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Featured researches published by Yasuo Ejima.


International Journal of Radiation Oncology Biology Physics | 2002

Angiosarcoma treated with radiotherapy: impact of tumor type and size on outcome

Ryohei Sasaki; Toshinori Soejima; Kazushi Kishi; Yoshinari Imajo; Saeko Hirota; Norihiko Kamikonya; Masao Murakami; Tetsuya Kawabe; Yasuo Ejima; Akira Matsumoto; Kazuo Sugimura

PURPOSE Angiosarcoma is a rare and highly malignant vascular neoplasm. The purpose of this study was to elucidate the tumor characteristics and evaluate the efficacy of radiotherapy (RT) for angiosarcoma. MATERIALS AND METHODS Thirty patients with angiosarcoma (20 males and 10 females, age range 4-89 years, median 66) who received RT from 1986 to 1999 were enrolled in the study. Twenty-four patients had angiosarcoma of the face and scalp (AFS), and 6 patients had angiosarcomas at other sites. AFS was classified into two categories (according to the macroscopic features): nodular AFS (14 patients) and endophytic AFS (10 patients). The median prescribed irradiation dose was 68 Gy. Surgery had been previously performed in 9 patients, and adjuvant immunotherapy using recombinant interleukin-2 (rIL-2) was combined during and after RT in 20 patients. Univariate analyses and calculation of survival by Kaplan-Meier methods were performed. RESULTS Local tumor control was obtained in 17 patients (57%). However, 7 (47%) of them developed distant metastases. The median survival time for all patients was 8 months (7 months for AFS), and the 13-year overall survival rate was 25% (20% for AFS). Twenty-one patients died of angiosarcoma, with the cause of death local failure in 7 patients, distant failure in 7, and both in 7. Tumor type and size were found to be significant prognostic factors (p = 0.004 and p = 0.007, respectively), and age, total amount of rIL-2, gender, radiation dose, and surgery were not. Six patients (4 with nodular AFS and 2 with angiosarcoma in other parts) survived >2 years. No patient with endophytic AFS survived >2 years. Ten patients (33%) died of respiratory failure secondary to pulmonary metastases. High-dose rIL-2 administration suppressed the occurrence of distant metastases (p = 0.006). Two patients developed radiation dermatitis (Radiation Therapy Oncology Group Grade 4). CONCLUSION RT, combined with complete resection or adjuvant rIL-2 immunotherapy, could be a promising treatment strategy, leading to prolonged survival in patients with angiosarcoma.


Journal of Clinical Investigation | 2015

Compensatory glutamine metabolism promotes glioblastoma resistance to mTOR inhibitor treatment

Kazuhiro Tanaka; Takashi Sasayama; Yasuhiro Irino; Kumi Takata; Hiroaki Nagashima; Naoko Satoh; Katsusuke Kyotani; Takashi Mizowaki; Taichiro Imahori; Yasuo Ejima; Kenta Masui; Beatrice Gini; Huijun Yang; Kohkichi Hosoda; Ryohei Sasaki; Paul S. Mischel; Eiji Kohmura

The mechanistic target of rapamycin (mTOR) is hyperactivated in many types of cancer, rendering it a compelling drug target; however, the impact of mTOR inhibition on metabolic reprogramming in cancer is incompletely understood. Here, by integrating metabolic and functional studies in glioblastoma multiforme (GBM) cell lines, preclinical models, and clinical samples, we demonstrate that the compensatory upregulation of glutamine metabolism promotes resistance to mTOR kinase inhibitors. Metabolomic studies in GBM cells revealed that glutaminase (GLS) and glutamate levels are elevated following mTOR kinase inhibitor treatment. Moreover, these mTOR inhibitor-dependent metabolic alterations were confirmed in a GBM xenograft model. Expression of GLS following mTOR inhibitor treatment promoted GBM survival in an α-ketoglutarate-dependent (αKG-dependent) manner. Combined genetic and/or pharmacological inhibition of mTOR kinase and GLS resulted in massive synergistic tumor cell death and growth inhibition in tumor-bearing mice. These results highlight a critical role for compensatory glutamine metabolism in promoting mTOR inhibitor resistance and suggest that rational combination therapy has the potential to suppress resistance.


