Intravascular radiation therapy with a Re-188 liquid-filled balloon in patients with in-stent restenosis.

OBJECTIVE: The aim of this study was to evaluate the feasibility and safety of intravascular radiation therapy (IVRT) using Re-188 filled balloon system in patients with in-stent stenosis. METHODS: A total of 39 patients with in-stent restenosis were enrolled as the IVRT (22 patients) and control groups (17 patients) of this study after a successful coronary angioplasty. For irradiation the angioplasty balloon was replaced by a noncompliant balloon of the same diameter but 10 mm longer in length with a proximal and distal radio-opaque marker to deliver the dose of 18 Gy at 0.5 mm depth from the surface of the balloon into the vessel wall. Angiographic follow-up was performed after 6 months. RESULTS: The length of the irradiated segment was between 9.14 and 22 mm and the diameter between 2.5 and 3 mm. In the IVRT group, two patients who did not receive antiplatelet therapy had myocardial infarction. Four patients who presented with stable angina earlier also had angiographically documented in-stent occlusion (two patients) and edge stenosis (two patients) of the target lesion and received angioplasty (18.1%). In the control group, three patients with recurrent angina and four asymptomatic patients had documented in-stent occlusion angiographically at 6 months and these seven patients underwent target lesion revascularization (41.2%). The overall restenosis rate in the IVRT and control groups were 23.91 and 39.86%, respectively (P=0.013). No complications were documented, except anginal pain and ST segment changes. CONCLUSION: Our results indicated that the Re-188 liquid-filled balloon is feasible, safe, and effective in patients with in-stent restenosis.