相关实验视频

Updated: May 29, 2025

Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach

Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach

Published on: July 3, 2020

对单个机器和平均机器的增强叶片模型 (ELM) 的剂量测量灵敏度

Rafail Panagi¹, Rhydian Caines¹, Carl G Rowbottom¹

¹Medical Physics Department, The Clatterbridge Cancer Centre NHS Foundation Trust, Liverpool, UK.

Journal of applied clinical medical physics

|February 4, 2025

概括

平均增强叶模型 (ELM) 适用于Varian线性加速器,最大限度地减少治疗计划中的剂量差异. 这种方法在质量保证和患者转移方面提供了潜在的时间和资源节省.

科学领域:

医学物理医学物理
辐射瘤学辐射瘤学
放射治疗技术放射治疗技术

背景情况:

关于在Varian EclipseTM治疗计划中增强叶子模型 (ELM) 参数变化的剂量计影响的数据有限.
需要进一步调查ELM参数的现实变化及其临床相关性.

研究的目的:

在一个大型部门的十个线性加速器中评估ELM参数变化.
评估使用单一,机器平均的ELM用于治疗计划的可行性,以节省时间和资源.
为了使患者在机器之间更轻松地转移.

主要方法:

在Varian TrueBeamTM和EDGETM机器上重新计算了各种地点,技术和能量的临床计划.
使用了机器特定的ELM模型,平均机器模型和异常机器模型.
使用临床相关指标评估目标覆盖率 (例如,PTV D98%,D50%,D2%) 和危险器官 (OAR) 剂量.

主要成果:

平均模型的目标指标最大偏差为<2%,绝对剂量差异<0.07 Gy.
对OAR指标的最大偏差为平均模型的<2%,绝对剂量差异<0.10 Gy.
一个异常机器模型显示出明显更大的偏差,突出显示了机器匹配的重要性.

结论:

使用机器平均的ELM不太可能对匹配良好的机器造成临床上显著的剂量测量差异.
这种方法可以简化质量保证,并促进患者在线性加速器之间移动.
确保跨机器的剂量测量一致性对于可靠实施平均ELM模型至关重要.

关键词:

剂量计叶子间隙间隔的叶子间隔增强的叶子建模增强的叶子建模.多叶合仪多叶合仪

更多相关视频

Measurement of Leaf Hydraulic Conductance and Stomatal Conductance and Their Responses to Irradiance and Dehydration Using the Evaporative Flux Method EFM

Measurement of Leaf Hydraulic Conductance and Stomatal Conductance and Their Responses to Irradiance and Dehydration Using the Evaporative Flux Method EFM

Published on: December 31, 2012

Leaf Area Index Estimation Using Three Distinct Methods in Pure Deciduous Stands

Leaf Area Index Estimation Using Three Distinct Methods in Pure Deciduous Stands

Published on: August 29, 2019

相关概念视频

Light Acquisition

Light Acquisition

In order to produce glucose, plants need to capture sufficient light energy. Many modern plants have evolved leaves specialized for light acquisition. Leaves can be only millimeters in width or tens of meters wide, depending on the environment. Due to competition for sunlight, evolution has driven the evolution of increasingly larger leaves and taller plants, to avoid shading by their neighbors with contaminant elaboration of root architecture and mechanisms to transport water and nutrients.

Mechanistic Models: Compartment Models in Algorithms for Numerical Problem Solving

Mechanistic Models: Compartment Models in Algorithms for Numerical Problem Solving

Mechanistic models play a crucial role in algorithms for numerical problem-solving, particularly in nonlinear mixed effects modeling (NMEM). These models aim to minimize specific objective functions by evaluating various parameter estimates, leading to the development of systematic algorithms. In some cases, linearization techniques approximate the model using linear equations.
In individual population analyses, different algorithms are employed, such as Cauchy's method, which uses a...