Pacyna L G, Darby M, Prado K
Duke University Medical Center, Durham, NC 27710, USA.
Med Dosim. 1997 Winter;22(4):319-24. doi: 10.1016/s0958-3947(97)00107-6.
For Total Body Irradiation (TBI) the midline dose along the long axis of the body should vary by no more than +/- 10% compared to the dose received at the prescription point. Compensating filters are often made to compensate for contour irregularities. This paper describes an experimental method using Thermoluminescent Dosimetry (TLD) to verify the appropriateness of dose compensation provided by compensating filters. An AP/PA treatment geometry was used with an 18 MV photon beam. TLDs were placed in the midplane and on the surface of an anthropomorphic phantom in five different areas. Three different lead compensating filters were designed to provide proper compensation, overcompensation, and undercompensation. The TLD readings were compared with calculated doses and the measurements correlated favorably. The measurements were sensitive enough to detect dose variations due to improper compensation. These results demonstrate that TLD is a reliable method of verifying dose compensation provided by compensating filters in TBI.
对于全身照射（TBI），沿身体长轴的中线剂量与处方点所接受的剂量相比，变化应不超过±10%。通常制作补偿滤过器来补偿轮廓不规则性。本文描述了一种使用热释光剂量测定法（TLD）来验证补偿滤过器所提供剂量补偿是否合适的实验方法。采用前后/后前治疗野设置，使用18MV光子束。TLD放置在体模中平面以及拟人化体模表面的五个不同区域。设计了三种不同的铅补偿滤过器，分别提供适当补偿、过度补偿和补偿不足。将TLD读数与计算剂量进行比较，测量结果具有良好的相关性。这些测量足够灵敏，能够检测到由于补偿不当导致的剂量变化。这些结果表明，TLD是验证TBI中补偿滤过器所提供剂量补偿的可靠方法。
