【摘要】 照射野大小和测量深度不同,将导致楔形因素发生改变,继而使楔形照射野下的剂量计算发生偏差。本文研究照射野大小及测量深度对楔形因素的影响后发现:以多数作者采用的以10cm×10cm照射野10cm深度测量的楔形因素为标准值,则方野时楔形因素最大偏差达2.9%矩形野时最大偏差达3.4%;如果以其他作者采用的以10cm×10cm照射野最大剂量深度处的楔形因素为标准值,则方野时楔形因素最大偏差达5.2%矩形野时最大偏差达5.3%。WHO的有关规定是楔形因素的精度不能超过2%1,否则必须修正。为精确治疗,我们建议应测量并使用不同楔形野的楔形因素,达到放射治疗质量保证和质量控制规定的标准。更多还原

【Abstract】 Different fields and(or)depths cause the change of wedge factors F W which result in the error of dose calcul ations for wedged-fields.This study aims at the deviations of wedge factors due to different fields and(or)depths,then finds out the max deviations of2.9%for square wedged-fields and3.4%for rectangular wedged-fields if we assume the F W for10cm×10cm field and10cm depth as standard data;and the max deviations of5.2%for square wedged -fields and5.3%for rectangular wedged-fields if we assume the F W for10cm×10cm field and d max as standard data.Thus,We suggest the measurement and usage of wedge factors according to fields and depths in use for the accurate dosimetry.更多还原