Flux G D, Webb S, Ott R J, Chittenden S J, Thomas R
Joint Department of Physics, Institute of Cancer Research, Sutton, Surrey, United Kingdom.
J Nucl Med. 1997 Jul;38(7):1059-66.
A method of dosimetry is described that quantifies the three-dimensional absorbed-dose distribution resulting from an intralesional administration of a radiolabeled monoclonal antibody, allowing for both spatial and temporal heterogeneity of distribution of the radionuclide and without the need for a calibration scan.
A mathematical model was developed to describe the distribution of activity as a function of time resulting from infusion at a single point within the solid component of a tumor. The parameters required for this model are either known directly or may be obtained from SPECT image data registered to computed tomography. Convolution of this distribution with a point-source dose kernel enabled the three-dimensional absorbed-dose distribution to be obtained.
This method was applied to a set of patient data acquired in the course of a clinical study performed at our center, and dose profiles and dose-volume histograms were produced. It was shown that the three-dimensional distribution of dose was significantly nonuniform.
Initial results suggest that this method offers a means of determining the absorbed dose distribution within a tumor resulting from intralesional infusion. This method extends the Medical Internal Radiation Dose computation, which, in these circumstances, would make erroneous assumptions. Furthermore, it will enable individual patient treatment planning and optimization of the parameters that are within the clinician's control.
描述了一种剂量测定方法，该方法可量化放射性标记单克隆抗体瘤内给药所产生的三维吸收剂量分布，考虑到放射性核素分布的空间和时间异质性，且无需校准扫描。
建立了一个数学模型，用于描述在肿瘤实体成分内单点注入后活性随时间的分布。该模型所需的参数要么可直接得知，要么可从与计算机断层扫描配准的单光子发射计算机断层扫描（SPECT）图像数据中获取。将此分布与点源剂量核进行卷积，能够获得三维吸收剂量分布。
该方法应用于在我们中心进行的一项临床研究过程中获取的一组患者数据，并生成了剂量曲线和剂量体积直方图。结果表明，剂量的三维分布明显不均匀。
初步结果表明，该方法提供了一种确定瘤内注入后肿瘤内吸收剂量分布的方法。该方法扩展了医学内照射剂量计算，在这些情况下，后者会做出错误假设。此外，它将使个体患者的治疗计划以及临床医生可控制参数的优化成为可能。
