Schneider U, Pedroni E, Lomax A
Section of Physics, University of Munich, Garching, Bavaria, Germany.
Phys Med Biol. 1996 Jan;41(1):111-24. doi: 10.1088/0031-9155/41/1/009.
Computer tomographic (CT) scans are used to correct for tissue inhomogeneities in radiotherapy treatment planning. In order to guarantee a precise treatment, it is important to obtain the relationship between CT Hounsfield units and electron densities (or proton stopping powers for proton radiotherapy), which is the basic input for radiotherapy planning systems which consider tissue heterogeneities. A method is described to determine improved CT calibrations for biological tissue (a stoichiometric calibration) based on measurements using tissue equivalent materials. The precision of this stoichiometric calibration and the more usual tissue substitute calibration is determined by a comparison of calculated proton radiographic images based on these calibrations and measured radiographs of a biological sample. It has been found that the stoichiometric calibration is more precise than the tissue substitute calibration.
计算机断层扫描（CT）用于放疗治疗计划中校正组织不均匀性。为确保精确治疗，获取CT亨氏单位与电子密度（或质子放疗中的质子阻止本领）之间的关系很重要，这是考虑组织异质性的放疗计划系统的基本输入。本文描述了一种基于使用组织等效材料的测量来确定生物组织改进CT校准（化学计量校准）的方法。通过比较基于这些校准计算的质子射线照相图像与生物样品的测量射线照片，确定化学计量校准和更常用的组织替代校准的精度。已发现化学计量校准比组织替代校准更精确。