International Journal of Radiation Oncology Biology Physics | 2001

Clinical significance of serum pulmonary surfactant proteins A and D for the early detection of radiation pneumonitis

Ryohei Sasaki; Toshinori Soejima; Akira Matsumoto; Tsutomu Maruta; Kazunari Yamada; Y. Ota; Tetsuya Kawabe; Hideki Nishimura; Eiro Sakai; Yasuo Ejima; Kazuro Sugimura

PURPOSE Radiation pneumonitis (RP) is one of the most serious complications for patients who receive thoracic irradiation. To avoid this, early diagnosis of radiation pneumonitis is extremely important. The purpose of the present study is to investigate whether serum pulmonary surfactant proteins A and D (SP-A and SP-D, respectively) could be useful markers for RP. METHODS AND MATERIALS Eighty-six patients (lung cancer: 42 [primary: 39, metastatic: 3], breast cancer: 23, esophageal cancer: 21) who underwent radiation therapy were prospectively studied. Radiation doses ranged from 30-76 Gy (median, 58 Gy). Serum SP-A and SP-D levels were evaluated sequentially by a sandwich enzyme-linked immunosorbent assay (ELISA) method before, during, and throughout the follow-up period until the development of symptomatic RP or until one year after completion of radiotherapy. Specificity of the ELISA results was confirmed by Western blot analysis. Patients symptomatic for RP were graded according to the Common Toxicity Criteria. RESULTS RP occurred in 19 patients. Serum SP-D levels of patients with RP were sequentially higher than those in patients without RP. In the monitoring, serum SP-D levels at 50-60 Gy showed greater sensitivity and positive predictive values for RP detection (74% and 68%, respectively) than SP-A (26% and 21%, respectively). Western blot analysis showed that the development of RP was due to overproduction, but not proteolysis of surfactant proteins. CONCLUSION We confirm that serum SP-A and SP-D monitoring is a practical and useful diagnostic method for the early detection of RP.


Leukemia & Lymphoma | 2006

Treatment of primary intraocular lymphoma with radiation therapy : A multi-institutional survey in Japan

Koichi Isobe; Yasuo Ejima; Sunao Tokumaru; Naoto Shikama; Gen Suzuki; Mitsuhiro Takemoto; Emiko Tsuchida; Miwako Nomura; Yuta Shibamoto; Naofumi Hayabuchi

This study evaluated the clinical features and treatment outcome of 15 patients with primary intraocular lymphoma. There were nine females, with a median age of 68 years. Thirteen patients presented with bilateral lesions and median time from the onset of symptoms to diagnosis was 12 months. All but one showed the B-cell phenotype. All patients received radiation therapy (RT) with a median of 41 Gy and 10 were administered chemotherapy as well. Three patients were treated with high-dose methotrexate and nine received prophylactic cranial irradiation (PCI) with a median of 30.6 Gy. Thirteen patients obtained a complete remission. The 2-year overall and disease free survival were 74% and 58%, respectively. Although only one patient experienced local recurrence, PCI did not prevent intracranial recurrence. One patient developed a grade 3 cognitive disturbance. It was concluded that ocular RT was effective to control primary lesions. However, some modifications are indispensable to improve outcomes.


PLOS ONE | 2014

Prognostic Value of FDG PET Imaging in Patients with Laryngeal Cancer

Kazuhiro Kitajima; Yuko Suenaga; Tomonori Kanda; D. Miyawaki; K. Yoshida; Yasuo Ejima; Ryohei Sasaki; Hirokazu Komatsu; Miki Saito; Naoki Otsuki; Ken-ichi Nibu; Naomi Kiyota; Tsutomu Minamikawa; Kazuro Sugimura

Background and Purpose To investigate the prognostic value of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in patients with laryngeal cancer. Materials and Methods The study included 51 patients of whom 30 underwent definitive radiotherapy with or without chemotherapy and 21 underwent radical surgery with or without adjuvant chemoradiation therapy. FDG uptake by both the primary lesion and the neck node was measured using the maximum standardized uptake value (SUVmax). The effects of clinicopathological factors including primary tumor SUVmax and nodal SUVmax on progression-free survival, local control, nodal progression-free survival, and distant metastasis-free survival were evaluated using the log-rank test and Cox method. Results The median duration of follow-up was 48.6 months (range 8 to 82.1 months). Univariate analysis showed that nodal SUVmax, N status, and tumor TNM stage were significantly associated with recurrence, whereas primary tumor SUVmax, age, treatment strategy and T status were not. Multivariate analysis demonstrated that only the nodal SUVmax was a significantly unfavorable factor for progression-free survival (p = 0.029, hazard ratio 0.54, 95% CI 0.38-0.87) and nodal progression-free survival (p = 0.023, hazard ratio 0.51, 95% CI 0.34-0.81). ROC curve analysis and log-rank test showed that patients with a high nodal SUVmax (≧4) had a significantly lower progression-free survival rate than those with a low SUVmax (<4; p<0.0001). Conclusions The pretreatment SUVmax of nodal disease in patients with laryngeal cancer is prognostic for recurrence.


