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Dive into the research topics where Tadamasa Yoshitake is active.

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Featured researches published by Tadamasa Yoshitake.


Journal of Computer Assisted Tomography | 2003

Fitz-Hugh-Curtis syndrome. Radiologic manifestation.

Akihiro Nishie; Kengo Yoshimitsu; Hiroyuki Irie; Tadamasa Yoshitake; Hitoshi Aibe; Tsuyoshi Tajima; Kenji Shinozaki; Tomohiro Nakayama; Daisuke Kakihara; Takashi Matsuura; Makoto Takahashi; Noriyuki Kamochi; Hideo Onitsuka; Hiroshi Honda

Objectives To clarify radiologic findings of Fitz-Hugh-Curtis syndrome (FHCS). Methods Thirteen women with right upper abdominal pain who were clinically diagnosed with FHCS were included. Biphasic helical computed tomography (CT) of the abdomen was performed in all patients. Posttherapeutic follow-up CT was available in 7 patients. Ultrasonography (US) was also performed in 12 patients. These imaging findings were reviewed retrospectively. Results On enhanced CT, hepatic and splenic capsular enhancement was identified in 13 and 4 patients, respectively. Hepatic capsular enhancement on the early phase, which was detected in all patients, disappeared after treatment. No adhesive band or fluid collection around the liver was evident. No enhancement of the “bare area” of the liver and spleen was seen. No definite abnormality of the liver or perihepatic region was detected by US. Conclusions Hepatic and splenic capsular enhancement on abdominal enhanced CT may be characteristic of FHCS. Enhanced CT may be a useful and noninvasive modality to help a diagnosis of FHCS, especially in young women with right upper abdominal pain without significant findings on US and gastrointestinal endoscopy.


Journal of Digital Imaging | 2006

Computer-Aided Nodule Detection on Digital Chest Radiography: Validation Test on Consecutive T1 Cases of Resectable Lung Cancer

Shuji Sakai; Hiroyasu Soeda; Naoki Takahashi; Takashi Okafuji; Tadamasa Yoshitake; Hidetake Yabuuchi; Ichiro Yoshino; Keiji Yamamoto; Hiroshi Honda; Kunio Doi

PurposeTo evaluate the usefulness of a commercially available computer-assisted diagnosis (CAD) system on operable T1 cases of lung cancer by use of digital chest radiography equipment.Materials and MethodsFifty consecutive patients underwent surgery for primary lung cancer, and 50 normal cases were selected. All cancer cases were histopathologically confirmed T1 cases. All normal individuals were selected on the basis of chest computed tomography (CT) confirmation and were matched with cancer cases in terms of age and gender distributions. All chest radiographs were obtained with one computed radiography or two flat-panel detector systems. Eight radiologists (four chest radiologists and four residents) participated in observer tests and interpreted soft copy images by using an exclusive display system without and with CAD output. When radiologists diagnosed cases as positives, the locations of lesions were recorded on hard copies. The observers’ performance was evaluated by receiver operating characteristic analysis.ResultsThe overall detectability of lung cancer cases with CAD system was 74% (37/50), and the false-positive rate was 2.28 (114/50) false positives per case for normal cases. The mean Az value increased significantly from 0.896 without CAD output to 0.923 with CAD output (P = 0.018). The main cause of the improvement in performance is attributable to changes from false negatives without CAD to true positives with CAD (19/31, 61%). Moreover, improvement in the location of the tumor was observed in 1.5 cases, on average, for radiology residents.ConclusionThis CAD system for digital chest radiographs is useful in assisting radiologists in the detection of early resectable lung cancer.


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 | 2011

Prediction of Local Failures with a Combination of Pretreatment Tumor Volume and Apparent Diffusion Coefficient in Patients Treated with Definitive Radiotherapy for Hypopharyngeal or Oropharyngeal Squamous Cell Carcinoma

Kayoko Ohnishi; Yoshiyuki Shioyama; Masamitsu Hatakenaka; Katsumasa Nakamura; Koichiro Abe; Takashi Yoshiura; Saiji Ohga; Takeshi Nonoshita; Tadamasa Yoshitake; Torahiko Nakashima; Hiroshi Honda

Diffusion-weighted magnetic resonance imaging/Apparent diffusion coefficient/Hypopharyngeal squamous cell carcinoma/Oropharyngeal squamous cell carcinoma. Purpose: Th e purpose of this study was to investigate the clinical factors for predicting local failure after definitive radiotherapy in oropharyngeal or hypopharyngeal squamous cell carcinoma. Materials and Methods: Between July 2006 and December 2008, 64 consecutive patients with squamous cell carcinoma of the hypopharynx or the oropharynx treated with definitive radiotherapy were included in this study. Clinical factors, such as pretreatment hemoglobin (Hb) level, T-stage, gross tumor volume of primary tumors (pGTV), and maximum standardized uptake value (SUVmax) on FDG-PET, were evaluated for the correlation with local failure. A subset analysis of 32 patients with MR images including diffusionweighted images (DWI) as a pretreatment evaluation was also performed. The Kaplan-Meier curves, the log-rank test, and the Cox proportional hazards model were used to evaluate these clinical factors. Results: Eleven of 64 patients experienced local recurrence, with a median follow-up time of 15 months. In the univariate analysis, Hb level (p = 0.0261), T-stage (p = 0.012), pGTV (p = 0.0025), and SUVmax (p = 0.024) were significantly associated with local failure. In the multivariate analysis, pGTV (p = 0.0070) remained an adverse factor for local control. In the subset analysis of 32 patients with DWI, the median apparent diffusion coefficient (ADC) value of primary tumors on DWI was 0.79 × 10 –3 mm 2 /s (range, 0.40–1.60 × 10 –3 mm 2 /s). Patients with a high ADC value (> 0.79 × 10 –3 mm 2 /s) had a significantly lower local control rate than patients with a low ADC value (100% vs. 44%, p = 0.0019). The rate of local failure among patients with a large pGTV and a high ADC value was 55% (6/11), whereas no local failures occurred (0%, 0/21) among patients with a small pGTV or a low ADC. Co nclusions: These results suggest that a combination of a large tumor volume and a high ADC value could be predictive of local recurrence after definitive radiotherapy in hypopharyngeal or oropharyngeal squamous cell carcinoma.


