errors occurred because of uncertainties in dose calculations due to the 1-mm position error. The results indicate that uncertainties in measurement position can be controlled successfully within 1 mm when using the RADPOS with in-vivo proton dosimetry.

关键词： RADPOS MOSFET In Vivo Dosimetry Position Sensor Proton Beam Therapy

High total Joule heat increases the risk of post-endoscopic submucosal dissection electrocoagulation syndrome after colorectal endoscopic submucosal dissection

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World Journal of Gastroenterology 2021年第38期27卷 6442-6452页

作者： Masanori Ochi ryosuke Kawagoe Toshiro Kamoshida Yukako Hamano Haruka Ohkawara Atsushi Ohkawara Nobushige Kakinoki Yuji yamaguchi Shinji Hirai Akinori Yanaka Kiichiro Tsuchiya Department of Gastroenterology Hitachi General HospitalHitachi City 317-0077IbarakiJapan Department of Gastroenterology Faculty of MedicineUniversity of TsukubaTsukuba 305-8576IbarakiJapan

BACKGROUND We hypothesized that thermal damage accumulation during endoscopic submucosal dissection(ESD)causes the pathogenesis of post-ESD electrocoagulation syndrome(PECS).AIM To determine the association between Joule heat and the onset of PECS.METHODS We performed a retrospective cohort study in patients who underwent colorectal ESD from May 2013 to March 2021 in Japan.We developed a novel device that measures swift coagulation time with a sensor adjacent to the electrosurgical coagulation unit foot switch,which enabled us to calculate total Joule heat.PECS was defined as localized abdominal pain(visual analogue scale≥30 mm during hospitalization or increased by≥20 mm from the baseline)and fever(temperature≥37.5 degrees or white blood cell count≥10000μ/L).Patients exposed to more or less than the median Joule heat value were assigned to the high and low Joule heat groups,respectively.Statistical analyses included Mann-Whitney U and chisquare tests and logistic regression and receiver operating characteristic curve(ROC)analyses.RESULTS We evaluated 151 patients.The PECS incidence was 10.6%(16/151 cases),and all patients were followed conservatively and discharged without severe complications.In multivariate analysis,high Joule heat was an independent PECS risk factor.The area under the ROC curve showing the correlation between PECS and total Joule heat was high[0.788(95%confidence interval:0.666-0.909)].CONCLUSION Joule heat accumulation in the gastrointestinal wall is involved in the onset of PECS.ESD-related thermal damage to the peeled mucosal surface is probably a major component of the mechanism underlying PECS.

关键词： Post-endoscopic submucosal dissection electrocoagulation syndrome Joule heat Colorectal endoscopic submucosal dissection Colorectal neoplasms Electrocoagulation Gastrointestinal tract

Evaluation of novel slim biopsy forceps for diagnosis of biliary strictures: Single-institutional study of consecutive 360 cases(with video)

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World Journal of Gastroenterology 2017年第35期23卷 6429-6436页

作者： Kenjiro Yamamoto Takayoshi Tsuchiya Takao Itoi Shujiro Tsuji Reina Tanaka ryosuke Tonozuka Mitsuyoshi Honjo Shuntaro Mukai Kentaro Kamada Mitsuru Fujita Yasutsugu Asai Yukitoshi Matsunami Yuichi Nagakawa Hiroshi yamaguchi Atsushi Sofuni Department of Gastroenterology and Hepatology Tokyo Medical University Third Department of Surgery Tokyo Medical University Department of Pathology Tokyo Medical University

