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Featured researches published by Tomonari Sasaki.


Journal of Thoracic Oncology | 2011

S-1 plus cisplatin with concurrent radiotherapy for locally advanced non-small cell lung cancer: a multi-institutional phase II trial (West Japan Thoracic Oncology Group 3706).

Yukito Ichinose; Takashi Seto; Tomonari Sasaki; Takeharu Yamanaka; Isamu Okamoto; Koji Takeda; Masahiro Tanaka; Nobuyuki Katakami; Toshiyuki Sawa; Shinzoh Kudoh; Hideo Saka; Yasumasa Nishimura; Kazuhiko Nakagawa; Masahiro Fukuoka

Purpose: To evaluate the combination chemotherapy using oral antimetabolite S-1 plus cisplatin (SP) with concurrent thoracic radiotherapy (RT) followed by the consolidation SP for locally advanced non-small cell lung cancer. Patients and Methods: Patients with stage III non-small cell lung cancer, 20 to 74 years of age, and Eastern Cooperative Oncology Group performance status 0 to 1 were eligible. The concurrent phase consisted of full dose S-1 (orally at 40 mg/m2/dose twice daily, on days 1–14) and cisplatin (60 mg/m2 on day 1) repeated every 4 weeks for two cycles with RT delivered beginning on day 1 (60 Gy/30 fractions over 6 weeks). After SP-RT, patients received an additional two cycles of SP as the consolidation phase. Results: Fifty-five patients were registered between November 2006 and December 2007. Of the 50 patients for efficacy analysis, the median age was 64 years; male/female 40/10; Eastern Cooperative Oncology Group performance status 0/1, 21/29; clinical stage IIIA/IIIB 18/32; and adenocarcinoma/others 20/30. There were 42 clinical responses including one complete response with an objective response rate of 84% (95% confidence interval [CI], 71–93%). The 1- and 2-year overall survival rates were 88% (95% CI, 75–94%) and 70% (95% CI, 55–81%), respectively. The median progression-free survival was 20 months. Of the 54 patients for safety analysis, common toxicities in the concurrent phase included grade 3/4 neutropenia (26%), thrombocytopenia (9%), and grade 3 esophagitis (9%) and febrile neutropenia (9%). In one patient, grade 3 pneumonitis was observed in the consolidation phase. There were two treatment-related deaths caused by infection in the concurrent phase. Conclusions: SP-RT showed a promising efficacy against locally advanced NCSLC with acceptable toxicity.


Japanese Journal of Clinical Oncology | 2007

Radiation Therapy for Recurrent Esophageal Cancer after Surgery: Clinical Results and Prognostic Factors

Yoshiyuki Shioyama; Katsumasa Nakamura; Saiji Ohga; Satoshi Nomoto; Tomonari Sasaki; Toshihiro Yamaguchi; Takashi Toba; Tadamasa Yoshitake; Hiromi Terashima; Hiroshi Honda

OBJECTIVE To evaluate the outcome of radiotherapy for recurrent esophageal cancer after surgery and to determine the prognostic factors. METHODS From 1987 through 2002, 82 patients treated with radiotherapy for loco-regional recurrences of esophageal cancer after surgery were retrospectively reviewed. The stage at initial surgery was I in 16, II in 41, III or higher in 24 and unknown in 1. The median size of recurrent tumors was 3.5 cm in diameter. Fifty-two patients were treated with radiotherapy alone, and 30 were treated with radiotherapy combined with chemotherapy. The median total dose of external radiotherapy given was 50.4 Gy in 28 fractions. RESULTS The median survival period after recurrence was 7.0 months. The 2- and 5-year overall survival rate for all patients was 22 and 11%, respectively. In univariate analysis, the patients with performance status (PS) = 0-1, or tumor size <3.5 cm, and those treated with total dose >/=50 Gy showed a better survival outcome than each the other groups. The patients with a history of previous radiotherapy showed a poorer survival outcome in univariate analysis than each the other groups. In multivariate analysis, tumor size, PS and radiation dose were independent prognostic factors for overall survival. CONCLUSION The prognosis of patients with post-operative loco-regional recurrence of esophageal cancer is poor. However, a long-term survival may be expected by definitive radiotherapy for the patients with small-size tumors and with a good PS.


