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Featured researches published by K. Uwatsu.


Japanese Journal of Clinical Oncology | 2010

Local Control of Metastatic Lung Tumors Treated with SBRT of 48 Gy in Four Fractions: In Comparison with Primary Lung Cancer

Yasushi Hamamoto; Masaaki Kataoka; Motohiro Yamashita; Tetsu Shinkai; Yoshiro Kubo; Yoshifumi Sugawara; Takeshi Inoue; Shinya Sakai; Shoji Aono; Tadaaki Takahashi; Takatoshi Semba; K. Uwatsu

OBJECTIVE The optimal dose of stereotactic body radiotherapy (SBRT) for metastatic lung tumors has not been clarified. Local control rates of metastatic lung tumors treated with SBRT of 48 Gy in four fractions, which is one of the common dose schedules for Stage I primary lung cancer in Japan, were examined. METHODS Between 2006 and 2008, 12 metastatic lung tumors (colorectal cancer, 7; others, 5) in 10 patients and 56 lesions of Stage I primary lung cancer (T1, 43; T2, 13) in 52 patients were treated with SBRT of 48 Gy in four fractions at the isocenter. RESULTS Two-year overall survival rates were 86% for patients with metastatic lung tumors and 96% for patients with Stage I primary lung cancer (P = 0.4773). One- and 2-year local control rates were 48% and 25% for metastatic lung tumors, and 91% and 88% for Stage I primary lung cancer, respectively (P < 0.0001). CONCLUSIONS The local control rates after SBRT of 48 Gy in four fractions were significantly worse in metastatic lung tumors compared with Stage I primary lung cancer. In SBRT, metastatic lung tumors should be clearly differentiated from primary lung cancer and should be given higher doses.


Japanese Journal of Clinical Oncology | 2009

Vertebral Metastases with High Risk of Symptomatic Malignant Spinal Cord Compression

Yasushi Hamamoto; Masaaki Kataoka; Takatoshi Senba; K. Uwatsu; Yoshifumi Sugawara; Takeshi Inoue; Shinya Sakai; Shoji Aono; Tadaaki Takahashi; Shogo Oda

OBJECTIVE To find vertebral metastases with high risk of symptomatic malignant spinal cord compression (MSCC), features of vertebral metastases caused motor deficits of the lower extremities were examined. METHODS From 2004 through 2006, 78 patients with metastases of the thoracic and/or the cervical spine were treated with radiation therapy (RT). Of these, 86 irradiated lesions in 73 patients were evaluable by magnetic resonance imaging and/or computed tomography at the initiation of RT and were reviewed retrospectively in this study. Twenty-eight patients (38%) had motor deficits at the initiation of RT. Assessed factors were age, sex, primary disease (lung, breast, digestive system and other cancer), lamina involvement, main level of tumor location and vertebral-body involvement. RESULTS Incidence of motor deficits at the initiation of RT was 55% for lesions with lamina involvement and 5% for lesions without lamina involvement (P < 0.0001). Incidence of motor deficits was 15% for lesions located mainly in the cervical spine and/or the upper thoracic spine (Th1-4), 54% for lesions located mainly in the middle thoracic spine (MTS) (Th5-8) and 30% for lesions located mainly in the lower thoracic spine (Th9-12) (P = 0.0095). Age, sex, primary disease and vertebral-body involvement were not statistically significant factors for incidence of motor deficits due to MSCC (P > 0.9999, P = 0.7798, P = 0.1702 and P = 0.366, respectively). CONCLUSIONS Vertebral metastases with lamina involvement tended to cause symptomatic MSCC. Latent development of MSCC occurred more frequently in the MTS compared with other levels of the thoracic and the cervical spine.


