Monte Carlo simulations and radiation dosimetry measurements of peripherally applied HDR 192Ir breast brachytherapy D-shaped applicators.
Monte Carlo simulations and radiation dosimetry measurements of peripherally applied HDR 192Ir breast brachytherapy D-shaped applicators.
复制标题
外周应用的 HDR 192Ir 乳房近距离放射治疗 D 形施源器的蒙特卡罗模拟和辐射剂量测量。
DOI：
10.1118/1.3075818
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发表时间：
2009
期刊：
影响因子：
3.8
通讯作者：
Rivard,MarkJ
中科院分区：
文献类型：
--
作者：
Yang,Yun;Rivard,MarkJ
使用 AccuBoost 注册的 D 形近距离放射治疗施用器，使用位于患者附近的平坦表面，可以获得加速部分乳房照射或放射治疗增强的适形剂量覆盖。使用蒙特卡罗方法 (MCNP5)、空气电离室 (Farmer 和 Markus) 以及聚苯乙烯和 ICRU 44 乳腺组织中的放射变色膜 (GafChromic EBT) 对三个 D 形涂药器 (D45/D53/D60) 进行剂量学表征。 HDR {sup 192}Ir 源驻留时间要么是恒定的，要么是经过优化的，以提高皮肤剂量均匀性。散射剂量随着深度的减小而减小。超出施药器孔径 10 毫米，在 0 毫米和 30 毫米深度处观察到剂量分别减少了 90% 和 51%。类似地，平面剂量均匀性随着深度的减小而改善，这也是由于散射和施放器的几何形状所致。对于所有三个施用器，在皮肤处和 30 毫米深处，施用器孔径内的剂量均匀性分别约为 11% 和 15%。使用电离室和放射变色膜对聚苯乙烯进行的深度剂量测量与蒙特卡罗结果一致，误差在 2% 以内。 30 毫米深度处的胶片剂量分布与蒙特卡罗剂量分布之间的差异在 1% 以内。
Conformal dose coverage for accelerated partial breast irradiation or radiotherapy boost can be obtained with AccuBoost registered D-shaped brachytherapy applicators using a flattened surface positioned near the patient. Three D-shaped applicators (D45/D53/D60) were dosimetrically characterized using Monte Carlo methods (MCNP5), air ionization chambers (Farmer and Markus), and radiochromic film (GafChromic EBT) in polystyrene and ICRU 44 breast tissue. HDR {sup 192}Ir source dwell times were either constant or optimized to improve skin dose uniformity. Scatter dose decreased as depth decreased. 10 mm beyond the applicator aperture, dose reductions of 90% and 51% were observed at depths of 0 and 30 mm, respectively. Similarly, planar dose uniformity improved as depth decreased and was also due to scatter and applicator geometry. Dose uniformity inside the applicator aperture was approximately 11% and 15% for all three applicators at the skin and 30 mm deep, respectively. Depth dose measurements in polystyrene using ion chamber and radiochromic film agreed with Monte Carlo results within 2%. Discrepancies between film and Monte Carlo dose profiles at 30 mm depth were within 1%.