Journal of Radiation Research | 2013

Postoperative radiotherapy in patients with salivary duct carcinoma: clinical outcomes and prognostic factors

Makoto Shinoto; Yoshiyuki Shioyama; Katsumasa Nakamura; Torahiko Nakashima; Naonobu Kunitake; Yuichiro Higaki; Tomonari Sasaki; Saiji Ohga; Tadamasa Yoshitake; Kayoko Ohnishi; Kaori Asai; Hideki Hirata; Hiroshi Honda

This study sought to investigate the clinical outcome and the role of postoperative radiotherapy for patients with salivary duct carcinoma (SDC) who had undergone surgery and postoperative radiotherapy. We performed a retrospective analysis of 25 SDC patients treated between 1998 and 2011 with surgery and postoperative radiotherapy. The median prescribed dose was 60 Gy (range, 49.5–61.4 Gy). The clinical target volume (CTV) was defined as the tumor bed in four patients, the tumor bed and ipsilateral neck in 14 patients, and the tumor bed and bilateral neck in six patients. Local control (LC), disease-free survival (DFS) and overall survival (OS) were estimated using the Kaplan-Meier method, and prognostic variables were analyzed with the log-rank test. The 5-year LC, DFS and OS were 67%, 45% and 47%, respectively. Disease recurrence was found in 12 patients: seven as local, four as regional and eight as distant failure. Perineural and lymphovascular invasion was a significant prognostic factor for LC (P = 0.03). Local failure was common, and the presence of local recurrence significantly affected the OS (P < 0.05). We conclude that surgery and postoperative radiotherapy is expected to decrease the risk of local failure and contribute to good prognoses for patients with SDC. It might be advisable to have the CTV include the cranial nerves involved and the corresponding parts of the skull base in cases of pathologically positive perineural invasion.


Human Mutation | 1998

ATM MUTATIONS IN PATIENTS WITH ATAXIA TELANGIECTASIA SCREENED BY A HIERARCHICAL STRATEGY

Tomonari Sasaki; Huaize Tian; Yoji Kukita; Masakazu Inazuka; Tomoko Tahira; Takashi Imai; Masatake Yamauchi; Toshiyuki Saito; Tada-aki Hori; Tomoko Hashimoto-Tamaoki; Kenshi Komatsu; Osamu Nikaido; Kenshi Hayashi

ATM has been identified as a gene that is responsible for ataxia telangiectasia (AT), a pleiotropic disorder of autosomal recessive inheritance. While many mutations of this gene in AT patients of various ethnicities have been reported, data on Japanese patients are scarce. In this report, we present the results of a thorough survey of ATM mutations in 14 unrelated AT patients, with an emphasis on Japanese subjects. We used a hierarchical strategy in which we extensively analyzed the entire coding region of the cDNA. In the first stage, point mutations were sought by PCR‐SSCP in short patches. In the second and third stages, the products of medium‐ and long‐patch PCR, each covering the entire region, were examined by agarose gel electrophoresis to search for length changes. We found a total of 15 mutations (including 12 new) and 4 polymorphisms. Abnormal splicing of ATM was frequent among Japanese, and no hotspot was obvious, suggesting no strong founder effects in this ethnic group. Eleven patients carried either one homozygous or two compound heterozygous mutations, one patient carried only one detectable heterozygous mutation, and no mutation was found in two patients. Overall, mutations were found in at least 75% of the different ATM alleles examined. Possible reasons for the inability to detect mutations in some patients are discussed. Hum Mutat 12:186–195, 1998.


Radiation Medicine | 2007

High-dose-rate brachytherapy for previously irradiated patients with recurrent esophageal cancer

Takeshi Nonoshita; Tomonari Sasaki; Hideki Hirata; Yasushi Toh; Yoshiyuki Shioyama; Katsumasa Nakamura; Hiroshi Honda

PurposeOur objective was to assess the feasibility, efficacy, and complications of high-dose-rate (HDR) brachytherapy for patients with recurrent esophageal cancer after external radiotherapy.Materials and methodsSix patients with recurrent esophageal cancer after external radiotherapy were treated with HDR brachytherapy (Ir-192 source) from January 2003 to February 2004. The median age of the patients was 69 years. All patients had received external radiotherapy (median dose 60 Gy) before HDR brachytherapy. All patients underwent HDR brachytherapy once a week with a dose of 4 or 5 Gy per fraction in the esophageal mucosa (median total dose 20 Gy). The Kaplan-Meier method was used to calculate local control rates.ResultsThe median overall survival period was 30.0 months. Local control was observed in five patients and residual tumor in one patient. Persistent local control was observed in two patients. No patient died of esophageal cancer, and all patients survived. We observed no severe late complications related to HDR brachytherapy.ConclusionThese data suggest that HDR brachytherapy is an effective and safe treatment for patients with recurrent esophageal cancer after external radiotherapy.


