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Featured researches published by S. Takemoto.


International Journal of Radiation Oncology Biology Physics | 2012

Progression of Non-Small-Cell Lung Cancer During the Interval Before Stereotactic Body Radiotherapy

T. Murai; Yuta Shibamoto; F. Baba; Chisa Hashizume; Yoshimasa Mori; Shiho Ayakawa; Tatsuya Kawai; S. Takemoto; Chikao Sugie; Hiroyuki Ogino

PURPOSE To investigate the relationship between waiting time (WT) and disease progression in patients undergoing stereotactic body radiotherapy (SBRT) for lung adenocarcinoma (AD) or squamous cell carcinoma (SQ). METHODS AND MATERIALS 201 patients with Stage I AD or SQ undergoing SBRT between January 2004 and June 2010 were analyzed. The WT was defined as the interval between diagnostic computed tomography before referral and computed tomography for treatment planning or positioning before SBRT. Tumor size was measured on the slice of the longest tumor diameter, and tumor volume was calculated from the longest diameter and the diameter perpendicular to it. Changes in tumor volume and TNM stage progression were evaluated, and volume doubling time (VDT) was estimated. RESULTS The median WT was 42 days (range, 5-323 days). There was a correlation between WT and rate of increase in volume in both AD and SQ. The median VDTs of AD and SQ were 170 and 93 days, respectively. Thirty-six tumors (23%) did not show volume increase during WTs >25 days. In 41 patients waiting for ≤4 weeks, no patient showed T stage progression, whereas in 25 of 120 (21%) patients waiting for >4 weeks, T stage progressed from T1 to T2 (p = 0.001). In 10 of 110 (9.1%) T1 ADs and 15 of 51 (29%) T1 SQs, T stage progressed (p = 0.002). N stage and M stage progressions were not observed. CONCLUSION Generally, a WT of ≤4 weeks seems to be acceptable. The WT seems to be more important in SQ than in AD.


Radiation Oncology | 2012

Treatment and prognosis of patients with late rectal bleeding after intensity-modulated radiation therapy for prostate cancer.

S. Takemoto; Yuta Shibamoto; Shiho Ayakawa; Aiko Nagai; A. Hayashi; Hiroyuki Ogino; F. Baba; T. Yanagi; Chikao Sugie; Hiromi Kataoka; Mikio Mimura

BackgroundRadiation proctitis after intensity-modulated radiation therapy (IMRT) differs from that seen after pelvic irradiation in that this adverse event is a result of high-dose radiation to a very small area in the rectum. We evaluated the results of treatment for hemorrhagic proctitis after IMRT for prostate cancer.MethodsBetween November 2004 and February 2010, 403 patients with prostate cancer were treated with IMRT at 2 institutions. Among these patients, 64 patients who developed late rectal bleeding were evaluated. Forty patients had received IMRT using a linear accelerator and 24 by tomotherapy. Their median age was 72 years. Each patient was assessed clinically and/or endoscopically. Depending on the severity, steroid suppositories or enemas were administered up to twice daily and Argon plasma coagulation (APC) was performed up to 3 times. Response to treatment was evaluated using the Rectal Bleeding Score (RBS), which is the sum of Frequency Score (graded from 1 to 3 by frequency of bleeding) and Amount Score (graded from 1 to 3 by amount of bleeding). Stoppage of bleeding over 3 months was scored as RBS 1.ResultsThe median follow-up period for treatment of rectal bleeding was 35 months (range, 12–69 months). Grade of bleeding was 1 in 31 patients, 2 in 26, and 3 in 7. Nineteen of 45 patients (42%) observed without treatment showed improvement and bleeding stopped in 17 (38%), although mean RBS did not change significantly. Eighteen of 29 patients (62%) treated with steroid suppositories or enemas showed improvement (mean RBS, from 4.1 ± 1.0 to 3.0 ± 1.8, p = 0.003) and bleeding stopped in 9 (31%). One patient treated with steroid enema 0.5-2 times a day for 12 months developed septic shock and died of multiple organ failure. All 12 patients treated with APC showed improvement (mean RBS, 4.7 ± 1.2 to 2.3 ± 1.4, p < 0.001) and bleeding stopped in 5 (42%).ConclusionsAfter adequate periods of observation, steroid suppositories/enemas are expected to be effective. However, short duration of administration with appropriate dosage should be appropriate. Even when patients have no response to pharmacotherapy, APC is effective.


