JaLCDOI 10.18926/AMO/31638
FullText URL fulltext.pdf
Author Kuroda, Masahiro| Inamura, Keiji| Tahara, Seiji| Kurabayashi, Yuzuru| Akagi, Tadaatsu| Asaumi, Junichi| Togami, Izumi| Takemoto, Mitsuhiro| Honda, Osamu| Morioka, Yasuki| Kawasaki, Shoji| Hiraki, Yoshio|
Abstract <p>We developed a reliable system for the irradiation of xenografted tumors in mice which allows for accurate local irradiation under specific pathogen-free conditions. The system presented here consists of acrylic supports for mice and an acrylic box connected to a pump through 0.22 microns pore-sized filters. Mice with xenotransplanted tumors growing on their right hind legs were set on the supports and put into the box in a laminar flow hood. The tumors of 7 mice were irradiated simultaneously with X-rays of 6 and 10 MV generated by a linear accelerator at a dose rate of 3.1-4.7 Gy/min. The air was ventilated through filters during irradiation in the closed box. Microorganism tests confirmed that no bacteria entered or left the box. One of the significant characteristics of this setup is that it allows for irradiation under conditions of acute hypoxia, which is obtained using an integrated tourniquet. The dose variation among 7 tumors was less than 1%. The rest of the mouse's body was shielded effectively by a half-field technique and a lead block. As a result, the whole body dose for the mice was 0-4% of the total dose absorbed by the tumor. Due to the high dose rate and the ability to irradiate 7 mice simultaneously under specific pathogen-free conditions, this new system can be considered a time-saving and valuable tool for radiation oncology research.</p>
Keywords animal experiment mouse radiotherapy linear accelerator specirfic pathogen-free
Amo Type Article
Published Date 1999-06
Publication Title Acta Medica Okayama
Volume volume53
Issue issue3
Publisher Okayama University Medical School
Start Page 111
End Page 118
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
Web of Sience KeyUT 000081201100002
JaLCDOI 10.18926/AMO/32638
FullText URL fulltext.pdf
Author Kuroda, Masahiro| Inamura, Keiji| Tahara, Seiji| Mimura, Seiichi| Mikami, Yasutaka| Kawasaki, Shoji| Hiraki, Yoshio|
Abstract <p>Simultaneous radiohyperthermotherapy (SRH) is a combined hyperthermia-radiation therapy in which irradiation is given during heating. Mutual interference between the high energy radiotherapy system (Toshiba LMR-15A) and the 13.56 MHz capacitive heating system (Omron HEH-500C) was tested with phantom materials prior to a clinical trial with SRH. The energy and flatness of irradiation were not affected by the heating system within the range of clinical use. The high energy radiotherapy system did not affect the increase or distribution of temperature during simultaneous treatment. The results of this phantom study indicated that these apparatuses would not produce clinically significant mutual interference during SRH. A clinical trial was performed on a 57-year-old woman with postoperative recurrence of rectal cancer. This is the first reported clinical case treated with true SRH in which external irradiation was administered during mid capacitive heating. Twelve SRH treatments were performed on the recurrent lesion at a frequency of twice a week for six weeks using the apparatuses described above. There was a significant reduction in pain after treatment. The tumor marker carcinoembryonic antigen (CEA) level decreased after treatment. On CT images taken after treatment, the tumor site became a low density area which indicated necrosis. There were no side effects. These results suggest that further clinical study of SRH should be performed to clarify its advantages.</p>
Keywords hyperthermia capacitive heating radiotherapy phantom study simultaneous radio-hyperthermotherapy
Amo Type Article
Published Date 1992-12
Publication Title Acta Medica Okayama
Volume volume46
Issue issue6
Publisher Okayama University Medical School
Start Page 417
End Page 426
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 1485536
Web of Sience KeyUT A1992KE49600003
JaLCDOI 10.18926/AMO/56072
FullText URL 72_3_267.pdf
Author Matsuura, Ryutaro| Goto, Sachiko| Sato, Shuhei| Akagi, Noriaki| Tahara, Seiji|
Abstract We validated a navigator-echo-triggered sequence that drives magnetization before cardiac-gated inversion recovery T1 turbo field echo acquisition, in the sedated free-breathing pediatric population. Cardiac magnetic resonance imaging was performed on sedated infants with single ventricle. We calculated the signal-to-noise ratios and contrast-to-noise ratios of 2 groups of images obtained using respiratory triggering with and without navigator echo. All images were then visually assessed by 2 observers. The signal-to-noise ratio and the contrast-to-noise ratio were significantly higher with than without navigator echo (p<0.01; p<0.05). The visual assessment scores were also consistently better with than without navigator echo (p<0.01). Free-breathing navigator echo was found to have the advantage of decreasing the motion artifact caused by respiration. Cardiacgated inversion recovery T1 turbo field echo sequence for free-breathing navigator-echo-triggered respiration allows for the acquisition, in sedated infants, of diagnostic images whose quality exceeds that of the non-navigator-echo-triggered alternative.
Keywords magnetic resonance imaging navigator echo inversion recovery T1 turbo field echo cardiac infant
Amo Type Original Article
Published Date 2018-06
Publication Title Acta Medica Okayama
Volume volume72
Issue issue3
Publisher Okayama University Medical School
Start Page 267
End Page 273
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
Copyright Holders CopyrightⒸ 2018 by Okayama University Medical School
File Version publisher
Refereed True
PubMed ID 29926004