International Journal of Radiation Oncology Biology Physics | 2011

Radical External Beam Radiotherapy for Clinically Localized Prostate Cancer in Japan: Changing Trends in the Patterns of Care Process Survey

Kazuhiko Ogawa; Katsumasa Nakamura; Tomonari Sasaki; Hiroshi Onishi; Masahiko Koizumi; Masayuki Araya; Nobutaka Mukumoto; Teruki Teshima; Michihide Mitsumori

PURPOSE To delineate changing trends in radical external beam radiotherapy (EBRT) for prostate cancer in Japan. METHODS AND MATERIALS Data from 841 patients with clinically localized prostate cancer treated with EBRT in the Japanese Patterns of Care Study (PCS) from 1996 to 2005 were analyzed. RESULTS Significant increases in the proportions of patients with stage T1 to T2 disease and decrease in prostate-specific antigen values were observed. Also, there were significant increases in the percentages of patients treated with radiotherapy by their own choice. Median radiation doses were 65.0 Gy and 68.4 Gy from 1996 to 1998 and from 1999 to 2001, respectively, increasing to 70 Gy from 2003 to 2005. Moreover, conformal therapy was more frequently used from 2003 to 2005 (84.9%) than from 1996 to 1998 (49.1%) and from 1999 to 2001 (50.2%). On the other hand, the percentage of patients receiving hormone therapy from 2003 to 2005 (81.1%) was almost the same as that from 1996 to 1998 (86.3%) and from 1999 to 2001 (89.7%). Compared with the PCS in the United States, patient characteristics and patterns of treatments from 2003 to 2005 have become more similar to those in the United States than those from 1996 to 1998 and those from 1999 to 2001. CONCLUSIONS This study indicates a trend toward increasing numbers of patients with early-stage disease and increasing proportions of patients treated with higher radiation doses with advanced equipment among Japanese prostate cancer patients treated with EBRT during 1996 to 2005 survey periods. Patterns of care for prostate cancer in Japan are becoming more similar to those in the United States.


American Journal of Clinical Oncology | 2005

Clinical results of radiation therapy for stage I esophageal cancer: a single institutional experience.

Yoshiyuki Shioyama; Katsumasa Nakamura; Tomonari Sasaki; Saiji Ooga; Yusuke Urashima; Masahiko Kimura; Satoru Uehara; Hiromi Terashima; Hiroshi Honda

From 1992 through 2001, 29 patients with stage I esophageal cancer were treated with radiation therapy. All patients had squamous cell carcinoma. Seventeen patients were treated with radiotherapy alone, and 12 were treated with a combination of chemotherapy and radiotherapy. Most of the chemotherapy regimens included cisplatin and/or 5-fluorouracil (5-FU). Twelve patients were treated with intracavitary irradiation (low-dose rate: 6, high-dose rate: 6) after external radiotherapy. Median fraction and total doses of external radiotherapy given were 2.0 Gy and 60.6 Gy, respectively. Median doses of intracavitary irradiation were 18 Gy/6 fractions in low-dose-rate brachytherapy and 13.5 Gy/4.5 fractions in high-dose-rate brachytherapy. The 5-year overall survival rate was 62%. The 5-year local control rate was 44%. Of the 29 patients, 9 had in-field recurrence in the esophagus and 1 had recurrence in the esophagus outside of the irradiated field. Of 9 patients with in-field local recurrence, 1 also developed mediastinal lymph node metastases and 1 had distant metastasis. Radiation therapy is an effective treatment modality for stage I esophageal cancer.


Journal of Radiation Research | 2013

Prediction of outcome with FDG-PET in definitive chemoradiotherapy for esophageal cancer

Kazushige Atsumi; Katsumasa Nakamura; Koichiro Abe; Masakazu Hirakawa; Yoshiyuki Shioyama; Tomonari Sasaki; Shingo Baba; Takuro Isoda; Saiji Ohga; Tadamasa Yoshitake; Makoto Shinoto; Kaori Asai; Hiroshi Honda

The purpose of this study was to assess the efficacy of 18F-fluoro-2-deoxy-glucose uptake positron emission tomography (FDG-PET) for the prediction of outcome in definitive chemoradiotherapy (CRT) for esophageal cancer. We enrolled 56 patients with esophageal cancer treated with definitive CRT and examined by FDG-PET before treatment. We examined the correlation of the maximum standardized uptake value (SUVmax) in FDG-PET of the primary tumor with overall survival (OS), progression-free survival (PFS), local control (LC) and response of the primary tumor. After definitive CRT, 30 patients had a clinical complete response (CR), making the CR rate 54%. For all 56 patients, the 2-year OS rate, PFS rate and LC rates were 64%, 38% and 51%, respectively. We divided the patients into two groups according to SUVmax: SUVmax < 10 (low-SUV) and ≥10 (high-SUV). The 2-year OS rates in the low- and high-SUV groups were 100% and 41%, the PFS rates were 73% and 19%, the LC rates were 71% and 39%, and the CR rates were 100% and 32%, respectively. A univariate analysis revealed significant differences between the low- and high-SUV group in OS, PFS, LC and response (P = 0.0005, 0.0002, 0.048, and <0.0001, respectively). SUVmax and T stage were significantly associated with OS, PFS, LC and response. A multivariate analysis showed significant differences between the SUVmax <10 and ≥10 groups in overall survival and response (P < 0.05). Our result suggests that the SUVmax in FDG-PET of the primary tumor before treatment may have prognostic value for esophageal cancer.


