Mück K, Schmidt W, Wexberg P, Görz W, Maurer G, Gottsauner-Wolf M
Austrian Research Center Seibersdorf.
Int J Radiat Oncol Biol Phys. 2000 Jan 1;46(1):249-55. doi: 10.1016/s0360-3016(99)00350-8.
Post-dilatation irradiation of the vessel wall is currently under investigation for prevention of restenosis after balloon dilatation. For the irradiation, special sources were designed for animal experiments which would give equivalent irradiation conditions and doses to the vessel wall that would later be employed for human application.
For the planned irradiations, a specially designed yttrium-wire of 0.45-mm diameter coated with a thin shrink tube to prevent contamination was deployed. Several leakage tests applied before and after application proved that the irradiation source was leakproof. Dosimetry was performed by using 0.1-mm-thick thermoluminescent dosimeters (TLD-100) calibrated against a primary standard. A shielding transport and application container was designed to facilitate the handling of the source during use, while reducing exposure of the medical personnel.
The designed source proves to be flexible for the insertion into proximal coronary vessels, and positioning at the site of stenosis. It provides an optimum protection of the animal and requires little radiation protection efforts on behalf of the medical staff. Dosimetric calculations and measurements showed that a centering of the source inside the vessel could be achieved with a maximum deviation of 50% between maximum and average dose levels.
A yttrium-90 beta brachytherapy source was designed which provides high flexibility within proximal coronary arteries, ensures an adequate centering inside the artery, and provides irradiation conditions to the vessel wall of the experimental animal comparable to the application inside a human artery.
目前正在研究血管壁的扩张后照射，以预防球囊扩张术后的再狭窄。对于照射，设计了专门用于动物实验的特殊源，其能为血管壁提供与后来用于人体时等效的照射条件和剂量。
对于计划中的照射，部署了一种专门设计的直径为0.45毫米的钇丝，其涂有一层薄的收缩管以防止污染。在应用前后进行的几次泄漏测试证明照射源是防泄漏的。剂量测定通过使用针对一级标准校准的0.1毫米厚的热释光剂量计（TLD - 100）进行。设计了一个屏蔽运输和应用容器，以便在使用过程中便于源的操作，同时减少医务人员的暴露。
所设计的源被证明可灵活插入近端冠状动脉并定位在狭窄部位。它为动物提供了最佳保护，并且医务人员几乎不需要进行辐射防护工作。剂量计算和测量表明，源在血管内的居中可以实现，最大剂量水平与平均剂量水平之间的最大偏差为50%。
设计了一种钇 - 90β近距离放射治疗源，其在近端冠状动脉内具有高度灵活性，确保在动脉内充分居中，并为实验动物的血管壁提供与人体动脉内应用相当的照射条件。
