评估对H&N癌症的VMAT计划中不确定性的影响,考虑到患者设置错误 (PSE)
Arvind Kumar1, Kiran Sharma2, C P Bhatt3
1Graphic Era Deemed to Be University, Dehradun, Uttarakhand, 248002, India; All India Institute of Medical Sciences (AIIMS), Rishikesh, Uttarakhand, 249203, India.
概括
放射治疗中的患者定位错误对用VMAT治疗的头癌症的辐射剂量准确性有重大影响. 超过5mm的误差会损害目标覆盖范围,并影响腺等关键器官.
科学领域:
- 辐射瘤学 辐射瘤学
- 医学物理 医学物理
- 癌症治疗方法 癌症治疗方法
背景情况:
- 精确的辐射剂量传递在放射治疗中至关重要,但不确定性可能导致处方剂量和给药剂量之间的差异.
- 患者定位错误是不确定性的常见来源,可能会损害治疗的有效性和安全性.
研究的目的:
- 调查患者定位不确定性对脑癌体积弧疗法 (VMAT) 辐射剂量准确性的影响.
- 评估未经纠正的定位错误对目标覆盖范围和受风险的器官的影响.
主要方法:
- 分析了670个VMAT治疗计划 (10个临床,660个模拟) 用HalcyonTM线性加速器治疗头癌.
- 包含实际患者定位转移和故意移位 (1-10毫米) 的场景,以评估不确定性影响.
- 使用电子门户成像设备 (EPID) 和Octavius 4D幻影进行剂量计验证,以评估不确定性.
主要成果:
- 当定位错误在所有轴 (X,Y,Z) 上超过5毫米时,目标覆盖率低于V95%的门.
- 两种腺都对患者定位的不确定性表现出显著的敏感性.
- 患者特异性质量保证 (PSQA) 证实了定位错误对剂量输送准确性的重大负面影响.
结论:
- 患者定位错误严重影响头癌VMAT的剂量准确性,需要严格的错误减轻.
- 遵守质量保证,临床指南,成像协议和标准操作程序 (SOP) 是至关重要的.
- 独立的剂量计审计对于验证临床实践中剂量输送的准确性至关重要.
更多相关视频
08:25Radiation Planning Assistant - A Streamlined, Fully Automated Radiotherapy Treatment Planning System
Published on: April 11, 2018
14.7K
07:57Positron Emission Tomography-based Dose Painting Radiation Therapy in a Glioblastoma Rat Model using the Small Animal Radiation Research Platform
Published on: March 24, 2022
2.7K
相关概念视频
00:59Uncertainty: Overview
In analytical chemistry, we often perform repetitive measurements to detect and minimize inaccuracies caused by both determinate and indeterminate errors. Despite the cares we take, the presence of random errors means that repeated measurements almost never have exactly the same magnitude. The collective difference between these measurements - observed values - and the estimated or expected value is called uncertainty. Uncertainty is conventionally written after the estimated or expected value.
00:59Propagation of Uncertainty from Random Error
An experiment often consists of more than a single step. In this case, measurements at each step give rise to uncertainty. Because the measurements occur in successive steps, the uncertainty in one step necessarily contributes to that in the subsequent step. As we perform statistical analysis on these types of experiments, we must learn to account for the propagation of uncertainty from one step to the next. The propagation of uncertainty depends on the type of arithmetic operation performed on...
01:10Propagation of Uncertainty from Systematic Error
The atomic mass of an element varies due to the relative ratio of its isotopes. A sample's relative proportion of oxygen isotopes influences its average atomic mass. For instance, if we were to measure the atomic mass of oxygen from a sample, the mass would be a weighted average of the isotopic masses of oxygen in that sample. Since a single sample is not likely to perfectly reflect the true atomic mass of oxygen for all the molecules of oxygen on Earth, the mass we obtain from this particular...
00:54Uncertainty: Confidence Intervals
The confidence interval is the range of values around the mean that contains the true mean. It is expressed as a probability percentage. The interpretation of a 95% confidence interval, for instance, is that the statistician is 95% confident that the true mean falls within the interval. The upper and lower limits of this range are known as confidence limits. The confidence limits for the true mean are estimated from the sample's mean, the standard deviation, and the statistical factor 't,' or...
01:16Contaminants and Errors
Effective sample preparation is crucial for accurate and reliable laboratory analysis. During this process, two significant sources of error can arise: concentration bias from improper sample splitting and contamination caused by methods used to reduce particle size, such as grinding or homogenization. Identifying and minimizing these potential errors is crucial to ensuring the validity of the analysis.
Another key consideration is determining the appropriate number of samples required to...
Another key consideration is determining the appropriate number of samples required to...