Bhola Subhalaxmi, Selvam T Palani, Sridhar Sahoo, Vishwakarma Ramkrishna S
Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Anushaktinagar, Mumbai, India.
J Med Phys. 2012 Jul;37(3):129-37. doi: 10.4103/0971-6203.99228.
We present a simple analytic tool for calculating the dose rate distribution in water for a new BEBIG high-dose-rate (HDR) (60)Co brachytherapy source. In the analytic tool, we consider the active source as a point located at the geometric center of the (60)Co material. The influence of the activity distribution in the active volume of the source is taken into account separately by use of the line source-based geometric function. The exponential attenuation of primary (60)Co photons by the source materials ((60)Co and stainless-steel) is included in the model. The model utilizes the point-source-based function, f(r) that represents the combined effect of the exponential attenuation and scattered photons in water. We derived this function by using the published radial dose function for a point (60)Co source in an unbounded water medium of radius 50 cm. The attenuation coefficients for (60)Co and the stainless-steel encapsulation materials are deduced as best-fit parameters that minimize the different.
我们提出了一种简单的分析工具，用于计算新型BEBIG高剂量率（HDR）（60）钴近距离放射治疗源在水中的剂量率分布。在该分析工具中，我们将有源源视为位于（60）钴材料几何中心的一个点。通过使用基于线源的几何函数，分别考虑了源活性体积内活度分布的影响。模型中包含了源材料（（60）钴和不锈钢）对初级（60）钴光子的指数衰减。该模型利用基于点源的函数f(r)，它表示水中指数衰减和散射光子的综合效应。我们通过使用已发表的关于半径为50 cm的无界水介质中（60）钴点源的径向剂量函数推导出了这个函数。将（60）钴和不锈钢封装材料的衰减系数推导为使差异最小化的最佳拟合参数。
