Thomadsen B, DeWerd L, McNutt T, DeWerd S, Schmidt D
Department of Medical Physics, University of Wisconsin, Madison 53706, USA.
Med Phys. 1999 Nov;26(11):2471-5. doi: 10.1118/1.598766.
Assessing the strength of individual seed-type sources in ribbon assembles remains a challenge in brachytherapy quality assurance. Geometries to measure a single source in the ribbon usually fail because of low signals if using very thick shielding to block the radiation from the other sources, or contributions from all the other sources if they are not shielded well. A normal well-type chamber with partial lead shielding forming a small slot provides a differential response along the chamber axis that, through a deconvolution/simultaneous-equations technique, sorts the contributions from each source, allowing the derivation of each source's strength.
在近距离放射治疗质量保证中，评估带状组件中单个种子源类型的强度仍然是一项挑战。用于测量带状物中单个源的几何结构通常会失败，原因是如果使用非常厚的屏蔽来阻挡来自其他源的辐射，信号会很低；或者如果其他源屏蔽不好，就会受到所有其他源的影响。一个带有部分铅屏蔽形成小槽的普通井型电离室沿电离室轴提供差分响应，通过解卷积/联立方程技术，对每个源的贡献进行分类，从而可以得出每个源的强度。
