Takeji Sakae

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Secondary neutron ambient dose equivalents per the treatment absorbed dose in passive carbon-ion and proton radiotherapies were measured using a rem meter, WENDI-II at two carbon-ion radiotherapy facilities and four proton radiotherapy facilities in Japan. Our measured results showed that (1) neutron ambient dose equivalent in carbon-ion radiotherapy is(More)
PURPOSE Our previous results for treatment of hepatocellular carcinoma with proton beam therapy (PBT) revealed excellent local control. In this study, we focused on the impact of PBT on normal liver function. METHODS AND MATERIALS The subjects were 259 patients treated with PBT at the University of Tsukuba between January 2001 and December 2007. We(More)
Particle radiotherapy using proton and heavy ion beams has shown improved clinical results and is a promising cancer therapy which is expected to gradually spread in Japan. There are, however, no special regulations for radiotherapy treatment facilities. They have been operated under the same safety regulations as for a research facility using a research(More)
PURPOSE The purpose of this study is to investigate the correlation between the respiratory waveform measured using a respiratory sensor and three-dimensional (3D) tumor motion. METHODS AND MATERIALS A laser displacement sensor (LDS: KEYENCE LB-300) that measures distance using infrared light was used as the respiratory sensor. This was placed such that(More)
The purpose of this study was to determine the difference, if any, in the thermal stability of collagen in mineralized and demineralized dentine compared to that in unmineralized tissues, using differential scanning calorimetry, DSC. Human tooth dentin blocks, about 1 x 1 x 2 mm in size, were used in this study. Some dentin blocks were demineralized using a(More)
A micro-focus X-ray diffractometer was applied to a ground section of sialolith, and localization of brushite and whitlockite was found. The sialolith was composed of a central core of organic material and a layered cortex of mineral components. The major component of the mineral cortex is apatite. Brushite and whitlockite locate independently at the(More)
An unusual case of cleidocranial dysplasia associated with more than 60 unerupted teeth is presented and examined with light and scanning electron microscopes and crystallographic techniques. The present case revealed pseudoprognathism with facial asymmetry, the right side being larger than the left. The extracted teeth showed enamel hypoplasia in light and(More)
In current radiotherapy, neutrons are produced in a photonuclear reaction when incident photon energy is higher than the threshold. In the present study, a method of discriminating the neutron component was investigated using an imaging plate (IP) in the neutron-gamma-ray mixed field. Two types of IP were used: a conventional IP for beta- and gamma rays,(More)
PURPOSE To clarify the properties of clinical high-energy protons by comparing with clinical high-energy X-rays. MATERIALS AND METHODS Human tumor cell lines, ONS76 and MOLT4, were irradiated with 200 MeV protons or 10 MV X-rays. In situ DNA double-strand breaks (DDSB) induction was evaluated by immunocytochemical staining of phosphorylated histone H2AX(More)