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Featured researches published by Naoya Ishibashi.


CardioVascular and Interventional Radiology | 2010

A Case of Lipiduria After Arterial Embolization for Renal Angiomyolipomas

Naoya Ishibashi; Takao Mochizuki; Hiroshi Tanaka; Yasuhiro Okada; Masaki Kobayashi; Motoichiro Takahashi

We report the case of a 31-year-old woman who suffered lipiduria after selective transcatheter arterial embolization for renal angiomyolipoma (AML). Computed tomography confirmed cystic liquefactive necrosis with fat-fluid level in AML. Although the process by which AML fat tissue excretion occurs is not clear, we speculated that the infarcted AML was connected to the urinary collection duct system and subsequently its adipose component was excreted into the urine.


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.


International Journal of Hematology | 2016

Radiation therapy for primary breast lymphoma in male gynecomastia: a rare case report and review of the literature

Naoya Ishibashi; Masaharu Hata; Takao Mochizuki; Kogi Ogawa; Hiroaki Sugiura; Yoshinori Takekawa; Toshiya Maebayashi; Takuya Aizawa; Masakuni Sakaguchi; Osamu Abe

Primary breast lymphoma is a rare type of non-Hodgkin lymphoma and usually affects women, although a few cases have been reported in men. Chemotherapy and radiation therapy, or a combination of both, are frequently administered for treatment of primary breast lymphoma, as local control by surgical resection is poor. No standard therapy has been established, and the optimal radiation dose and irradiation field for male patients are unknown. The present report describes a 75-year-old man with bilateral cirrhosis-induced gynecomastia who was diagnosed with primary breast lymphoma; specifically, diffuse large B-cell lymphoma. Because of his hepatic dysfunction, he was treated with radiation therapy alone. Radiation therapy was followed by eight cycles of rituximab monotherapy. Clinical response was good, with no signs of relapse. Clinicians may benefit from knowledge regarding effective treatment of primary breast lymphoma in male patients, which has been rarely reported owing to the low incidence of this condition. The outcome in the present case may help to establish effective treatment guidelines in similar cases.


Journal of Pediatric Hematology Oncology | 2015

Successful Pregnancy and Delivery After Radiation With Ovarian Shielding for Acute Lymphocytic Leukemia Before Menarche.

Naoya Ishibashi; Toshiya Maebayashi; Takuya Aizawa; Masakuni Sakaguchi; Osamu Abe; Tsutomu Saito; Yoshiaki Tanaka; Motoaki Chin; Hideo Mugishima

Total body irradiation is performed as a preconditioning regimen to inhibit graft-versus-host disease after bone marrow transplantation and to eradicate remaining tumor cells. However, these regimens result in delayed secondary sex characteristics and failure of ovarian function recovery, leading to amenorrhea and infertility. Herein, we report a case of an 11-year-old girl diagnosed with acute lymphocytic leukemia who received induction chemotherapy and prophylactic cranial irradiation. For bone marrow transplantation, she received total body irradiation of 12 Gy with uterine and ovarian shielding at 13 years of age. The patient remained in remission and menarche began at 14 years of age. At 23, she became pregnant and delivered a baby naturally with no abnormalities.


Journal of Radiation Research | 2018

National survey of myeloablative total body irradiation prior to hematopoietic stem cell transplantation in Japan: survey of the Japanese Radiation Oncology Study Group (JROSG)

Naoya Ishibashi; Toshinori Soejima; Hiroki Kawaguchi; Takeshi Akiba; Masatoshi Hasegawa; Kouichi Isobe; Hitoshi Ito; Michiko Imai; Yasuo Ejima; Masaharu Hata; Keisuke Sasai; Emiko Shimoda; Toshiya Maebayashi; Masahiko Oguchi; Tetsuo Akimoto

Abstract A myeloablative regimen that includes total-body irradiation (TBI) before hematopoietic stem cell transplantation results in higher patient survival rates than achieved with regimens without TBI. The TBI protocol, however, varies between institutions. In October 2015, the Japanese Radiation Oncology Study Group initiated a national survey of myeloablative TBI (covering 2010–2014). Among the 186 Japanese institutions performing TBI, 90 (48%) responded. The 82 institutions that had performed myeloablative TBI during this period treated 2698 patients with malignant disease [leukemia (2082 patients, 77.2%), malignant lymphoma (378, 14%)] and 37 with non-malignant disease [severe aplastic anemia (20, 54%), inborn errors of metabolism (5, 14%)]. A linear accelerator was used at all institutions. The institutions were divided into 41 large and 41 small institutions based on the median number of patients. The long source–surface distance technique was the method of choice in the 34 institutions (82.9%) and the moving-couch technique in the 7 (17.1%) in the large institutions. The schedules most routinely used by the participating institutions consisted of 12 Gy/6 fractions/3 days (26 institutions, 63.5%) in the large institutions. The dose rate varied from 5 to 26 cGy/min. The lungs and lenses were routinely shielded in 23 large institutions (56.1%), and only the lungs in 9 large institutions (21.9%). At lung-shielding institutions, the most frequent maximum acceptable total dose for the lungs was 8 Gy (19 institutions, 27.5%). Our results reveal considerable differences in the TBI methods used by Japanese institutions and thus the challenges in designing multicenter randomized trials based on TBI.