Japanese Journal of Clinical Oncology | 2013

Treatment Outcome of High-dose-rate Interstitial Radiation Therapy for Patients with Stage I and II Mobile Tongue Cancer

Keiji Matsumoto; Tomonari Sasaki; Yoshiyuki Shioyama; Katsumasa Nakamura; Kazushige Atsumi; Takeshi Nonoshita; Saiji Ooga; Tadamasa Yoshitake; Satoru Uehara; Hideki Hirata; Hiroshi Honda

OBJECTIVES The aim of the study was to investigate the outcomes of high-dose-rate interstitial radiation therapy for patients with Stage I and II mobile tongue cancer retrospectively. METHODS Sixty-seven patients with Stage I and II mobile tongue cancer were treated with high-dose-rate interstitial radiation therapy, with or without external beam radiation therapy, between 1997 and 2007. The median dose of interstitial radiation therapy was 50 Gy in 10 fractions over 6 days. Thirty-five patients received external beam radiation therapy before interstitial radiation therapy. The median dose of external beam radiation therapy was 20 Gy delivered with single-lateral or bilateral fields, including the primary tumor site and upper jugular lymph nodes. Thirty-seven patients received concurrent chemotherapy, including carboplatin, cisplatin, fluorouracil or tegafur, gimeracil and oteracil (TS-1) systemically or with intra-arterial injection. Thirty-three patients received intratumoral injection of bleomycin before catheter insertion. The median follow-up time was 58.6 months (range 15.1-102.4 months). RESULTS The 5-year overall, cause-specific, progression-free survival rate and local control rate were 88.7, 92.1, 76.0 and 94.0%, respectively. Fourteen patients developed cervical lymph node recurrence, 11 of which were distributed within the external beam radiation therapy field. We found local failures in four cases within 2 years after the treatment and in three cases after >7 years, even though the latter were difficult to distinguish from second primary cancers. CONCLUSIONS The treatment results of our institutions were equivalent to previous reports. Most cervical lymph node metastases occurred within the external beam radiation therapy field, which implied that the external beam radiation therapy dose of 20-30 Gy was insufficient to prevent late cervical lymph node metastases.


International Journal of Radiation Oncology Biology Physics | 2008

External Beam Radiotherapy for Clinically Localized Hormone-Refractory Prostate Cancer: Clinical Significance of Nadir Prostate-Specific Antigen Value Within 12 Months

Kazuhiko Ogawa; Katsumasa Nakamura; Tomonari Sasaki; Hiroshi Onishi; Masahiko Koizumi; Yoshiyuki Shioyama; Masayuki Araya; Nobutaka Mukumoto; Michihide Mitsumori; Teruki Teshima

PURPOSE To analyze retrospectively the results of external beam radiotherapy for clinically localized hormone-refractory prostate cancer and investigate the clinical significance of nadir prostate-specific antigen (PSA) value within 12 months (nPSA12) as an early estimate of clinical outcomes after radiotherapy. METHODS AND MATERIALS Eighty-four patients with localized hormone-refractory prostate cancer treated with external beam radiotherapy were retrospectively reviewed. The total radiation doses ranged from 30 to 76 Gy (median, 66 Gy), and the median follow-up period for all 84 patients was 26.9 months (range, 2.7-77.3 months). RESULTS The 3-year actuarial overall survival, progression-free survival (PFS), and local control rates in all 84 patients after radiotherapy were 67%, 61%, and 93%, respectively. Although distant metastases and/or regional lymph node metastases developed in 34 patients (40%) after radiotherapy, local progression was observed in only 5 patients (6%). Of all 84 patients, the median nPSA12 in patients with clinical failure and in patients without clinical failure was 3.1 ng/mL and 0.5 ng/mL, respectively. When dividing patients according to low (<0.5 ng/mL) and high (>or=0.5 ng/mL) nPSA12 levels, the 3-year PFS rate in patients with low nPSA12 and in those with high nPSA12 was 96% and 44%, respectively (p < 0.0001). In univariate analysis, nPSA12 and pretreatment PSA value had a significant impact on PFS, and in multivariate analysis nPSA12 alone was an independent prognostic factor for PFS after radiotherapy. CONCLUSIONS External beam radiotherapy had an excellent local control rate for clinically localized hormone-refractory prostate cancer, and nPSA12 was predictive of clinical outcomes after radiotherapy.

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