^(32)P液体球囊在血管内吸收剂量的研究

Study of the endovascular absorbed dose in liquid balloon catheter filled with ^(32)P

目的 研究32 P球囊在血管内的剂量分布。方法 用肌肉等效材料代替血管壁 ,采用热释光剂量学方法模拟测量靶血管轴向和径向吸收剂量率分布 ,并对相关影响因素 (球囊内压力 ,气泡 )进行了研究。结果 3 0mm× 2 0mm 32 P球囊 ,活度为 92MBq时 ,血管表面平均吸收剂量率为0 48Gy min ,在径向 0 4mm处为 0 2 2Gy min。结论 血管壁表面剂量分布较均匀 ,径向剂量随距离迅速衰减 ,但存在诸多影响因素。

Objective To study dose distribution of 32 P liquid balloon in experim ental intravascular brachytherapy. Methods The vessel wall was substituted by muscle equivalent material. Determination o f the dose distribution of axial and radial target vessel wall was performed by thermoluminescence dosimeters. Besides, the influencing factors such as intra- balloon pre ssure and air bubble were also studied. Results In 3.0 mm×20 mm 32 P liquid balloon with radioactivity 92 MBq, th e dose rate in balloon surface is 0.48 Gy/min, whereas in radial 0.4 mm area is 0.22 Gy/min. Conclusions The dose distribution of vessel wall su rface is uniform but the radial dose attenuated rapidly with distance. Ther e are several influencing factors existed.