Kaori Asai
Kyushu University
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Featured researches published by Kaori Asai.
Journal of Radiation Research | 2013
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.
Journal of Radiation Research | 2013
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.
International Journal of Radiation Oncology Biology Physics | 2012
Kazushige Atsumi; Yoshiyuki Shioyama; Hidetaka Arimura; Kotaro Terashima; Takaomi Matsuki; Saiji Ohga; Tadamasa Yoshitake; Takeshi Nonoshita; Daisuke Tsurumaru; Kayoko Ohnishi; Kaori Asai; Keiji Matsumoto; Katsumasa Nakamura; Hiroshi Honda
PURPOSE To determine clinical factors for predicting the frequency and severity of esophageal stenosis associated with tumor regression in radiotherapy for esophageal cancer. METHODS AND MATERIALS The study group consisted of 109 patients with esophageal cancer of T1-4 and Stage I-III who were treated with definitive radiotherapy and achieved a complete response of their primary lesion at Kyushu University Hospital between January 1998 and December 2007. Esophageal stenosis was evaluated using esophagographic images within 3 months after completion of radiotherapy. We investigated the correlation between esophageal stenosis after radiotherapy and each of the clinical factors with regard to tumors and therapy. For validation of the correlative factors for esophageal stenosis, an artificial neural network was used to predict the esophageal stenotic ratio. RESULTS Esophageal stenosis tended to be more severe and more frequent in T3-4 cases than in T1-2 cases. Esophageal stenosis in cases with full circumference involvement tended to be more severe and more frequent than that in cases without full circumference involvement. Increases in wall thickness tended to be associated with increases in esophageal stenosis severity and frequency. In the multivariate analysis, T stage, extent of involved circumference, and wall thickness of the tumor region were significantly correlated to esophageal stenosis (p = 0.031, p < 0.0001, and p = 0.0011, respectively). The esophageal stenotic ratio predicted by the artificial neural network, which learned these three factors, was significantly correlated to the actual observed stenotic ratio, with a correlation coefficient of 0.864 (p < 0.001). CONCLUSION Our study suggested that T stage, extent of involved circumference, and esophageal wall thickness of the tumor region were useful to predict the frequency and severity of esophageal stenosis associated with tumor regression in radiotherapy for esophageal cancer.
Technology in Cancer Research & Treatment | 2013
K. Terashima; Katsumasa Nakamura; Yoshiyuki Shioyama; Tomonari Sasaki; Saiji Ohga; Takeshi Nonoshita; Tadamasa Yoshitake; Kazushige Atsumi; Kaori Asai; Masakazu Hirakawa; S. Anai; Hiroshi Yoshikawa; Hiroshi Honda
The purpose of this study is to evaluate the real-time respiratory motion of the prostate and surrounding tissues/organs in the supine and prone positions and to investigate, using cine-MRI, whether a belly board can reduce respiratory-induced motion in the prone position. Cine-MRI scans were made of 13 volunteers in the supine and prone positions on a flat board and in two different prone positions using a belly board. Images in cine mode were recorded for 20 seconds. For each session, the points of interest (POIs) were located at the apex, base, mid-anterior surface and mid-posterior surface of the prostate; the tip of the seminal vesicle; the pubic symphysis; and the sacrum. The maximum range and standard deviation (SD) of the displacement from the mean value were calculated. The SDs for each of the four different positions were compared using a paired t-test. Respiratory-induced prostate motion was significantly larger in the prone position than in the supine position. However, when a belly board was used in the prone position, motion in the prostate and surrounding tissues/organs was significantly reduced. There were no significant differences between the two different positions using a belly board in any of the POIs.
International Journal of Clinical Oncology | 2014
Katsumasa Nakamura; Tomonari Sasaki; Saiji Ohga; Tadamasa Yoshitake; Kotaro Terashima; Kaori Asai; Keiji Matsumoto; Yoshiyuki Shioyama; Hiroshi Honda
Radiotherapy plays an important role in the treatment of various malignancies, and intensity-modulated radiotherapy (IMRT) is an attractive option because it can deliver precise conformal radiation doses to the target while minimizing the dose to adjacent normal tissues. IMRT provides a highly conformal dose distribution by modulating the intensity of the radiation beam. A number of malignancies have been targeted by IMRT; this work reviews published data on the major disease sites treated with IMRT. The dosimetric advantage of IMRT has resulted in the significant reduction of adverse effects in some tumors. However, there are few clinical trials comparing IMRT and three-dimensional conformal radiotherapy (3D-CRT), and no definite increase in survival or the loco-regional control rate by IMRT has been demonstrated in many malignancies. IMRT also requires greater time and resources to complete compared to 3D-CRT. In addition, the cost–effectiveness of IMRT versus 3D-CRT has not yet been established.
Journal of Radiation Research | 2014
Saiji Ohga; Katsumasa Nakamura; Yoshiyuki Shioyama; Katsunori Tatsugami; Tomonari Sasaki; Takeshi Nonoshita; Tadamasa Yoshitake; Kaori Asai; Hideki Hirata; Seiji Naito; Hiroshi Honda
We evaluated the predictive factors of acute urinary morbidity (AUM) after prostate brachytherapy. From November 2005 to January 2007, 62 patients with localized prostate cancer were treated using brachytherapy. The 125Iodine (125I) seed-delivering method was a modified peripheral pattern. The prescribed dose was 144 Gy. Urinary morbidity was scored at 3 months after implantation. The clinical and treatment parameters were analysed for correlation with AUM. In particular, in this study, Du90 (the minimal dose received by 90% of the urethra), Dup90 (the minimal dose received by 90% of the proximal half of the urethra on the bladder side) and Dud90 (the minimal dose received by 90% of the distal half of the urethra on the penile side) were analysed. We found that 43 patients (69.4%) experienced acute urinary symptoms at 3 months after implantation. Of them, 40 patients had Grade 1 AUM, one patient had Grade 2 pain, and two patients had Grade 2 urinary frequency. None of the patients had ≥Grade 3. Univariate and multivariate analysis revealed that Du90 and Dup90 were significantly correlated with AUM. In this study, Du90 and Dup90 were the most significant predictors of AUM after prostate brachytherapy.
