Soares C G, Halpern D G, Wang C K
National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
Med Phys. 1998 Mar;25(3):339-46. doi: 10.1118/1.598204.
The calibration of a catheter-based system to be used for therapeutic radiation treatment to prevent restenosis following interventional coronary procedures is described. The primary dosimetry was performed ionometrically using an extrapolation chamber equipped with a 1-mm diameter collecting electrode to measure absorbed dose in tissue equivalent plastic at a depth of 2 mm. These results are compared with measurements with radiochromic dye film, which is also used to characterize sources for axial and trans-axial uniformity, and to determine dose distributions at various depths. A protocol for dose calculation based on that of AAPM TG43 is suggested for these sources, and examples of its use are given for the calculation of the enhancement effect on dose rate from a single seed source due to neighboring seeds. Monte Carlo calculations were also performed to validate the measured results.
描述了一种用于治疗性放射治疗的基于导管的系统的校准，以防止介入性冠状动脉手术后的再狭窄。主要剂量测定采用配备1毫米直径收集电极的外推电离室进行离子测量，以测量组织等效塑料中2毫米深度处的吸收剂量。将这些结果与用放射变色染料薄膜进行的测量结果进行比较，放射变色染料薄膜也用于表征轴向和跨轴均匀性的源，并确定不同深度处的剂量分布。针对这些源，建议了一种基于AAPM TG43的剂量计算方案，并给出了其用于计算相邻种子对单个种子源剂量率增强效应的示例。还进行了蒙特卡罗计算以验证测量结果。
