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A quality assurance method for analyzing and verifying intensity modulated fields.

Lijun Ma·N Phaisangittisakul·C X Yu·M Sarfaraz
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Abstract

A quality assurance method is developed for measuring, verifying and analyzing intensity modulated radiation fields. It is applicable for rotational and fixed-beam intensity modulated radiation therapy (IMRT) treatments. A gantry-mount device was constructed to measure the transmission dose of an IMRT field using radiographic films. A double-exposure technique with optimal kernel estimate method was developed to minimize the errors from measurements. A chi2 confidence level test method was developed to detect the discrepancies between measured and prescribed IMRT fluence distributions. Our method was tested for rotational and fixed-beam IMRT treatment verifications. The method was found insensitive to the hardware-related parameters for rotational and fixed-beam IMRT deliveries. The chi2 confidence level test was found to be more sensitive than linear correlation method in detecting relative small errors for cases with a few segments or narrow regions of interest. In conclusion, we demonstrated a quantitative method for verifying and analyzing IMRT treatment deliveries.

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Models, StatisticalQuality ControlRadiometryRadiotherapy DosageRadiotherapy Planning, Computer-AssistedRadiotherapy, ConformalSensitivity and SpecificityJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, Non-P.H.S.

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Lijun Ma, N Phaisangittisakul, C X Yu, M Sarfaraz. 2003. A quality assurance method for analyzing and verifying intensity modulated fields.. https://doi.org/10.1118/1.1592896

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