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.


Radiation Medicine | 2008

Breath-hold monitoring and visual feedback for radiotherapy using a charge-coupled device camera and a head-mounted display: system development and feasibility

Tadamasa Yoshitake; Katsumasa Nakamura; Yoshiyuki Shioyama; Satoshi Nomoto; Saiji Ohga; Takashi Toba; Takehiro Shiinoki; Shigeo Anai; Hiromi Terashima; Junji Kishimoto; Hiroshi Honda

PurposeThe aim of this study was to present the technical aspects of the breath-hold technique with respiratory monitoring and visual feedback and to evaluate the feasibility of this system in healthy volunteers.Methods and materialsTo monitor respiration, the vertical position of the fiducial marker placed on the patient’s abdomen was tracked by a machine vision system with a charge-coupled device camera. A monocular head-mounted display was used to provide the patient with visual feedback about the breathing trace. Five healthy male volunteers were enrolled in this study. They held their breath at the end-inspiration and the end-expiration phases. They performed five repetitions of the same type of 15-s breath-holds with and without a head-mounted display, respectively. A standard deviation of five mean positions of the fiducial marker during a15-s breath-hold in each breath-hold type was used as the reproducibility value of breath-hold.ResultsAll five volunteers well tolerated the breath-hold maneuver. For the inspiration breath-hold, the standard deviations with and without visual feedback were 1.74 mm and 0.84 mm, respectively (P = 0.20). For the expiration breath-hold, the standard deviations with and without visual feedback were 0.63 mm and 0.96 mm, respectively (P = 0.025).ConclusionOur newly developed system might help the patient achieve improved breath-hold reproducibility.


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.


Physics in Medicine and Biology | 2009

A clinical evaluation of visual feedback-guided breath-hold reproducibility of tumor location

Tadamasa Yoshitake; Yoshiyuki Shioyama; Katsumasa Nakamura; Saiji Ohga; Takeshi Nonoshita; Kayoko Ohnishi; Kotaro Terashima; Hidetaka Arimura; Hideki Hirata; Hiroshi Honda

The purpose of this study was to evaluate the reproducibility of visual feedback-guided breath-hold using a machine vision system with a charge-coupled device camera and a monocular head-mounted display. Sixteen patients with lung tumors who were treated with stereotactic radiotherapy were enrolled. A machine vision system with a charge-coupled device camera was used for monitoring respiration. A monocular head-mounted display was used to provide the patient with visual feedback about the breathing trace. The patients could control their breathing so that the breathing waveform would fall between the upper and lower threshold lines. Planning and treatment were performed under visual feedback-guided expiratory breath-hold. Electronic portal images were obtained during treatment. The range of cranial-caudal motion of the tumor location during each single breath-hold was calculated as the intra-breath-hold (intra-BH) variability. The maximum displacement between the two to five averaged tumor locations of each single breath-hold was calculated as the inter-breath-hold (inter-BH) variability. All 16 patients tolerated the visual feedback-guided breath-hold maneuvers well. The intra- and inter-BH variability of all patients was 1.5 +/- 0.6 mm and 1.2 +/- 0.5 mm, respectively. A visual feedback-guided breath-hold technique using the machine vision system is feasible with good breath-hold reproducibility.


Radiation Medicine | 2007

Erythema multiforme and Stevens-Johnson syndrome following radiotherapy

Tadamasa Yoshitake; Katsumasa Nakamura; Yoshiyuki Shioyama; Tomonari Sasaki; Saiji Ooga; Madoka Abe; Yusuke Urashima; Kazunori Urabe; Hiromi Terashima; Hiroshi Honda

Erythema multiforme (EM) and Stevens-Johnson syndrome (SJS) are thought to be hypersensitivity syndromes with various causes, and radiotherapy might be one of the causes of these syndromes. We herein report two cases of EM/SJS following radiotherapy. The first case was a 63-year-old woman with breast cancer. At the end of postoperative radiotherapy with 60 Gy, severe pruritic erythema appeared in the irradiated area and spread over the whole body. She was diagnosed with EM by a skin biopsy. The second case was a 77-year-old woman with uterine cervical cancer who underwent postoperative radiotherapy. At a dose of 30.6 Gy, pruritic redness appeared in the irradiated area and the precordial region, and it became widespread rapidly with polymorphic transformation. Although without any histological confirmation, SJS was strongly suspected because of her pruritic conjunctivitis. Because both patients were given medicines during irradiation, radiotherapy may not be the only cause of EM/SJS. However, it should be noted that radiotherapy might trigger EM/SJS.

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