Journal of Radiation Research | 2014

Toxicity and efficacy of three dose-fractionation regimens of intensity-modulated radiation therapy for localized prostate cancer

Y. Manabe; Yuta Shibamoto; Chikao Sugie; F. Baba; Shiho Ayakawa; Aiko Nagai; S. Takemoto; A. Hayashi; Noriyasu Kawai; Mitsuru Takeuchi; Satoshi Ishikura; Kenjiro Kohri; T. Yanagi

Outcomes of three protocols of intensity-modulated radiation therapy (IMRT) for localized prostate cancer were evaluated. A total of 259 patients treated with 5-field IMRT between 2005 and 2011 were analyzed. First, 74 patients were treated with a daily fraction of 2.0 Gy to a total of 74 Gy (low risk) or 78 Gy (intermediate or high risk). Then, 101 patients were treated with a 2.1-Gy daily fraction to 73.5 or 77.7 Gy. More recently, 84 patients were treated with a 2.2-Gy fraction to 72.6 or 74.8 Gy. The median patient age was 70 years (range, 54–82) and the follow-up period for living patients was 47 months (range, 18–97). Androgen deprivation therapy was given according to patient risk. The overall and biochemical failure-free survival rates were, respectively, 96 and 82% at 6 years in the 2.0-Gy group, 99 and 96% at 4 years in the 2.1-Gy group, and 99 and 96% at 2 years in the 2.2-Gy group. The biochemical failure-free rate for high-risk patients in all groups was 89% at 4 years. Incidences of Grade ≥2 acute genitourinary toxicities were 9.5% in the 2.0-Gy group, 18% in the 2.1-Gy group, and 15% in the 2.2-Gy group (P = 0.29). Cumulative incidences of Grade ≥2 late gastrointestinal toxicity were 13% in the 2.0-Gy group at 6 years, 12% in the 2.1-Gy group at 4 years, and 3.7% in the 2.2-Gy group at 2 years (P = 0.23). So far, this stepwise shortening of treatment periods seems to be successful.


Journal of Neurosurgery | 2017

Robustness of the neurological prognostic score in brain metastasis patients treated with Gamma Knife radiosurgery

Toru Serizawa; Yoshinori Higuchi; Osamu Nagano; Shinji Matsuda; Kyoko Aoyagi; Junichi Ono; Naokatsu Saeki; Yasuo Iwadate; Tatsuo Hirai; S. Takemoto; Yuta Shibamoto

OBJECTIVE The neurological prognostic score (NPS) was recently proposed as a means for predicting neurological outcomes, such as the preservation of neurological function and the prevention of neurological death, in brain metastasis patients treated with Gamma Knife radiosurgery (GKRS). NPS consists of 2 groups: Group A patients were expected to have better neurological outcomes, and Group B patients were expected to have poorer outcomes. NPS robustness was tested in various situations. METHODS In total, 3040 patients with brain metastases that were treated with GKRS were analyzed. The cumulative incidence of the loss of neurological function independence (i.e., neurological deterioration) was estimated using competing risk analysis, and NPS was compared between Groups A and B by employing Grays model. NPS was tested to determine if it can be applied to 5 cancer categories-non-small cell lung cancer, small cell lung cancer, gastrointestinal tract cancer, breast cancer, and other cancers-as well as if it can be incorporated into the 5 major grading systems: recursive partitioning analysis (RPA), score index for stereotactic radiosurgery (SIR), basic score for brain metastases (BSBM), graded prognostic assessment (GPA), and modified-RPA (M-RPA). RESULTS There were 2263 patients in NPS Group A and 777 patients in Group B. Neurological deterioration was observed in 586 patients (19.2%). The cumulative incidences of neurological deterioration were 9.5% versus 21.0%, 14.1% versus 25.4%, and 17.6% versus 27.8% in NPS Groups A and B at 1, 2, and 5 years, respectively. Significant differences were detected between the NPS groups in all cancer categories. There were significant differences between NPS Groups A and B for all classes in terms of the BSBM, GPA, and M-RPA systems, but the differences failed to reach statistical significance in terms of RPA Class I and SIR Class 0 to 3. CONCLUSIONS The NPS was verified as being highly applicable to all cancer categories and almost all classes for the 5 grading systems in terms of neurological function independence. This NPS system appears to be quite robust in various situations for brain metastasis patients treated with GKRS.


Journal of Radiation Research | 2014

Adjuvant radiotherapy after prostatectomy for prostate cancer in Japan: a multi-institutional survey study of the JROSG

Manabu Aoki; Takashi Mizowaki; Tetsuo Akimoto; Katsumasa Nakamura; Yasuo Ejima; Keiichi Jingu; Yoshifumi Tamai; Nobuaki Nakajima; S. Takemoto; Masaki Kokubo; Hiroyuki Katoh

