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Dive into the research topics where Toshiya Maebayashi is active.

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Featured researches published by Toshiya Maebayashi.


Journal of Computer Assisted Tomography | 2003

Radiologic Features of Uterine Lipoleiomyoma

Toshiya Maebayashi; Kazuo Imai; Yoshinori Takekawa; Jun Sasaki; Hitoki Otsuka; Yoshihisa Katsura; Takao Mochizuki

Rare cases of uterine lipoleiomyoma are reported with the presentation of plain film, computed tomography, and magnetic resonance imaging.


Pancreas | 2012

Long-term follow-up of nutritional status, pancreatic function, and morphological changes of the pancreatic remnant after pancreatic tumor resection in children.

Kiminobu Sugito; Takeshi Furuya; Hide Kaneda; Takayuki Masuko; Kensuke Ohashi; Mikiya Inoue; Taro Ikeda; Tsugumichi Koshinaga; Ryouichi Tomita; Toshiya Maebayashi

Objectives The objectives of the present study were to determine nutritional status, pancreatic function, and morphological changes of the pancreatic remnant after pancreatic tumor resection in children. Methods The nutritional status was evaluated by the patterns of growth. Pancreatic function was evaluated by using a questionnaire, the Bristol stool form chart, the serum levels of fasting blood glucose, and hemoglobin A1c (HbA1c). Morphological changes of the pancreatic remnant were evaluated by computed tomography, magnetic resonance image, or magnetic resonance cholangiopancreatography. Results The present study consisted of 6 patients with pancreatic tumor (5 solid pseudopapillary tumors of the pancreas and 1 pancreatoblastoma) who underwent the following operations: tumor enucleation (3), distal pancreatectomy with splenectomy (1), and pylorus-preserving pancreatoduodenectomy (PPPD [2]). The serum levels of HbA1c have been gradually elevated in 2 patients with PPPD. A significant decrease in pancreatic parenchymal thickness and dilatation of the main pancreatic duct were observed in 2 patients with PPPD. Conclusion Endocrine pancreatic insufficiency after PPPD may be explainable by obstructive pancreatitis after operation. Taking together the results of pancreatic endocrine function and morphological changes of pancreatic remnant after PPPD, tumor enucleation should be considered as surgical approach in children with pancreas head tumor whenever possible.


Abdominal Imaging | 2010

Primary leiomyosarcoma of the inferior vena cava: case report

Mitsuhiro Narata; Yoshitaka Okuhata; Katsumi Abe; Akiko Takemoto; Toshiya Maebayashi; Satoshi Furuhashi; Motoichiro Takahashi

The patient was a 63-year-old woman with a chief complaint of blood-stained sputum. A tumor of the inferior vena cava was found on chest computed tomography (CT) and identified as a primary tumor based on multidetector CT and contrast-enhanced MR angiography. An intrapelvic tumor was also discovered. On autopsy, the two tumors were diagnosed as leiomyosarcoma and ovarian fibroma, respectively.


International Journal of Clinical Oncology | 2011

The clinical course in pediatric solid tumor patients with focal nodular hyperplasia of the liver

Kiminobu Sugito; Shota Uekusa; Hiroyuki Kawashima; Takeshi Furuya; Kensuke Ohashi; Mikiya Inoue; Taro Ikeda; Tsugumichi Koshinaga; Ryouichi Tomita; Hideo Mugishima; Toshiya Maebayashi