Seminars in Ophthalmology | 2017
Sawako Hashimoto; Hiroshi Yoshikawa; Michiko Miyagi; Yoko Onishi; Saiji Ohga; Kaori Asai; Tatsuro Ishibashi
ABSTRACT Purpose: To investigate the interval between low-dose radiotherapy and radiation-induced cataracts, and the factors affecting this interval, in patients with lymphoproliferative disease of the ocular adnexa. Methods: A retrospective case series of 73 eyes of 59 patients who underwent radiotherapy from 1996 to 2005 with total doses ranging from 24 to 30 Gy was conducted. We investigated the relationships between the radiation-associated cataract formation intervals and age, gender, diabetes, and the use of corticosteroids. Results: The mean interval was 36 months. None of the patients with lens shield developed cataracts. Age was inversely and significantly and gender was not significantly associated with the interval from first radiotherapy to cataract occurrence. The intervals did not differ significantly according to the presence of diabetes and corticosteroid therapy. Conclusions: The mean interval from the start of radiation therapy to radiation-related cataract formation was 36 months and age was a significant factor affecting this interval.
Molecular and Clinical Oncology | 2017
Tomoyasu Yoshihiro; Kenji Tsuchihashi; Hitoshi Kusaba; Torahiko Nakashima; Teppei Obara; Kenta Nio; Kotoe Takayoshi; Hiroyuki Kodama; Nobuhiro Tsuruta; Hideyuki Kiyohara; Kaori Asai; Eiji Harada; Kenjiro Kamezaki; Takeshi Arita; Masanobu Sato; Hidetaka Yamamoto; Shuji Arita; Hiroshi Ariyama; Keita Odashiro; Yoshinao Oda; Koichi Akashi; Eishi Baba
Distant metastasis of primary squamous cell carcinoma (SCC) of the thyroid gland is rare and, to the best of our knowledge, cardiac metastasis has not been reported to date. A 57-year-old man underwent surgery and adjuvant chemoradiotherapy for stage IVA SCC of the thyroid gland. After 3 months, the patient was admitted to the Kyushu University Hospital (Fukuoka, Japan) with subcutaneous hematomas of the left thigh and lower leg, and he was diagnosed with cardiac and mediastinal lymph node metastases of SCC of the thyroid gland with severe disseminated intravascular coagulation (DIC). Echocardiography revealed a mass, 52 mm in greatest diameter, protruding from the interventricular septum towards the right ventricle. Weekly administration of paclitaxel and concurrent irradiation of the cardiac and lymph node metastases were performed. Eighteen days after the initiation of chemoradiotherapy, the DIC and hematomas had significantly improved, and the cardiac metastasis was stable. However, 2 months after admission, the patient developed dyspnea and multiple nodular shadows appeared to be spreading in the subpleura of the lungs bilaterally, which were initially suspected to be pulmonary tumor embolisms. Prednisolone and subsequent administration of lenvatinib were not effective and the patient succumbed to respiratory failure. Severe DIC caused by extremely rare cardiac metastasis of SCC of the thyroid gland was effectively controlled by chemoradiotherapy. However, intensive local control appears to be required for this condition.
International Journal of Clinical Oncology | 2017
Torahiko Nakashima; Ryuji Yasumatsu; Kaori Asai; Hideoki Uryu; Ryunosuke Kogo; Takashi Nakagawa
BackgroundThe role of induction chemotherapy (IC) in the treatment of resectable advanced head and neck squamous cell carcinoma has not been elucidated, and the most effective IC regimen for chemoselection is still unknown. At our institute we have not used the triple combination of docetaxel, cisplatin, fluorouracil (TPF) for chemoselection, but rather the double combination of docetaxel + cisplatin (TP). The aim of this study is to report the outcome of patients with advanced hypopharyngeal cancer treated by single cycle of IC with TP followed by chemoradiation (CRT) or surgery.MethodsA total of 29 patients with resectable advanced hypopharyngeal cancer who were treated with a single cycle of IC were entered into the study. Responders were treated by CRT while nonresponders underwent surgery. Outcomes were analyzed using the Kaplan–Meier method.ResultsA single cycle of IC with TP achieved response in 21 of the 29 patients. The major side effect was neutropenia which could be managed without delaying the sequential treatment. The 2-year overall survival and disease-specific survival were both 74.0% (stage III 100%, stage IVA 69.1%). The cumulative 2-year laryngeal preservation rate was 100% for stage III and 53.6% for stage IVA.ConclusionA single cycle of IC with the combination of docetaxel + cisplatin may be sufficient to select advanced hypopharyngeal cancer patients with radio-sensitivity. IC intended for organ preservation strategies should be low toxic. Our strategy may be a useful for providing the benefits of IC and the opportunity for curative surgery without delay.
International Journal of Radiation Oncology Biology Physics | 2010
Kaori Asai; Yoshiyuki Shioyama; Katsumasa Nakamura; Tomonari Sasaki; Saiji Ohga; Takeshi Nonoshita; Tadamasa Yoshitake; Kayoko Ohnishi; Kotaro Terashima; Keiji Matsumoto; Hideki Hirata; Hiroshi Honda