开发一种通用的焦点测量方法,适用于钻孔型线材
Hidetoshi Shimizu1,2, Kazuharu Nishitani3, Tomoki Kitagawa1
1Department of Radiation Oncology, Aichi Cancer Center Hospital, Nagoya, Aichi, Japan.
Journal of applied clinical medical physics
|April 8, 2025
概括
一种新方法准确地测量了Radixact线性加速器中的X射线焦点位置,揭示了精确辐射治疗至关重要的轻微偏差. 这种技术可能会提高其他 linac 系统的准确性.
科学领域:
- 医学物理 医学物理
- 放射治疗技术 放射治疗技术
- 辐射瘤学 辐射瘤学
背景情况:
- 精确的放射治疗依赖于线性加速器 (linacs) 中精确的X射线焦点定位.
- 传统的方法是不够的,以评估焦点位置在钻孔类型的Linac系统,如Radixact.
- 焦点位置的偏差可能会损害治疗的准确性.
研究的目的:
- 开发一种用于测量Radixact系统中的X射线焦点位置的新方法.
- 为了评估在这个特定区域的理想焦点位置的偏差.
- 建立一个新的质量保证工具,用于放射治疗的准确性.
主要方法:
- 设计了一个简单的测量系统,其中包含一个金属条和电离室.
- 通过离子化室的逐步移动获得光束形状.
- 焦点偏差是使用不同金属条位置的配置中心差异来计算的.
主要成果:
- 焦点位置偏移在目标高度测定为0.42毫米 (IEC-X) 和-0.36毫米 (IEC-Y).
- 测量不确定性被确定为0.187mm.
- 结果证实,从理想的焦点位置略有偏离.
结论:
- 成功开发了一种新的,准确的方法来评估Radixact系统的X射线焦点位置.
- 这种方法有可能提高其他线性加速器的放射治疗精度,包括像Halcyon.com这样的孔型系统.
- 需要进一步的研究来证实在各种辐射疗法机器中的通用性和适用性.
相关概念视频
Distance Measurements by Taping
Tapes are essential in surveying for accurate, durable, and short-distance measurements. Made from lightweight, nylon-coated steel, they offer flexibility and strength for rugged outdoor use. The nylon coating protects against rust and wear, extending the tape's life. Standard lengths, around 30 meters, are marked in meters and millimeters for precision.Surveyors select tapes based on site conditions and accuracy needs. Lightweight, nylon-coated tapes are commonly used for ease of handling and...
Distance Corrections
To achieve precise distance measurements, especially in surveying and construction, certain corrections must be applied to account for potential sources of error like the standardization errors, temperature variations, and slope adjustments.Standardization error emerges when measurement equipment undergoes changes, such as wear, repairs, or weather impacts. To address this, surveyors compare the equipment’s readings to a standard. This process identifies any deviation that might lead to...
Electronic Distance Measuring Instruments
Electronic Distance Measuring Instruments (EDMs) are essential tools in modern surveying, offering precise distance measurements by emitting electromagnetic signals and calculating the time required for these signals to travel to a target and return. Two primary types of signals are used in EDMs — light waves and microwaves — each suited to specific environmental and distance requirements. Light-wave-based EDMs utilize either infrared or laser light, providing high accuracy over short distances...
Design Example: Measuring Distance Between Two Points with Obstructions
When measuring distances in areas with physical obstructions, such as a lake in a field, surveyors must employ techniques to calculate accurate lengths without direct line measurements. One effective method is the offset technique, which allows for precise distance estimation over inaccessible stretches.In this scenario, a surveyor must measure a side of an area that crosses a lake. Since the measuring tape cannot span the lake, the surveyor begins by establishing a baseline that aligns with...
Leveling Equipment
As leveling involves measuring vertical distances relative to a horizontal line of sight, it requires a graduated rod, called a level rod, for vertical measurements and an instrument called a level for a horizontal sight line. A level includes a high-powered telescope with a mechanism for leveling to ensure the line of sight is horizontal when the bubble in the spirit level is centered. Leveling rods, made of wood, metal, or fiberglass, are graduated in feet or meters and commonly used in two-...
Field Procedure for Staking Out Curves
Staking out curves is an essential process in construction to ensure the accurate alignment of structures along a curved path. This task involves positioning stakes at calculated locations corresponding to the curve's design, effectively translating plans into physical markers in the field. The process begins by determining the geometric parameters of the curve, including the radius, central angle, and tangent distances. These parameters are critical for identifying key points such as the Point...


