1993 Fiscal Year Final Research Report Summary
Basic and Clinical Study of Radiation Therapy for Malignant Gliomas
| Project/Area Number |
03454343
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Cerebral neurosurgery
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| Research Institution | University of Tokyo |
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Principal Investigator |
MATSUTANI Masao University of Tokyo, Department of Neurosurgery, Associate Professor, 医学部(病), 助教授 (90010454)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAKURA Kintomo Tokyo Women's Medical School, Department of Neurosurgery, Professor, 教授 (90109984)
NAGASHIMA Tadashi University of Tokyo, Department of Neurosurgery, Assistant Professor, 医学部(病), 助手 (70217991)
MOMOSE Toshimitsu University of Tokyo, Department of Radiology, Assistant Professor, 医学部(病), 助手 (20219992)
KAWAMOTO Shunsuke University of Tokyo, Department of Neurosurgery, Assistant Professor, 医学部(病), 助手 (00231275)
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| Project Period (FY) |
1991 – 1993
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| Keywords | Malignant Glioma / Radiation Therapy / Intraoperative Radiation Therapy |
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| Research Abstract |
In the analysis of 71 operated patients treated by conventional external radiation therapy (mean dose 60.6Gy) combined with radiosensitizing agents, the combination of ACNU and vincristine with or without nicardipine resulted in the significantly longer survival, resulting in the median survival of 101weeks.
Among various radiation modalities to deliver a high dose to the tumor area, we chose a large, single irradiation dose during the operation (intraoperative radiation therapy, IORT). Treatment results of 30 patients with glioblastoma treated by IORT (mean 18.3Gy) combined with external radiation therapy (mean 58.5Gy) resulted in a median survival of 119 weeks and a 2-year survival rate of 61% ; most recurrent tumors, however, were observed around the primary site.
The most characteristic findings obtained in irradiated glioblastoma tissue were extensive ischemic coagulation necrosis and coexisting radioresistant grade I and II viable tumor areas. The labeling index of bromodeoxyuridine (BUdR), which is taken up by cells in S-phase, was analyzed after radiation therapy. The mean LI fell to 3.8% from the initial 8.2%, and the lowest LI,less than 0.1%, was obtained in cases treated with a 70Gy dose.
These results apparently indicate that areas adjacent to the margin of almost complete removal should be irradiated with a sufficient dose to sterilize the remaining malignant remnants and that infiltrating areas around the tumor bulk should be treated by the conventional radiation therapy with a dose of 70Gy or more.
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