BackgroundFocal nodular hyperplasia (FNH) of the liver is a rare benign lesion that may be related to the vascular and hepatic damage induced by completion of tumor therapy and a reaction to localized vascular abnormality. The aim of this study was to analyze the clinical course in pediatric solid tumor patients with FNH.MethodsWe analyzed thirty-two patients with pediatric solid tumors who received multiagent chemotherapy (15 advanced neuroblastomas, 7 hepatoblastomas, 5 rhabdomyosarcomas, 2 nephroblastomas, 1 rhabdoid tumor of the kidney, 1 clear cell sarcoma of the kidney and 1 pancreatoblastoma). All of them had been previously treated at our hospital, and have been alive for over 3 years without recurrence.ResultsFNH lesions were discovered in three (9.4%) of 32 patients, and were neuroblastoma (NB) stage 4. All 3 patients received induction chemotherapy and high-dose alkylating agents, and developed grade 3 (National Cancer Institute Common Toxicity Criteria; NCI-CTC) liver dysfunction during completion of tumor therapy without veno-occlusive disease. Two of the 3 patients received the same induction chemotherapy and high doses of alkylating agents with total body irradiation for cytoreductive agents prior to peripheral blood cell transplantation. FNH lesions in both female patients who received estrogen replacement therapy after completion of tumor therapy have expanded and are increasing.ConclusionFNH appears to be a late complication of iatrogenic disease in NB stage 4 patients. The therapeutic agents for NB stage 4 and estrogen replacement therapy should be considered as risk factors for the development of FNH.


Abdominal Imaging | 2010

Characteristics of ectopic pancreas in dynamic gadolinium-enhanced MRI

Yoshitaka Okuhata; Toshiya Maebayashi; Satoshi Furuhashi; Katsumi Abe; Motoichiro Takahashi; Noriaki Kanamori; Kazuto Inoue; Tadatoshi Takayama

The characteristics of jejunal ectopic pancreas in dynamic gadolinium-enhanced magnetic resonance imaging are described in a 40-year-old man with bowel obstruction. The pre-contrast signal intensity and post-contrast enhancement pattern of ectopic pancreas are the same as those of the pancreas.


Radiotherapy and Oncology | 2014

Factors influencing survival outcome for radiotherapy for biliary tract cancer: A multicenter retrospective study

Yasuo Yoshioka; Kazuhiko Ogawa; Hirobumi Oikawa; Hiroshi Onishi; Nobue Uchida; Toshiya Maebayashi; Naoto Kanesaka; Tetsuro Tamamoto; Hirofumi Asakura; Takashi Kosugi; Kazuo Hatano; Michio Yoshimura; Kazunari Yamada; Sunao Tokumaru; Kenji Sekiguchi; Masao Kobayashi; Toshinori Soejima; Fumiaki Isohashi; Kenji Nemoto; Yasumasa Nishimura

PURPOSE To seek for the possible factors influencing overall survival (OS) with radiotherapy (RT) for biliary tract cancer. MATERIALS AND METHODS Data were collected retrospectively from RT database of 31 institutions in Japan. All patients underwent at least external beam RT. The factors influencing OS were investigated. RESULTS Data of 498 patients were analyzed. Median OS of the 212 patients who underwent surgery was significantly better than that of the 286 patients without surgery (31 vs. 15 months, p<0.001). The OS for the R0 or R1 resection group was significantly longer than that for the R2 or non-surgery group, as well as for n0 compared to n1 (all p<0.001). Chemoradiotherapy (CRT), both sequential and concurrent, resulted in a better OS than RT alone for the n1 group (31 vs. 13 months, p<0.001), and marginally better for the R0/R1 group (p=0.065; p=0.054 for concurrent CRT). However, no such benefit was observed for the R2/non-surgical patients. Multivariate analysis identified performance status, clinical stage, and surgery as significant factors. CONCLUSION Surgery, especially R0/R1 resection, seemed as the gold standard for treatment of biliary tract cancer including RT, even in the highly heterogeneous population obtained from the multicenter retrospective study. The possibility was shown that CRT yielded better survival benefit especially for n1 patients. We recommend that future prospective trials include an arm of adjuvant CRT at least for n1 and possibly R0/R1 patients.