Oncology Letters | 2017

Treatment outcomes of concurrent hyperthermia and chemoradiotherapy for pancreatic cancer: Insights into the significance of hyperthermia treatment

Toshiya Maebayashi; Naoya Ishibashi; Takuya Aizawa; Masakuni Sakaguchi; Tsutomu Sato; Jiro Kawamori; Yoshiaki Tanaka

Patients with locally advanced unresectable pancreatic cancer (LAUPC) have a poor prognosis. In addition their quality of life impaired by cancer pain and biliary tract infections. Therefore, multimodality therapy and selection of optimal treatment methods are essential for achieving prolonged survival. The present study investigated the significance of using hyperthermia concurrently with multimodality therapy to improve treatment outcomes in patients with LAUPC. In total, 13 patients receiving concurrent hyperthermia and chemoradiotherapy (HCR) or chemoradiotherapy (CR) alone for LAUPC between 2002 and 2013 were analyzed retrospectively. Of the 13 patients, 5 received concurrent HCR and 8 received CR. The chemotherapy regimens were 5-fluorouracil (5-FU) in 5 patients and gemcitabine hydrochloride (GEM) in the other 8. Patients who gave consent for hyperthermia treatment received GEM plus CR. The median overall survival period for all patients was 12 months and the 1-year survival rate was 55%; the corresponding values were 12 months and 57% in the GEM CR group, and 15 months and 80% in the HCR group. Univariate analyses was perfomed to identify factors predicting recurrence after treatment. The potential prognostic factors analyzed were: Age, sex, performance status, location, tumor size, the tumor marker CA 19-9, total radiation dose, chemotherapy and hyperthermia. Univariate analysis for factors associated with outcomes revealed a significant difference favoring the HCR group [relative risk=15.97 (95% confidence interval: 12.87-19.83) P=0.021]. In conclusion, hyperthermia merits active recommendation to pancreatic cancer patients who have a positive attitude toward this treatment and whose performance status is satisfactory.


Clinical Imaging | 2017

Vaginal tumor–vesical fistula detected by dynamic fluorodeoxyglucose-positron emission tomography/computed tomography: A case report

Naoya Ishibashi; Toshiya Maebayashi; Takuya Aizawa; Masakuni Sakaguchi; Yasuo Amano

Preoperative fistulas are rare in patients with bladder mucosa-invading gynecological tumors. This is the first reported case of a vesico-vaginal fistula identified using 2-deoxy-2-[fluorine-18]fluoro-d-glucose positron emission tomography/computed tomography (18F-FDG-PET/CT) in a patient with vaginal cancer. A 61-year-old woman with vaginal cancer underwent 18F-FDG-PET/CT for assessment of the mass and lymph nodes. Assessment was difficult because overlap of FDG uptake occurred on 18F-FDG-PET/CT images obtained 60min after FDG injection. However, dynamic 18F-FDG-PET/CT clearly indicated the presence of a vaginal tumor-vesical fistula. This case illustrates the usefulness of dynamic 18F-FDG-PET/CT imaging when assessing a vesico-vaginal fistula.


Translational cancer research | 2018

Synchronous organizing pneumonia after sequential three-dimensional radiotherapy for three lung metastases from hepatocellular carcinoma: a case report

Masakuni Sakaguchi; Toshiya Maebayashi; Takuya Aizawa; Naoya Ishibashi

Radiation-induced lung injury can be categorized into radiation pneumonitis (RP) and organizing pneumonia (OP). Differences between RP and OP have been reported in terms of the time to appearance, predictive factors, expression mechanism, and migration of lung infiltration. However, no author has demonstrated the time to OP appearance after sequential radiotherapy for lung tumors in the same patient. We describe woman in her 70s with lung metastases developed OP synchronously after sequential three-dimensional radiotherapy (3D-CRT). A woman in her 70s who had received 3D-CRT sequentially for three metastases in the left lung from hepatocellular carcinoma (HCC). We administer 3D-CRT for metastases in the left upper lobe. Three months after the end of 3D-CRT, there were no changes outside or inside the radiation field on chest radiographs and computed tomography (CT). We decided to administer 3D-CRT for a second time due to metastasis to the lower lobe. At 1.5 months after the end of the second 3D-CRT course, the patient presented with dry cough, at 2 months from the second radiotherapy cycle, dense pneumonic infiltrates with air bronchograms within the first and second radiation fields and outside the field was synchronously detected. A diagnosis of lung injury, most probably OP, due to radiotherapy was made. This case report draws attention to the development of synchronous OP after sequential radiotherapy and advises careful follow-up with the initiation of a second radiotherapy cycle even if OP does not appear for several months after the first radiotherapy cycle.


Translational cancer research | 2018

Radiation therapy for superficial inguinal lymph node metastases from ovarian clear cell carcinoma and associated inguinal hernia

Naoya Ishibashi; Toshiya Maebayashi; Haruna Nishimaki; Masahiro Okada

About 3% of ovarian cancer (OC) metastases reportedly involve inguinal lymph nodes, but little published data on their radiosensitivity is available. Here, we report a 53-year-old woman with clear cell OC and left inguinal, supra-inguinal and obturator lymph node metastases (LNMs), and a huge, unresectable mass of adherent inguinal nodes. After standard hysterectomy, bilateral salpingo-oophorectomy, omentectomy, and pelvic lymphadenectomy, she underwent various chemotherapy regimens over 12 months, as the inguinal mass enlarged. Radiotherapy was subsequently successful but complicated by an inguinal hernia. Combined cytoreductive surgery, inguinal metastasectomy, and radiotherapy may be appropriate for patients with OC with inguinal LNMs.

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