201. Simple index for validity of the evaluation point for dosimetric verification results of intensity-modulated radiation therapy using a Farmer-type ionization chamber
- Author
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Kana Washizu, Takafumi Yamano, Tetsuya Watanabe, Katsuhito Hosaka, Shogo Hatanaka, Masatsugu Hariu, Go Nakajima, Takeo Takahashi, Keiichiro Nishimura, Munefumi Shimbo, Nobuko Utsumi, and Keisuke Todoroki
- Subjects
Index (economics) ,Sensitivity and Specificity ,Imaging phantom ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Statistical significance ,Retrospective analysis ,Humans ,Radiology, Nuclear Medicine and imaging ,Point (geometry) ,Electrical and Electronic Engineering ,Radiometry ,Instrumentation ,Retrospective Studies ,Mathematics ,Radiation ,Phantoms, Imaging ,business.industry ,Radiotherapy Planning, Computer-Assisted ,Significant difference ,Reproducibility of Results ,Radiotherapy Dosage ,Intensity-modulated radiation therapy ,Condensed Matter Physics ,030220 oncology & carcinogenesis ,Ionization chamber ,Radiotherapy, Intensity-Modulated ,Nuclear medicine ,business - Abstract
PURPOSE Based on a retrospective analysis, this study aims to develop a simple index for validity of the evaluation point for the dosimetric verification of intensity-modulated radiation therapy (IMRT). METHODS The results for the dosimetric verifications of a total of 69 IMRT plans were analyzed in this study. A Farmer-type ion chamber was used as a dose detector, and a solid water-equivalent phantom was used. Index values were obtained by dividing the difference between the maximum and minimum dosages by the mean dosage of the 69 plans, and the values were classified into five groups with index value 16. A t-test was used to assess the statistical significance of the mean differences of the absolute values of the relative errors among these groups. RESULTS We found that there was no significant difference between the groups with index value
- Published
- 2018
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