In Japan, the use of adjuvant radiotherapy after prostatectomy for prostate cancer has not increased compared with the use of salvage radiotherapy. We retrospectively evaluated the outcome of adjuvant radiotherapy together with prognostic factors of outcome in Japan. Between 2005 and 2007, a total of 87 patients were referred for adjuvant radiotherapy in 23 institutions [median age: 64 years (54–77 years), median initial prostate-specific antigen: 11.0 ng/ml (2.9–284 ng/ml), Gleason score (GS): 6, 7, 8, 9, 10 = 13.8, 35.6, 23.0, 27.6, 0%, respectively]. Rates of positive marginal status, seminal vesicle invasion (SVI) and extra-prostatic extension (EPE) were 74%, 26% and 64%, respectively. Median post-operative PSA nadir: 0.167 ng/ml (0–2.51 ng/ml). Median time from surgery to radiotherapy was 3 months (1–6 months). A total dose of ≥60 Gy and <65 Gy was administered to 69% of patients. The median follow-up time was 62 months. The 3- and 5-year biochemical relapse-free survival (bRFS) rates for all patients were 66.5% and 57.1%, respectively. The GS and marginal status (P = 0.019), GS and SVI (P = 0.001), marginal status and EPE (P = 0.017), type of hormonal therapy and total dose (P = 0.026) were significantly related. The 5-year bRFS rate was significantly higher in SVI-negative patients than SVI-positive patients (P = 0.001), and significantly higher in patients with post-operative PSA nadir ≤0.2 than in patients with post-operative PSA nadir >0.2 (P = 0.02), and tended to be more favorable after radiotherapy ≤3 months from surgery than >3 months from surgery (P = 0.069). Multivariate analysis identified SVI and post-operative PSA nadir as independent prognostic factors for bRFS (P = 0.001 and 0.018, respectively).


Japanese Journal of Clinical Oncology | 2014

Patterns of practice in the radiation therapy for bladder cancer: survey of the Japanese Radiation Oncology Study Group (JROSG).

Toshiya Maebayashi; Hitoshi Ishikawa; Atsunori Yorozu; Daisaku Yoshida; Hiroyuki Katoh; Kenji Nemoto; Shunichi Ishihara; S. Takemoto; Naoya Ishibashi; Sunao Tokumaru; Tetsuo Akimoto

OBJECTIVE To retrospectively analyze the clinical outcomes of radiation therapy with or without chemotherapy for bladder cancer in Japan. METHODS A questionnaire-based survey of patients with pathologically proven bladder cancer treated by definitive radiation therapy between 2002 and 2006 was conducted by the Japanese Radiation Oncology Study Group, and the clinical records of 159 patients were collected from 17 institutions. Concurrent intra-arterial chemoradiotherapy and concurrent systemic chemoradiotherapy were administered in 51 and 33 patients, respectively. RESULTS The 5-year overall survival and bladder preservation rates were 48 and 39%, respectively. Eighty-nine (56%) patients developed recurrence (bladder, 48; regional lymph nodes, 4; distant sites, 41). The results of multivariate analysis revealed that adoption of chemotherapy was the only significant prognostic factor for overall survival (relative risk = 0.615 [95% confidence interval: 0.439-0.862], P = 0.005). The type of chemotherapy administered did not significantly affect the local control or overall survival rates. The actuarial 5-year overall survival rates and bladder preservation in the radiation therapy combined with intra-arterial chemotherapy group were 64 and 58%, respectively, and the corresponding rates in the radiation therapy combined with systemic chemotherapy group were 67 and 42%, respectively. CONCLUSIONS The results of this survey revealed the current status of practice of radiation therapy for bladder cancer in Japan. A multi-institutional prospective study is needed based on the results of this study to determine the optimal radiotherapeutic approach, including the need for concurrent chemotherapy and the appropriate chemotherapy regimen for invasive bladder cancer.


International Journal of Radiation Oncology Biology Physics | 2011

Helical Tomotherapy with a 2.2-Gy Daily Fraction and Dose Reduction for the Rectum for Localized Prostate Cancer

Shiho Ayakawa; Yuta Shibamoto; Chikao Sugie; Mikio Mimura; K. Komai; Aiko Nagai; S. Takemoto; Y. Manabe; K. Uchiyama; R. Takenaka


International Journal of Radiation Oncology Biology Physics | 2010

Definitive Radiotherapy for Hilar or Mediastinal Lymph Node Metastases after Stereotactic Body Radiotherapy for Stage I Non-small Cell Lung Cancer

Y. Manabe; Yuta Shibamoto; F. Baba; R. Murata; Hiroyuki Ogino; Shiho Ayakawa; K. Kosaki; T. Murai; A. Miyakawa; S. Takemoto


International Journal of Radiation Oncology Biology Physics | 2010

Treatment and Prognosis of Patients with Late Rectal Bleeding after Intensity Modulated Radiation Therapy (IMRT) for Prostate Cancer

S. Takemoto; Yuta Shibamoto; Aiko Nagai; Shiho Ayakawa; Mikio Mimura; Chikao Sugie; T. Yanagi; S. Otsuka; K. Kosaki; T. Murai


International Journal of Radiation Oncology Biology Physics | 2017

Poster ViewingDefinitive Intensity-Modulated Radiation Therapy for Super-Elderly Patients with Prostate Cancer

T. Kondo; T. Murai; Y. Manabe; Yuta Shibamoto; A. Miyakawa; Y. Ogawa; Shiho Ayakawa; S. Takemoto; Y. Yamada

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A. Miyakawa

Nagoya City University

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F. Baba

Nagoya City University

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S. Otsuka

Nagoya City University

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H. Iwata

Nagoya City University

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K. Kosaki

Nagoya City University

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T. Murai

Nagoya City University

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