| Project/Area Number |
06670911
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Radiation science
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| Research Institution | Fukui Medical School |
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Principal Investigator |
YAMAMOTO Kazutaka Fukui Medical School, Dept. of Medicine Associate Professor, 医学部, 助教授 (50158268)
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| Co-Investigator(Kenkyū-buntansha) |
YAMADA Hiroki Fukui Medical School, Dept. of Medicine Assistant, 医学部附属病院, 助手 (70252004)
YOSHIDA Masanori Fukui Medical School, Dept. of Medicine Lecturer, 医学部附属病院, 講師 (00166969)
伊藤 哲 福井医科大学, 医学部, 助手 (80262616)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1995: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1994: ¥900,000 (Direct Cost: ¥900,000)
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| Keywords | Hypoxic Tissue / Radionuclide Imaging / Autoradiography / Malignant Tumor / MR Spectroscopy / Nitroimidazole Derivatives / 悪性腫瘍 |
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| Research Abstract |
Malignant tumors mostly contain hypoxic tissue, which is registant to radiation therapy. We performed the basic studies on positive imaging using a radiotracer which accumulates to hypoxic cells. 1- (N- (4'-hydroxy-pheny1) acetamide-2-nitroimidazole, a new 2-nitroimidazole derivative including a phenol residue was labeled with I-125 or I-123 by the conventional chrolamine-T method. Higher cell accumulation of radioactivity was observed in relation to decreased oxygen concentrations. Tissue distribution study in tumor bearing mice showed significant retention of radioactovity in the tumors, while, normal aerobic tissues rapidly uptook and cleared parallel to blood clearance. Autoradiography imaged irregular distribution of radioactivity in the tumor, that was similar to that of C-14 labeled 2-deoxyglucose. After radiation therapy, tumor uptake was lower than that before therapy. MR spectroscopy also showed improved Pi/b-NTP ratio and pH values after radiation therapy, that suggested reoxygenation of tumor tissue. Our preliminary studies indicate that imaging with I-123 labeled nitroimidazole derivatives may be promise for positive detection of malignant tumors and potentially in predicting tumor response to radiation therapy and/or monitoring the therapeutic effect at the earlier phase.
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