Department of Radiation Oncology, Calvary Mater Newcastle, Waratah, New South Wales, Australia.
Med Phys. 2011 Oct;38(10):5330-7. doi: 10.1118/1.3626573.
An anthropomorphic pelvic phantom was designed and constructed to meet specific criteria for multicenter radiotherapy dosimetric intercomparison.
Three dimensional external and organ outlines were generated from a computed tomography image set of a male pelvis, forming the basis of design for an anatomically realistic phantom. Clinically relevant points of interest were selected throughout the dataset where point-dose values could be measured with thermoluminescence dosimeters and a small-volume ionization chamber. Following testing, three materials were selected and the phantom was manufactured using modern prototyping techniques into five separate coronal slices. Time lines and resource requirements for the phantom design and manufacture were recorded. The ability of the phantom to mimic the entire treatment chain was tested.
The phantom CT images indicated that organ densities and geometries were comparable to those of the original patient. The phantom proved simple to load for dosimetry and rapid to assemble. Due to heat release during manufacture, small air gaps and density heterogeneities were present throughout the phantom. The overall cost for production of the prototype phantom was comparable to other commercial anthropomorphic phantoms. The phantom was shown to be suitable for use as a "patient" to mimic the entire treatment chain for typical external beam radiotherapy for prostate and rectal cancer.
The phantom constructed for the present study incorporates all characteristics necessary for accurate Level III intercomparison studies. Following use in an extensive Level III dosimetric comparison over a large time scale and geographic area, the phantom retained mechanical stability and did not show signs of radiation-induced degradation.
设计并构建了一个拟人化骨盆体模，以满足多中心放疗剂量学比对的特定标准。
从男性骨盆的计算机断层扫描图像集中生成三维外部和器官轮廓，为具有解剖学真实性的体模设计提供基础。在整个数据集内选择了与临床相关的感兴趣点，可在这些点使用热释光剂量计和小体积电离室测量点剂量值。经过测试，选择了三种材料，并使用现代原型制作技术将体模制造为五个单独的冠状切片。记录了体模设计和制造的时间线和资源需求。测试了体模模拟整个治疗链的能力。
体模的 CT 图像表明，器官密度和几何形状与原始患者相似。体模在进行剂量测定时易于加载，组装速度快。由于制造过程中释放热量，整个体模中存在小的空气间隙和密度不均匀性。原型体模的总制造成本与其他商用拟人体模相当。体模适合用作“患者”，模拟前列腺癌和直肠癌的典型外照射治疗的整个治疗链。
本研究构建的体模包含了进行准确的三级相互比较研究所需的所有特征。在经过广泛的三级剂量学比较，并在较大的时间和地理范围内使用后，体模保持了机械稳定性，没有显示出辐射诱导降解的迹象。
