2014 Fiscal Year Final Research Report
Changes of dose distribution during preoperative VMAT for rectal cancer
| Project/Area Number |
25861075
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Radiation science
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| Research Institution | The University of Tokyo |
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Principal Investigator |
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| Project Period (FY) |
2013-04-01 – 2015-03-31
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| Keywords | CBCT / IGRT / 直腸癌術前照射 / Rectal motion / Rectal cancer / IMRT / SIB |
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| Outline of Final Research Achievements |
There were 32 patients in this study undergoing preoperative CRT for rectal cancer. Each rectum and bladder was contoured on all planning CTs and CBCTs (day 1, 7, 13, 19, 25). The target volume was configured by adding margins (0, 3, 5, 7, 10, and 15 mm) to the rectum on planning CT. The respective percentage of rectal volume that exceeds the target volume was calculated for each of these margins. Planning CTs and series of each 5 CBCTs for 32 patients were analyzed in this study. The rectal volume tended to shrink week after week. The mean values (± SD) in the 32 series per patient of the percentage of rectum on the CBCTs exceeding target volume in which the margins of 0, 3, 5, 7, 10, and 15 mm were added to the rectum on planning CT were 20.7 ± 12.5%, 7.2 ± 8.3%, 3.9 ± 5.9%, 2.1 ± 3.9%, 0.7 ± 1.8%, and 0.1 ± 0.3%, respectively. No association was seen between the percentage of changes of bladder volume and motion of rectal centroid.
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| Free Research Field |
放射線治療
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