[使用治疗计划系统估计VMAT绝对剂量测量的不确定性由于幻影设置错误]
Tadahiro Mizoguchi1, Yuji Tameshige2, Tatsuya Kaneda1
1Department of Radiological Technology, Fukui Prefectural Hospital.
Nihon Hoshasen Gijutsu Gakkai zasshi
|March 6, 2024
概括
本研究引入了一种方法,通过分析治疗计划系统的剂量梯度来估计VMAT中的剂量测量不确定性. 提出的方法准确地预测测量的不确定性,有助于选择最佳的验证点.
科学领域:
- 医学物理 医学物理
- 辐射瘤学 辐射瘤学
- 辐射疗法质量保证 辐射疗法质量保证
背景情况:
- 在体积调节弧疗法 (VMAT) 中,单点剂量验证需要仔细选择测量点,以避免急剧的剂量梯度.
- 准确评估测量不确定性对于可靠的放射治疗质量保证至关重要.
研究的目的:
- 提出和验证一种方法来估计VMAT中绝对剂量测量的不确定性 (Uplan),特别是解决幻影设置错误.
- 使用从治疗计划系统 (TPS) 计算的剂量梯度来评估适当的剂量验证测量点.
主要方法:
- 使用TPS计算离异中心附近的计划剂量值的剂量梯度.
- 估计的幻影设置错误.
- 根据估计的设置错误开发了一个计算Uplan的公式.
- 使用水幻影和电离室测量离子中心附近的剂量梯度,以计算Umeas.
主要成果:
- 在计划不确定性 (Uplan) 和测量不确定性 (Umeas) 之间观察到高相关性 (系数=0.984).
- Umeas和Uplan之间的平均差异为-0.24%,可能受到电离室的体积平均效应的影响.
结论:
- 计算Uplan的拟议方法有效地反映了由于幻影设置错误引起的绝对剂量测量的不确定性.
- 这种方法对于在VMAT中确定适合绝对剂量验证的测量点有价值.
更多相关视频
08:34Proton Therapy Delivery and Its Clinical Application in Select Solid Tumor Malignancies
Published on: February 6, 2019
20.3K
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
2.8K
相关概念视频
03:37Uncertainty in Measurement: Accuracy and Precision
Scientists typically make repeated measurements of a quantity to ensure the quality of their findings and to evaluate both the precision and the accuracy of their results. Measurements are said to be precise if they yield very similar results when repeated in the same manner. A measurement is considered accurate if it yields a result that is very close to the true or the accepted value. Precise values agree with each other; accurate values agree with a true value.
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.
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...