Medical Oncology | 2010

Radiological assessment following thermoradiation therapy for primary pleural synovial sarcoma: case report

Katsumi Abe; Toshiya Maebayashi; Takashi Shizukuishi; Masakuni Sakaguchi; Satoru Furuhashi; Motoichiro Takahashi; Yoshiaki Tanaka; Akihito Uematsu; Masahiko Sugitani

Primary pleural synovial sarcoma is a rare disease with poor outcomes. Although hyperthermia therapy as part of a combined treatment regimen can offer improved local tumor control, only two reports of hyperthermia therapy for synovial sarcoma have appeared in the literature, and these sarcomas were not of pleuropulmonary origin. This report of an advanced inoperable primary pleural synovial sarcoma is the first to address the use of hyperthermia therapy in combination with chemoradiotherapy for this disease, together with radiological assessment following that therapy. Computed tomography performed after thermoradiation showed a decrease in tumor size and a characteristic unenhanced low-density area in the tumor suggesting that tumor necrosis resulted from the therapy. These image findings were helpful in assessing the tumor response to thermoradiation. We believe that hyperthermia therapy combined with chemoradiotherapy should be regarded as an option for advanced primary pleural synovial sarcoma. This would give computed tomography important role in evaluating this approach.


World Journal of Surgical Oncology | 2015

Solitary pulmonary metastasis from prostate cancer with neuroendocrine differentiation: a case report and review of relevant cases from the literature

Toshiya Maebayashi; Katsumi Abe; Takuya Aizawa; Masakuni Sakaguchi; Naoya Ishibash; Shoko Fukushima; Taku Honma; Yoshiaki Kusumi; Tsuyoshi Matsui; Nozomu Kawata

BackgroundSolitary lung metastasis from prostate cancer is rare. There are few reports of such cases with neuroendocrine differentiation.Case presentationA 50-year-old man presented to our hospital with a chief complaint of dysuria. Histological examination revealed prostate cancer, which was classified as cT4 N0 M0, stage IV adenocarcinoma. Since the patient was at high risk, endocrine and radiation therapies were started. One year after starting radiation therapy, the patient developed bloody sputum. Chest radiography revealed a nodular shadow in his left lung (S5). Although 18-fluoro-2-deoxyglucose positron emission tomography revealed abnormal accumulation in the lesion, the cytological diagnosis was class IIIa, which did not yield a definitive diagnosis. Given that prostate specific antigen (PSA) was not elevated, a primary lung tumor was suspected, and thoracoscopic segmental resection of the lung was performed with lymph node dissection. The final pathological diagnosis was solitary lung metastasis from prostate cancer with neuroendocrine differentiation and mediastinal lymph node metastasis. The specimen showed a mixed pattern of conventional prostatic and neuroendocrine carcinomas.ConclusionWe herein report a case with neuroendocrine differentiation (NED), along with a review of the relevant literature, including histopathological findings. According to previous case reports, some patients with solitary lung metastasis from prostate cancer achieved relatively good long-term survival. We consider establishing the correct diagnosis and implementing an appropriate treatment plan to be essential in prostate cancer patients with oligometastases that have the potential to be neuroendocrine (NE) tumors.


Hematology | 2015

Myelosuppression toxicity of palliative splenic irradiation in myelofibrosis and malignant lymphoma

Naoya Ishibashi; Toshiya Maebayashi; Takuya Aizawa; Masakuni Sakaguchi; Osamu Abe; Tsutomu Saito; Yoshiaki Tanaka

