Radionuclide stent system aided for intravascular irradiation

在包括动脉或TIPS管道在内的支架管腔中，假内膜增生引起的再狭窄或闭塞是一个棘手的问题。在体外，我们研究了使用铱192源的表面剂量为12 Gy的血管内照射，特别参考了弯曲血管模型中铱192 ERAD的等剂量曲线。使用一种新开发的原型双闭塞球囊导管，能够将包含铱192源的柔性导管放置在管腔的中心，获得最佳等剂量曲线。对34例舌癌患者进行了铱192高剂量率放射治疗。对于肿瘤包绕、TIPS、动脉粥样硬化性狭窄或动脉瘤患者，也使用Walistents或Metastern血管支架植入术。这些结果表明，使用双球囊导管和柔性导管（包括192个铱源）的组合进行血管内放射治疗的临床技术可能性。目前正在进行一项实验研究，以评价除血管壁本身外，受辐照血管周围组织的安全性。

Restenosis or occlusion with pseudointimal hyperplasia is a troublesome problem in stenting lumen including arteries or TIPS tract. In vitro, we investigated endovascular irradiation with a surface dose of l2Gy using an Iridium 192 sources, with special reference to Isodose curves of a iridium 192 ERAD in a curved vessel model. Using a newly developed the prototype double occlusion balloon catheter that enabled to place the flexible catheter induding iridium 192 sources in the center of the lumen, optimal isodose curves were obtained. Iridium 192-high dose rate radiotherapy was carried out for the 34 patients with tongue cancer. Endovascular stenting using Walistents or Meadox vascular stent graft was also made for the patients with tumor encasement, TIPS, atherosclerotic stenosis or aneurysm. These results suggest the clinical technical possibility of application of intravascular radiotherapy using this combination of a double balloon catheter and a flexible catheter including 192 Iridium sources. An experimental study is now made to evaluate the safety of the surrounding tissue of the irradiated vessel in addition to the vessel wall itself.