Banaee Nooshin, Asgari Sepideh, Nedaie Hassan Ali
Department of Medical Radiation Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran.
Department of Medical Radiation Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran.
Appl Radiat Isot. 2018 Jul;137:154-160. doi: 10.1016/j.apradiso.2017.10.035. Epub 2018 Feb 8.
The accuracy of penumbral measurements in radiotherapy is pivotal because dose planning computers require accurate data to adequately modeling the beams, which in turn are used to calculate patient dose distributions. Gamma knife is a non-invasive intracranial technique based on principles of the Leksell stereotactic system for open deep brain surgeries, invented and developed by Professor Lars Leksell. The aim of this study is to compare the penumbra widths of Leksell Gamma Knife model C and Gamma ART 6000. Initially, the structure of both systems were simulated by using Monte Carlo MCNP6 code and after validating the accuracy of simulation, beam profiles of different collimators were plotted. MCNP6 beam profile calculations showed that the penumbra values of Leksell Gamma knife model C and Gamma ART 6000 for 18, 14, 8 and 4 mm collimators are 9.7, 7.9, 4.3, 2.6 and 8.2, 6.9, 3.6, 2.4, respectively. The results of this study showed that since Gamma ART 6000 has larger solid angle in comparison with Gamma Knife model C, it produces better beam profile penumbras than Gamma Knife model C in the direct plane.
放射治疗中半影测量的准确性至关重要，因为剂量规划计算机需要准确的数据来充分模拟射束，而这些射束又用于计算患者的剂量分布。伽玛刀是一种基于Leksell立体定向系统原理的非侵入性颅内技术，用于开放式深部脑手术，由Lars Leksell教授发明和开发。本研究的目的是比较Leksell伽玛刀C型和伽玛ART 6000的半影宽度。最初，使用蒙特卡罗MCNP6代码对两个系统的结构进行了模拟，并在验证模拟准确性后，绘制了不同准直器的射束轮廓。MCNP6射束轮廓计算表明，Leksell伽玛刀C型和伽玛ART 6000在18、14、8和4毫米准直器下的半影值分别为9.7、7.9、4.3、2.6和8.2、6.9、3.6、2.4。本研究结果表明，由于伽玛ART 6000与伽玛刀C型相比具有更大的立体角，因此在直接平面上，它产生的射束轮廓半影比伽玛刀C型更好。