Abstract Objectives Distinctive splenomegaly resulting from extramedullary hematopoiesis and infiltration of neoplastic cells is observed in some patients with myelofibrosis (MF) or malignant lymphoma. Palliative splenic irradiation is known to be effective for such patients and is widely performed. However, little is known about the biological mechanism of palliative splenic irradiation. Various reports have focused on irradiation doses, in terms of efficacy and safety. We examined the toxicity of myelosuppression and the timing of the platelet, white blood cell, and red blood cell count nadirs within 3 months after the start of irradiation in a total of eight patients with MF or malignant lymphoma, all of whom underwent palliative splenic irradiation at our hospital between 2004 and 2013. Methods Five patients with idiopathic MF and three patients with non-Hodgkins lymphoma (NHL) treated with splenic irradiation between 2004 and 2013. Of the three patients with NHL, two had diffuse large B-cell lymphoma and one had mantle cell lymphoma. There were four male and four female patients, with median age of 61 years (range, 51–73). Patients with MF received irradiation at 20–100 cGy per fraction dose; four patients received irradiation five times a week and one patient received irradiation three times a week. In three of these patients, the irradiation dose was gradually increased while observing for hematotoxicity. Patients with NHL received irradiation at a fraction dose of 150–200 cGy, and all received irradiation five times a week. Irradiation was terminated when we judged symptoms to be alleviated, splenomegaly reduced, or efficacy to be poor. With regard to the total irradiation dose, 175, 320, 400, 600, and 640 cGy were given to one MF patient each, and 1050 and 3000 cGy were given to one and two NHL patients, respectively. Results Symptoms diminished or disappeared in five of the six symptomatic patients (83%). A reduction in the size of the spleen was confirmed in five of six patients (83%) with splenomegaly. For MF, the platelet count nadir was observed at week 3 in two patients, week 5 in two, and week 6 in one patient. For NHL, it was observed at week 1 in one patient, week 4 in one, and week 9 in one patient. For MF, the white blood cell count nadir was observed in at week 2 in one patient, week 3 in two, and week 5 in two patients. For NHL, it was observed at week 1 in one patient and week 4 in two patients. For MF, the red blood cell count nadir was observed at week 1 in two patients, week 3 in one, week 7 in one, and week 8 in one patient. For NHL patients, it was observed at week 1 in one patient, week 4 in one, and week 9 in one patient. Discussion There was a trend for the nadir to be steeper in patients with MF than in those with NHL. With regard to the total dose, symptoms diminished at the minimum dose of 175 cGy in MF patients, whereas the maximum dose of 3000 cGy was not effective in NHL patients. These observations suggest that a splenic lesion in NHL patients may be the primary site of neoplastic cell infiltration and that extramedullary hematopoiesis may not necessarily occur in the spleen. Conclusion Although palliative irradiation of splenic lesions in patients with MF or NHL is safe and effective, optimal irradiation doses may differ for MF and NHL. More cases need to be accumulated to elucidate these differences.


Journal of Digital Imaging | 2011

Data Management Solution for Large-Volume Computed Tomography in an Existing Picture Archiving and Communication System (PACS)

Takashi Yoshinobu; Katsumi Abe; Yasuo Sasaki; Makiko Tabei; Seiji Tanaka; Motoichiro Takahashi; Satoru Furuhashi; Ikue Tanaka; Takashi Shizukuishi; Takuya Aizawa; Toshiya Maebayashi; Masakuni Sakaguchi; Yoshitaka Okuhata; Junko Kikuta; Naoya Ishibashi

Multidetector row computed tomography (MDCT) creates massive amounts of data, which can overload a picture archiving and communication system (PACS). To solve this problem, we designed a new data storage and image interpretation system in an existing PACS. Two MDCT image datasets, a thick- and a thin-section dataset, and a single-detector CT thick-section dataset were reconstructed. The thin-section dataset was archived in existing PACS disk space reserved for temporary storage, and the system overwrote the source data to preserve available disk space. The thick-section datasets were archived permanently. Multiplanar reformation (MPR) images were reconstructed from the stored thin-section datasets on the PACS workstation. In regular interpretations by eight radiologists during the same week, the volume of images and the times taken for interpretation of thick-section images with (246 CT examinations) or without (170 CT examinations) thin-section images were recorded, and the diagnostic usefulness of the thin-section images was evaluated. Thin-section datasets and MPR images were used in 79% and 18% of cases, respectively. The radiologists’ assessments of this system were useful, though the volume of images and times taken to archive, retrieve, and interpret thick-section images together with thin-section images were significantly greater than the times taken without thin-section images. The limitations were compensated for by the usefulness of thin-section images. This data storage and image interpretation system improves the storage and availability of the thin-section datasets of MDCT and can prevent overloading problems in an existing PACS for the moment.

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