AIM To evaluate the feasibility and reliability of endoscopic transpapillary bile duct biopsy for the diagnosis of biliary strictures.METHODS A total of 360 patients(241 men) who underwent endoscopic retrograde cholangiopancreatography for biliary strictures with biopsy from April 2012 to March 2016 at Tokyo Medical University Hospital were retrospectively reviewed. This study was approved by our Institutional Review Board(No. 3516). Informed consent was obtained from all individual participants included in this study. The biopsy specimens were obtained using a novel slim biopsy forceps(Radial Jaw 4P, Boston Scientific, Boston, MA, United States).RESULTS The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 69.6%, 100%, 100%, 59.1%, and 78.8%, respectively. The sensitivity was 75.6% in bile duct cancer, 64% in pancreatic cancer, 61.1% in gallbladder cancer, and 57.1% in metastasis. In bile duct cancer, a lower sensitivity was observed for perihilar bile duct stricture(68.7%) than for distal bile duct stricture(83.1%). In terms of the stricture lengths of pancreatic cancer, gallbladder cancer, and metastasis, a longer stenosis resulted in a better sensitivity. In particular, there was a significant difference between pancreatic cancer and gallbladder cancer(P < 0.05). One major complication was perforation of the extrahepatic bile duct with bile leakage. CONCLUSION Endoscopic transpapillary biopsy alone using novel slim biopsy forceps is feasible and reliable, but restrictive. Biopsy should be performed in consideration of the stricture level, stricture length, and cancer type.

关键词： Endoscopic transpapillary biopsy Biopsy forceps Biliary stricture Bile duct cancer Endoscopic retrograde cholangiography

Lateral pelvic lymph nodes for rectal cancer:A review of diagnosis and management

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World Journal of Gastrointestinal Oncology 2021年第10期13卷 1412-1424页

作者： Shimpei Ogawa Michio Itabashi Yuji Inoue Takeshi Ohki Yoshiko Bamba Kurodo Koshino ryosuke Nakagawa Kimitaka Tani Hisako Aihara Hiroka Kondo Shigeki yamaguchi Masakazu Yamamoto Department of Surgery Institute of GastroenterologyTokyo Women's Medical UniversityTokyo 162-8666Japan

The current status and future prospects for diagnosis and treatment of lateral pelvic lymph node(LPLN)metastasis of rectal cancer are described in this review.Magnetic resonance imaging(MRI)is recommended for the diagnosis of LPLN metastasis.A LPLN-positive status on MRI is a strong risk factor for metastasis,and evaluation by MRI is important for deciding treatment strategy.LPLN dissection(LPLD)has an advantage of reducing recurrence in the lateral pelvis but also has a disadvantage of complications;therefore,LPLD may not be appropriate for cases that are less likely to have LPLN metastasis.Radiation therapy(RT)and chemoradiation therapy(CRT)have limited effects in cases with suspected LPLN metastasis,but a combination of preoperative CRT and LPLD may improve the treatment outcome.Thus,RT and CRT plus selective LPLD may be a rational strategy to omit unnecessary LPLD and produce a favorable treatment outcome.

关键词： Diagnosis Treatment Rectal cancer Lateral pelvic lymph node metastasis Lateral pelvic lymph node dissection Radiotherapy

Position Verification of the RADPOS 4-D <i>In-Vivo</i>Dosimetry System

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International Journal of Medical Physics, Clinical Engineering and Radiation Oncology 2015年第4期4卷 318-325页

作者： ryosuke Kohno Hidenori yamaguchi Kana Motegi Fumiya Tanaka Tsunemichi Akita Yuki Nagata Kenji Hotta Tomoko Miyagishi Shie Nishioka Takeshi Dohmae Tetsuo Akimoto Particle Therapy Division National Cancer Center Hospital East Kashiwa Japan Graduate School of Pure and Applied Sciences University of Tsukuba Tsukuba Japan

The accuracy of the position measurements obtained by the radiation positioning system (RADPOS) was evaluated under static and dynamic conditions. In the static verifications, the RADPOS was fixed to the treatment couch in a photon treatment room and a proton treatment room, and was translocated with the treatment couch in x, y and z directions. Because the presence of magnetic and/or electrically conductive materials can cause a systematic shift in the measured position by distorting the RADPOS transmitted field, the effect of metals on the performance of the positioning system was also investigated. Dynamic verification was performed using the couch drive and a dynamic anthropomorphic thorax phantom. We thus confirmed the utility of RADPOS as a position sensor to perform in vivo dosimetry.