Journal of Radiation Research | 2016

Efficacy of stereotactic body radiotherapy for hepatocellular carcinoma with portal vein tumor thrombosis/inferior vena cava tumor thrombosis: evaluation by comparison with conventional three-dimensional conformal radiotherapy

Yoshiro Matsuo; K. Yoshida; Hideki Nishimura; Yasuo Ejima; D. Miyawaki; Haruka Uezono; Takeaki Ishihara; Hiroshi Mayahara; Takumi Fukumoto; Yonson Ku; Masato Yamaguchi; Koji Sugimoto; Ryohei Sasaki

This study aimed to evaluate the efficacy of stereotactic body radiotherapy (SBRT) compared with three-dimensional conformal radiotherapy (3DCRT). Forty-three patients with portal vein tumor thrombosis (PVTT)/inferior vena cava tumor thrombosis (IVCTT) treated with SBRT (27 with CyberKnife (CK) and 16 with TrueBeam (TB)) from April 2013 to December 2014, and 54 treated with 3DCRT from June 2008 to March 2013 were evaluated. Dosimetric parameters, response to radiotherapy (RT) and survival outcomes were compared in total SBRT vs. 3DCRT, CK vs. 3DCRT and TB vs. 3DCRT, respectively. The median biologically effective dose 10 (BED10) values in total SBRT, CK, TB and 3DCRT were 73.4 Gy10, 75.0 Gy10, 60.5 Gy10 and 58.5 Gy10, respectively (P < 0.001 in total SBRT vs. 3DCRT, P < 0.001 in CK vs. 3DCRT, P = 0.004 in TB vs. 3DCRT). The tumor response rates were 67%, 70%, 62% and 46%, respectively (P = 0.04, P = 0.04, P = 0.25). The 1-year overall survival rates were 49.3%, 56.7%, 38.1% and 29.3%, respectively (P = 0.02, P = 0.02, P = 0.30), and the 1-year local progression rates were 20.4%, 21.9%, 18.8% and 43.6%, respectively (P = 0.01, P = 0.04, P = 0.10). The use of SBRT made it possible to achieve a higher BED10 compared with the use of 3DCRT. Improvements in local control and survival were achieved in the CK group and the total SBRT group. Our results suggest that SBRT may have the potential to be the standard RT technique for the treatment of PVTT/IVCTT.


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

Concomitant chemoradiotherapy for advanced squamous cell carcinoma of the temporal bone.

Hirotaka Shinomiya; Shingo Hasegawa; Daisuke Yamashita; Yasuo Ejima; Yoshida Kenji; Naoki Otsuki; Naomi Kiyota; Shunsuke Sakakibara; Tadashi Nomura; Kazunobu Hashikawa; Eiji Kohmura; Ryohei Sasaki; Ken-ichi Nibu

The purpose of this study was to analyze outcomes for the treatment of locally advanced temporal bone cancer by means of concomitant chemoradiotherapy (CCRT) with a combination of cisplatin (CDDP), 5‐fluorouracil (5‐FU), and docetaxel (TPF).


Japanese Journal of Clinical Oncology | 2015

Treatment outcomes of the patients with early glottic cancer treated with initial radiotherapy and salvaged by conservative surgery.

Aya Harada; Ryohei Sasaki; D. Miyawaki; K. Yoshida; Hideki Nishimura; Yasuo Ejima; Kazuhiro Kitajima; Miki Saito; Naoki Otsuki; Ken-ichi Nibu

OBJECTIVE This retrospective study analyzed the oncological and treatment outcomes of the patients with T1-T2N0 glottic cancer, who were treated with radiotherapy as initial treatment and salvaged by conservative surgery for radiation failure. METHODS Between May 1999 and December 2010, 115 patients with glottic laryngeal cancer were treated at Kobe University Hospital. At presentation, 54 patients had stage T1a disease, 26 had stage T1b disease and 35 had stage T2 disease. Seventy-nine patients were treated with conventional radiotherapy and 36 patients were treated with hyperfractionated radiotherapy as initial treatment. RESULTS Median duration of follow-up was 61 months. Five-year local control rates of radiotherapy were 92% in T1a, 83% in T1b and 86% in T2. Of 12 patients who developed local recurrence, larynx was successfully preserved in 3 patients by laryngomicrosurgery, 7 patients by vertical partial laryngectomy and one patient by subtotal laryngectomy. Ultimate 5-year laryngeal preservation rate and local control rate of all cases were 99 and 100%, respectively. CONCLUSIONS Present results suggest that initial treatment with radiotherapy salvaged by organ preservation surgery is an effective strategy for laryngeal preservation in the treatment of T1-T2N0 glottic laryngeal cancer.


