| Project/Area Number |
62570479
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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 | Kansai Medical University |
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Principal Investigator |
TANAKA Yoshimasa Department of Radiology, Kansai Medical University, 医学部, 教授 (40131445)
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| Co-Investigator(Kenkyū-buntansha) |
HARIMA Keizo Department of Radiology, Kansai Medical University, 医学部, 助手 (20121973)
SAWADA Satoshi Department of Radiology, Kansai Medical University, 医学部, 講師 (80121937)
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| Project Period (FY) |
1987 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1988: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1987: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | Perfluorochemicals(PFC) / Angiotension II / 放射線増感効果 / Perfluorochemicals(PFC) / AngiotensinII / パーフルオロケミカル / 局所酸素分圧 / 低酸素細胞 / 放射線増感剤 / 放射線増感率 |
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| Research Abstract |
It is believed that the presence of radiobiologically hypoxic cells in human tumors is the major limiting factors for the complete control of tumors by radiotherapy. Perfluorochemicals (PFC) are able to absorb a great amount of oxygen in a high pO_2 environment and rapidly releases oxygen when the environmental pO_2 is low.In the present study, the changes in transplanted tumor pO_2 and the radiosensitizing effects by treatment with PFC and Carbogen(95%O_2 + 5% CO_2) or combination od AGII were investigated. The TCD_<50> (50% Tumor Cure Dose) was modified by factors of 1.47 + 0.03(S.E.) by treating the animals with carbogen plus PFC. The dose modification factor (DMF) for the skin reaction was 1.15 + 0.12(S.E.) and then, Therapeutic Gain Factor (TGF) was 1.28 + 0.04.
The data presented in this report clearly demonstrate that an i.v. injection of PFC with Carbogen breathing can significantly increase the response of tumors to X-rays as measured by tumor growth and tumor cure. The therapeutic gain obtained in this study for a single exposure was 1.28, whereas larger therapeutic gains than we obtained in the present study was also reported by other investigators.
Angiotension II(AG II) also increased pO_2 in the central area especially. This may indicate that AG II is useful in a larger tumor having a lot of hypovascular portion. The Phase I and II of clinical trials of PFC for radiotherapy patients is in progress in several medical centers in USA and Japan.
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