Japanese Journal of Clinical Oncology | 2015

Kinetics differences between PSA bounce and biochemical failure in patients treated with 125I prostate brachytherapy

H. Kanzaki; Masaaki Kataoka; Atsushi Nishikawa; K. Uwatsu; Kei Nagasaki; N. Nishijima; Katsuyoshi Hashine

OBJECTIVE To determine the helpful factors to distinguish prostate-specific antigen failure from prostate-specific antigen bounce with large magnitude. METHODS From October 2004 to December 2009, 242 patients with prostate cancer treated with (125)I brachytherapy were analyzed, 88 patients were excluded because the follow-up durations were shorter than 5 years. Their median follow-up was 80.4 months (60.0-123.9). Prostate-specific antigen failure was determined using the Phoenix definition. Prostate-specific antigen bounce was defined as an increase ≥0.2 ng/ml above the nadir, followed by a spontaneous return to the nadir. Prostate-specific antigen bounce +2 was defined as a prostate-specific antigen rise by 2.0 ng/ml or more above the nadir. RESULTS The 5-year biochemical relapse-free survival rate was 90.2%. Prostate-specific antigen failure and prostate-specific antigen bounce +2 were seen in 23 patients (14.9%) and 12 patients (7.8%), respectively. On univariate analysis, age at implant (P = 0.028), T stage (P = 0.020), time to prostate-specific antigen failure or prostate-specific antigen bounce (time to onset) (P = 0.0008), prostate-specific antigen velocity (P = 0.0003) and prostate-specific antigen doubling time (P = 0.0004) were significant for the distinction between prostate-specific antigen failure and prostate-specific antigen bounce +2. On multivariate analysis, no factor was the statistically significant factor. On receiver operating characteristic curve analysis, time to onset with a cutoff value of 29.8 months, prostate-specific antigen velocity of 0.18 ng/ml/month and prostate-specific antigen doubling time of 6.3 months had the highest accuracy of 82.9, 82.9 and 82.9% for prostate-specific antigen failure, respectively. CONCLUSIONS Time to onset, prostate-specific antigen velocity and prostate-specific antigen doubling time would be helpful for distinction between prostate-specific antigen failure and prostate-specific antigen bounce +2.


Japanese Journal of Radiology | 2009

Supraclavicular failure after breast-conserving therapy in patients with four or more positive axillary lymph nodes when prophylactic supraclavicular irradiation is omitted

Yasushi Hamamoto; Masaaki Kataoka; Takatoshi Semba; K. Uwatsu; Yoshifumi Sugawara; Takeshi Inoue; Shinya Sakai; Shoji Aono; Tadaaki Takahashi; Shogo Oda

PurposeThe incidence of supraclavicular metastasis as the initial failure and the failure patterns in patients with four or more positive axillary lymph nodes (PALNs) after breast-conserving therapy (BCT) without prophylactic supraclavicular irradiation were investigated.Materials and methodsBetween 1991 and 2002, a total of 48 women with four or more PALNs underwent BCT without prophylactic supraclavicular irradiation (33 patients with 4–9 PALNs; 15 patients with ≥10 PALNs).ResultsThe median follow-up time was 50 months. Among the patients with 4–9 PALNs, 3% had isolated supraclavicular metastasis as the initial failure, and 30% had distant metastasis as the initial failure. Among patients with ≥10 PALNs, 7% had isolated supraclavicular metastasis as the initial failure, and 40% had distant metastasis as the initial failure. The 4-year isolated supraclavicular failure rates were 5% for all patients, 3% for patients with 4–9 PALNs, and 8% for patients with ≥10 PALNs.ConclusionIn patients who had undergone BCT and had had four or more PALNs, the major failure pattern was distant failure with or without locoregional failure; isolated supraclavicular failure as the initial failure comprised a less common failure pattern. Omission of prophylactic supraclavicular irradiation may be acceptable for this subset of patients.


Japanese Journal of Radiology | 2009

Incidence and patterns of isolated brain failure in stage III non-small-cell lung cancer treated with concurrent chemoradiation therapy.