Journal of Radiation Research | 2017

Sparing of tissue by using micro-slit-beam radiation therapy reduces neurotoxicity compared with broad-beam radiation therapy

N. Mukumoto; Masao Nakayama; Hiroaki Akasaka; Yasuyuki Shimizu; Saki Osuga; D. Miyawaki; K. Yoshida; Yasuo Ejima; Yasushi Miura; Keiji Umetani; Takeshi Kondoh; Ryohei Sasaki

Micro-slit-beam radiation therapy (MRT) using synchrotron-generated X-ray beams allows for extremely high-dose irradiation. However, the toxicity of MRT in central nervous system (CNS) use is still unknown. To gather baseline toxicological data, we evaluated mortality in normal mice following CNS-targeted MRT. Male C57BL/6 J mice were head-fixed in a stereotaxic frame. Synchrotron X-ray-beam radiation was provided by the SPring-8 BL28B2 beam-line. For MRT, radiation was delivered to groups of mice in a 10 × 12 mm unidirectional array consisting of 25-μm-wide beams spaced 100, 200 or 300 μm apart; another group of mice received the equivalent broad-beam radiation therapy (BRT) for comparison. Peak and valley dose rates of the MRT were 120 and 0.7 Gy/s, respectively. Delivered doses were 96–960 Gy for MRT, and 24–120 Gy for BRT. Mortality was monitored for 90 days post-irradiation. Brain tissue was stained using hematoxylin and eosin to evaluate neural structure. Demyelination was evaluated by Klüver–Barrera staining. The LD50 and LD100 when using MRT were 600 Gy and 720 Gy, respectively, and when using BRT they were 80 Gy and 96 Gy, respectively. In MRT, mortality decreased as the center-to-center beam spacing increased from 100 μm to 300 μm. Cortical architecture was well preserved in MRT, whereas BRT induced various degrees of cerebral hemorrhage and demyelination. MRT was able to deliver extremely high doses of radiation, while still minimizing neuronal death. The valley doses, influenced by beam spacing and irradiated dose, could represent important survival factors for MRT.


Journal of Radiation Research | 2012

Efficacy of intraoperative radiotherapy targeted to the abdominal lymph node area in patients with esophageal carcinoma

Yukihisa Tamaki; Ryohei Sasaki; Yasuo Ejima; Masakazu Ogura; Yoshiharu Negoro; Toshifumi Nakajima; Masao Murakami; Yasushi Kaji; Kazuro Sugimura

We investigated whether intraoperative radiotherapy (IORT) during curative surgery for esophageal carcinoma is useful or not. The cases of 117 patients diagnosed with thoracoabdominal esophageal carcinoma who underwent curative surgery between 1986 and 2007 were reviewed: 72 patients received IORT (IORT group) and 45 did not (non-IORT group). Upper abdominal lymphadenectomy was performed in 115 patients (98.5%). Seventy patients (59.8%) received chemotherapy and 80 patients (68.4%) received external radiotherapy. IORT encompassed the upper abdominal lymph node area. A single-fraction dose of 20–30 Gy was delivered using high-energy electrons. Median follow-up duration for patients was 7.4 years. The 5-year overall survival rate did not significantly differ between the IORT and non-IORT groups. However, the 5-year abdominal control rate was significantly higher in the IORT group (89.2%) than in the non-IORT group (72.9%; P = 0.022). We next focused on a patient subgroup with a primary lesion in the lower thoracic or abdominal esophagus or measuring >6 cm in length since this subgroup is probably at high risk of upper abdominal lymph node metastasis. Of the 117 patients, 75 belonged to this subgroup, and among them 45 received IORT. Both univariate and multivariate analysis revealed the survival rate was significantly higher in patients who received IORT than in those who did not (P = 0.033 univariate; 0.026 multivariate). There were no obvious perioperative complications solely attributed to IORT. IORT for esophageal carcinoma will likely be effective for patients with a primary lesion in the lower thoracic or abdominal esophagus, or with a long lesion.

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