Fallows Peter, Wright Gavin, Bownes Peter
Leeds Cancer Centre, Leeds Teaching Hospitals, Leeds, United Kingdom.
J Radiosurg SBRT. 2019;6(3):227-233.
The aim of this investigation was to develop a standardised method for using the inverse planning module in Leksell GammaPlan.
Leksell GammaPlan version 10 and higher contains an inverse planning module, consisting of functions to automatically fill a target volume with shots and subsequently optimise their resulting dosimetry. A standardised method for using the inverse planning module was developed for metastases, using the following optimisation parameter weightings: {coverage 0.9, selectivity 0.1, gradient index (GI) 0.2, }. 25 plans produced using these parameters were compared to manually produced clinical plans. Additionally, the 25 plans were manually adjusted to match the coverage of the clinical plans, and comparison of the PCI, GI and BOT was made.
The average parameters for plans produced using the optimisation module were; coverage 98.7%; Paddick conformity index (PCI) 0.85; GI 2.75, compared to coverage 99.5%; PCI 0.83; GI 2.70 for manual clinical plans with BOT 21% shorter than clinical plans on average. The average parameters for the plans produced by the optimisation module after manual adjustment to match the coverage of the clinical plans were: coverage 99.5, PCI 0.83, GI 2.73 with BOT 16% shorter than clinical plans on average.
The standardised method for using the optimisation module has potential for shortening treatment times and planning times.
本研究的目的是开发一种在Leksell伽马刀治疗计划系统中使用逆向计划模块的标准化方法。
Leksell伽马刀治疗计划系统10版及更高版本包含一个逆向计划模块，该模块由自动用射束填充靶区体积并随后优化其剂量分布的功能组成。针对转移瘤开发了一种使用逆向计划模块的标准化方法，采用以下优化参数权重：{覆盖度0.9，选择性0.1，梯度指数（GI）0.2}。将使用这些参数生成的25个计划与手动生成的临床计划进行比较。此外，对这25个计划进行手动调整以使其覆盖度与临床计划相匹配，并对PCI、GI和BOT进行比较。
使用优化模块生成的计划的平均参数为：覆盖度98.7%；帕迪克适形指数（PCI）0.85；GI 2.75。相比之下，手动临床计划的覆盖度为99.5%；PCI 0.83；GI 2.70，BOT平均比临床计划短21%。在手动调整以使其覆盖度与临床计划相匹配后，优化模块生成的计划的平均参数为：覆盖度99.5，PCI 0.83，GI 2.73，BOT平均比临床计划短16%。
使用优化模块的标准化方法具有缩短治疗时间和计划时间的潜力。