Yasushi Hamamoto; Masaaki Kataoka; Takatoshi Senba; K. Uwatsu; Shogo Oda; Tadaaki Takahashi; Shoji Aono; Shinya Sakai; Takeshi Inoue; Yoshifumi Sugawara

PurposeThe incidence and patterns of isolated brain failure was examined in patients with stage III non-small-cell lung cancer (NSCLC) treated with concurrent chemoradiation (CCRT).Materials and methodsBetween 1996 and 2003, a total of 68 patients with stage III NSCLC were treated with radical CCRT. Among them, 63 patients were evaluable. Radiation therapy with a mean total dose of 61.4 Gy and chemotherapy (typically platinum-based) were administered concurrently.ResultsOther than locoregional failure, isolated brain failure was the most common failure pattern as the initial failure, occurring 2–37 months (median 6.5 months) after radical CCRT. The isolated brain failure rates as the initial failure at 1, 3, and 4 years were 9%, 13%, and 25%, respectively. Isolated brain failure as the initial failure occurred more frequently in T4 cases (39% at 4 years) compared to T1–3 cases (14% at 4 years) in our series (P = 0.0099).ConclusionExcept for locoregional failure, isolated brain failure was the most common initial failure pattern of stage III NSCLCs treated with radical CCRT. Isolated brain failure as the initial failure occurred even after 3 years. Isolated brain failure as the initial failure occurred more frequently in T4 cases than in T1-3 cases.


Journal of Radiation Research | 2018

Risk factors for pericardial effusion after chemoradiotherapy for thoracic esophageal cancer—comparison of four-field technique and traditional two opposed fields technique

Noriko Takata; Masaaki Kataoka; Yasushi Hamamoto; S. Tsuruoka; H. Kanzaki; K. Uwatsu; Kei Nagasaki; Teruhito Mochizuki

Abstract Pericardial effusion is an important late toxicity after concurrent chemoradiotherapy (CCRT) for locally advanced esophageal cancer. We investigated the clinical and dosimetric factors that were related to pericardial effusion among patients with thoracic esophageal cancer who were treated with definitive CCRT using the two opposed fields technique (TFT) or the four-field technique (FFT), as well as the effectiveness of FFT. During 2007–2015, 169 patients with middle and/or lower thoracic esophageal cancer received definitive CCRT, and 94 patients were evaluable (51 FFT cases and 43 TFT cases). Pericardial effusion was observed in 74 patients (79%) and appeared at 1–18.5 months (median: 5.25 months) after CCRT. The 1-year incidences of pericardial effusions were 73.2% and 76.7% in the FFT and TFT groups, respectively (P = 0.6395). The mean doses to the pericardium were 28.6 Gy and 31.8 Gy in the FFT and TFT groups, respectively (P = 0.0259), and the V40 Gy proportions were 33.5% and 48.2% in the FFT and TFT groups, respectively (P < 0.0001). Grade 3 pericardial effusion was not observed in patients with a pericardial V40 Gy of <40%, or in patients who were treated using the FFT. Although the mean pericardial dose and V40 Gy in the FFT group were smaller than those in the TFT group, the incidences of pericardial effusion after CCRT were similar in both groups. As symptomatic pericardial effusion was not observed in patients with a pericardial V40 Gy of <40% or in the FFT group, it appears that FFT with a V40 Gy of <40% could help minimize symptomatic pericardial effusion.


International Journal of Clinical Oncology | 2016

Impact of early tumor reduction on outcome differs by histological subtype in stage III non-small-cell lung cancer treated with definitive radiotherapy

H. Kanzaki; Masaaki Kataoka; Atsushi Nishikawa; K. Uwatsu; Kei Nagasaki; N. Nishijima; Takashi Ochi; Teruhito Mochizuki


International Journal of Radiation Oncology Biology Physics | 2017

Tumor Growth Patterns on Magnetic Resonance Imaging is Correlated With Prognosis in Patients With Locally Advanced Cervical Cancer Treated with Radiation Therapy

S. Tsuruoka; Masaaki Kataoka; K. Uwatsu; Atsushi Nishikawa; Teruhito Mochizuki


International Journal of Radiation Oncology Biology Physics | 2017

Prognostic Value of HER2 Status in Breast Cancer Patients with Brain Metastases

S. Tsuruoka; Masaaki Kataoka; K. Uwatsu; Atsushi Nishikawa; Teruhito Mochizuki


International Journal of Radiation Oncology Biology Physics | 2015

Early Tumor Regression Impacts on Outcome in Stage III Non-Small Cell Lung Cancer Treated With Definitive Radiation Therapy

H. Kanzaki; Masaaki Kataoka; N. Nishijima; K. Nagasaki; K. Uwatsu; Atsushi Nishikawa

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Takeshi Inoue

Tokyo Medical University

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