关键词： RADPOS MOSFET In-Vivo Dosimetry Position Sensor Photon Therapy Proton Beam Therapy

Current state of practice for colonic diverticular bleeding in 37 hospitals in Japan: A multicenter questionnaire study

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World Journal of Gastrointestinal Endoscopy 2016年第20期8卷 785-794页

作者： Ryota Niikura Naoyoshi Nagata Hisashi Doyama ryosuke Ota Naoki Ishii Katsuhiro Mabe Tsutomu Nishida Takuto Hikichi Kazuki Sumiyama Jun Nishikawa Toshio Uraoka Shu Kiyotoki Mitsuhiro Fujishiro Kazuhiko Koike Department of Gastroenterology Graduate School of Medicinethe University of Tokyo Bunkyo-ku Tokyo 113-8655 Japan Department of Gastroenterology and Hepatology National Center for Global Health and MedicineShinjuku-ku Tokyo 162-8655 Japan Department of Gastroenterology Ishikawa Prefectural Central Hospital Kanazawa-shiIshikawa 920-8201 Japan Department of Gastroenterology St. Luke’s International Hospital Chuo-ku Tokyo 104-8560 Japan Division of Endoscopy Hokkaido University Hospital Kita-ku Sapporo 060-0808 Hokkaido Japan Department of Gastroenterology National Hospital Organization Hakodate Hospital KawaharachouHakodate-shi 041-0844 Hokkaido Japan Department of Gastroenterology Toyonaka Municipal Hospital Toyonaka-shi Osaka 560-0055 Japan Department of Endoscopy Fukushima Medical University Hospital Fukushima-shi Fukushima 960-1295 Japan Department of Endoscopy the Jikei University School of Medicine Minato-ku Tokyo 105-8471Japan Department of Clinical Laboratory Science Yamaguchi University Graduate School of Medicine Ube-shiYamaguchi 755-0046 Japan Department of Gastroenterology National Hospital Organization Tokyo Medical Center Meguro-ku Tokyo 150-0021 Japan Department of Gastroenterology Shuto General Hospital Yanai-shi Yamaguchi 742-0032 Japan Endoscopy and Endoscopic Surgery the University of Tokyo Hospital Bunkyo-ku Tokyo 113-8655 Japan

AIM To clarify the current state of practice for colonic diverticular bleeding(CDB) in Japan.METHODS We conducted multicenter questionnaire surveys of the practice for CDB including clinical settings(8 questions),diagnoses(8 questions),treatments(7 questions),and outcomes(4 questions) in 37 hospitals across Japan.The answers were compared between hospitals with high and low number of inpatient beds to investigate which factor influenced the answers.RESULTS Endoscopists at all 37 hospitals answered the questions,and the mean number of endoscopists at these hospitals was 12.7.Of all the hospitals,computed tomography was performed before colonoscopy in 67% of the hospitals.The rate of bowel preparation was 46.0%.Early colonoscopy was performed within 24 h in 43.2% of the hospitals.Of the hospitals,83.8% performed clipping as first-line endoscopic therapy.More than half of the hospitals experienced less than 20% rebleeding events after endoscopic hemostasis.No significant difference was observed in the annual number of patients hospitalized for CDB between high-(≥700 beds) and low-volume hospitals.More emergency visits(P=0.012) and endoscopists(P=0.015),and less frequent participation of nursing staff in early colonoscopy(P=0.045) were observed in the high-volume hospitals.CONCLUSION Some practices unique to Japan were found,such as performing computed tomography before colonoscopy,no bowel preparation,and clipping as first-line therapy.Although,the number of staff differed,the practices for CDB were common irrespective of hospital size.

关键词： colonic diverticular hemorrhage lower gastrointestinal bleeding computed tomography endoscopy bowel preparation